Trek-Segafredo disagrees with SRAM AXS gearing

[Mark McM]

Not in so many words, but if you read between the lines in this Velonews article (https://www.velonews.com/2020/01/bikes-and-tech/tour-down-under-tech-sram-and-disc-brakes-reign-supreme_503883), Trek-Segafredo doesn't think the 10 tooth sprocket (found on SRAM AXS cassettes) makes any sense for them. I and a number of others have questioned SRAM's use of 10 sprockets, and it looks like Trek-Segafredo is questioning it as well.

From the article:

Unlike Movistar, which is using SRAM groupsets for the first time this season, the Trek-Segafredo team – which made the switch from Shimano to SRAM at the start of 2019 – will have an option of using larger chainrings in 2020. This is a team initiative, as SRAM’s road cycling marketing manager, Jason Phillips, explains: “Trek-Segafredo approached us and asked if we could supply chainrings in, let’s say, a ‘more traditional’ size. We were happy to oblige and riders can now select a 54/41 front combination.”

This ratio option not currently available for public purchases, or even the Movistar team. One of the key features of the AXS groupset, launched in February last year, is that it boasts a 12-speed cassette with a 10-tooth smallest cog. The 10 remains on the Trek-Segafredo bikes that have been fitted with the 54/41 front option – including Richie Porte’s Emonda frame and Mads Pedersen’s custom-coloured Madone. “It translates, roughly, to around the same roll-out as a 57-11,” said SRAM’s team liaison officer, former pro cyclist, Thorsten Wilhelm.

Thorsten Wilhelm's math is wrong - a 54-10 combination is more like a 60-11 (or a 65-12). These are really huge gears, and are unlikely to be used much at all. Instead, what is implied is that they don't really intend to use the 10 tooth sprocket at all, and instead treat the 12spd cassettes that start with a 10t as 11spd cassettes that start with an 11t. If they really believed that riders could use 60-11 gear ratios, they would have already been using huge chainrings.

[FlashUNC]

James Huang reported much the same over at CyclingTips.

Much ado about nothing I think since they're an outlier amongst the rest of the AXS teams these days. Even the Trek Segafredo women's team was on their bog standard chainrings.

[John H.]

Makes me wonder if they block out the 10 cog?

[AngryScientist]

a ten only becomes useful in certain 1x set-ups. i wouldnt want one in a 2x either, but i'm slow and lazy. if i'm going 40+ mph - i'm coasting!

[Mark McM]

I hadn't seen the CyclingTips article before, but having now read it, I pretty much agree with Huang.

Oddly, the Trek-Segafredo's using only 11 sprockets of the AXS 12spd cassette usage might actually improve performance slightly - on the AXS cassette, the 11t sprocket is in the 2nd position, so there is less chain offset, decreasing drivetrain friction a tiny bit over using a traditional 11spd cassette where the 11t sprocket is in 1st position (and has more chain offset).

[saab2000]

I haven’t looked much into this but when the groups came out I hated the idea of a 10-tooth cog.

An 11-tooth makes little sense for most riders, let alone a 10. The whole thing was for gram counters, not serious cyclists.

I like my 53x12-28 or 50x11-28.

Leave the 54x11s for the Sagans of the world and the 60x11s for some seriously genetically engineered cyclists of the future.

[dddd]

I haven’t looked much into this but when the groups came out I hated the idea of a 10-tooth cog.

An 11-tooth makes little sense for most riders, let alone a 10. The whole thing was for gram counters, not serious cyclists.

I like my 53x12-28 or 50x11-28.

Leave the 54x11s for the Sagans of the world and the 60x11s for some seriously genetically engineered cyclists of the future.

I agree, Shimano's 12-28t D-A cassette offers a great gearing range and with modest gaps in the gearing, but sadly they only offer this one at the pricey D-A level.

Mention of the chainline had me doubting, since it is the big end of the cassette where the chainline imposes the greater cross-chaining angle in most cases (especially where sporting cyclists use the big ring almost all of the time). Also, at the highest speeds (where the 11t/12t cogs would be used), only about half of the % speed increase resulting from a proportional power increase is realized, due to aero losses. So the chainline optimized for the small end of the cassette offers only half of much extra speed/power as compared to being optimized at the bigger end of the cassette in terms of elapsed time gained (assuming a more-or-less normal degree of undulation to the road's topography)
I still can't rule out that at some point (and helped by the adoption of electronic shifting), additional 3rd and 4th chainrings might be added and marketed to exploit possible reductions in chainline friction that would mathematically far outweigh their aero and weight penalty. Once 1x has peaked in the marketplace, I predict this will be the way forward (everywhere but in the fat-tire world of course).

Of course in pro racing there will be event- and stage-specific gearing strategies that would never make sense to most of us, such as when trying to give their fastest riders a speed edge while leading a team time-trial. I could see how in such an instance, that a less-efficient 10t cog might not fit in with their best-time strategy.

[FlashUNC]

I haven’t looked much into this but when the groups came out I hated the idea of a 10-tooth cog.

An 11-tooth makes little sense for most riders, let alone a 10. The whole thing was for gram counters, not serious cyclists.

I like my 53x12-28 or 50x11-28.

Leave the 54x11s for the Sagans of the world and the 60x11s for some seriously genetically engineered cyclists of the future.

As someone's whose stock and trade online is hyperbole, I think this is some pretty far end of the curve statements.

Gearing like all things is dependent on where you are. I definitely get use out of a 46 or 48x10 around here. There's a use case for it.

[saab2000]

As someone's whose stock and trade online is hyperbole, I think this is some pretty far end of the curve statements.

Gearing like all things is dependent on where you are. I definitely get use out of a 46 or 48x10 around here. There's a use case for it.

Yes, if we ignore the mechanical losses in smaller cogs. I’m no engineer but this is what I’m told.

I’ll say no more than that because I know no more. But I think it’s all smoke and mirrors and marketing. I’m quite certain with my 53/12x12/28 I’m quite relevant and far more so than in my youth with many fewer total ratios. And I’m far less strong today than in my youth.

We have it good these days. Ride what we like.

[FlashUNC]

Yes, if we ignore the mechanical losses in smaller cogs. I’m no engineer but this is what I’m told.

I’ll say no more than that because I know no more. But I think it’s all smoke and mirrors and marketing. I’m quite certain with my 53/12x12/28 I’m quite relevant and far more so than in my youth with many fewer total ratios. And I’m far less strong today than in my youth.

We have it good these days. Ride what we like.

While I won't discount the engineers, in the real world I notice zero difference and tend to think it's totally overblown. Maybe it matters to Trek Segafredo sprinters at the tip of the spear in a flat race like TDU, but didn't seem to hold Ruth Winder back at all.

But hey, it's not for serious cyclists after all...

[bfd]

Does anyone know if Sram axs 12 is compatible with Campy12? I have an etap 11 drivetrain and use Campy 11 wheels including Chorus 11 12-29 cassette.

Not being a racer, I see no reason why I should get a 10t cog. Heck, I don’t even need an 11t cog, so maybe I’ll stick to 11 speed where I can get a 12-29 or even 12-32 cassette.

Thanks

[saab2000]

While I won't discount the engineers, in the real world I notice zero difference and tend to think it's totally overblown. Maybe it matters to Trek Segafredo sprinters at the tip of the spear in a flat race like TDU, but didn't seem to hold Ruth Winder back at all.

But hey, it's not for serious cyclists after all...

I mostly mean that for most cyclists, most of the time, a 10-tooth cog is a wasted gear and nothing more than a spacer, reducing it to an 11-speed. The compact and sub-compact cranks are for weight reduction.

Of course it’s a serious group set for serious cyclists. I typed poorly. But in the absence of personal choice WRT gearing and cassette size it’s likely not for me. I’ve seen it in person and it’s a nice group. But not my choice with these gearing options.

[simonov]

I mostly mean that for most cyclists, most of the time, a 10-tooth cog is a wasted gear and nothing more than a spacer, reducing it to an 11-speed. The compact and sub-compact cranks are for weight reduction.

Of course it’s a serious group set for serious cyclists. I typed poorly. But in the absence of personal choice WRT gearing and cassette size it’s likely not for me. I’ve seen it in person and it’s a nice group. But not my choice with these gearing options.

Keep in mind the chainrings on the standard setup are much smaller than with traditional gearing. You can't look at the 10 as "10" like it's paired with a 53-tooth ring (again, on the standard setup).

[oldpotatoe]

Not in so many words, but if you read between the lines in this Velonews article (https://www.velonews.com/2020/01/bikes-and-tech/tour-down-under-tech-sram-and-disc-brakes-reign-supreme_503883), Trek-Segafredo doesn't think the 10 tooth sprocket (found on SRAM AXS cassettes) makes any sense for them. I and a number of others have questioned SRAM's use of 10 sprockets, and it looks like Trek-Segafredo is questioning it as well.

From the article:



Thorsten Wilhelm's math is wrong - a 54-10 combination is more like a 60-11 (or a 65-12). These are really huge gears, and are unlikely to be used much at all. Instead, what is implied is that they don't really intend to use the 10 tooth sprocket at all, and instead treat the 12spd cassettes that start with a 10t as 11spd cassettes that start with an 11t. If they really believed that riders could use 60-11 gear ratios, they would have already been using huge chainrings.

I'm surprised sram isn't pushing a 1by for these guys..that's what they want to sell, after all.

[GScot]

I'm surprised sram isn't pushing a 1by for these guys..that's what they want to sell, after all.

1by with the 12 speed cassette on a two speed hub and they'll really be on to something.

[saab2000]

Keep in mind the chainrings on the standard setup are much smaller than with traditional gearing. You can't look at the 10 as "10" like it's paired with a 53-tooth ring (again, on the standard setup).

I'm sure it's a really nice group. Honest. I just like the ability to customize my gearing a bit and I've been able to do that with other brands.

I have no doubt that owning a Sram Red AXS group would be quite satisfying actually. I've seen it in person and it's premium. A bunch of friends have Red Etap and love it.

[ergott]

My favorite gearing is 53/11 with 11/28. I do use the 11. It's not always about spinning out a gear to justify a taller one. I use the 11 when high speed cruising and I want a lower cadence. There is a use for spinning about 75-80 and trying to bring the HR down. Lower cadences put more work in the legs than the lungs.

I love my 11 Etap and not looking forward to the new gearing options. Not buying new stuff anytime soon so I'm good.

[saab2000]

My favorite gearing is 53/11 with 11/28. I do use the 11. It's not always about spinning out a gear to justify a taller one. I use the 11 when high speed cruising and I want a lower cadence. There is a use for spinning about 75-80 and trying to bring the HR down. Lower cadences put more work in the legs than the lungs.

I love my 11 Etap and not looking forward to the new gearing options. Not buying new stuff anytime soon so I'm good.

There are certainly places in my life that a 53x11 would be OK, but they're pretty few and far between at the moment. I can think of times in my competitive days it would have been useful but a 12 was pretty much the smallest cog in those days 30 years ago.

Today I'm mostly covered by a 50/39 and an 11-28 cassette. The jump between the front rings is small and smooth and I can throw on a 36 or 34 if I need to take the bike into the big mountains.

[oldpotatoe]

My favorite gearing is 53/11 with 11/28. I do use the 11. It's not always about spinning out a gear to justify a taller one. I use the 11 when high speed cruising and I want a lower cadence. There is a use for spinning about 75-80 and trying to bring the HR down. Lower cadences put more work in the legs than the lungs.

I love my 11 Etap and not looking forward to the new gearing options. Not buying new stuff anytime soon so I'm good.

30mph..impressive on the flats..I can barely do that downhill.

[ergott]

Sometimes that's rotating through with a small group, sometimes that's soloing off the front. Tailwind does help.

Sent from my Pixel 3 using Tapatalk

[Heisenberg]

i use the 48x10 regularly on descents and have no problem going fast with it not in world tour racing. much hand-wringing over non-applicable stuff.

re: campy 12 cross-compatibility, i’ll check today. AXS 10-33 cassette works fine with campy 12, though.

with axs derailleurs+c12 cassette i’d think the campy chain would work better.

[Dave]

One thing that's interesting with the new AXS 12 is that SRAM has gained range with 12 cogs, but reduced range with chain rings that only have a 13T difference instead of up to 16.

If they don't eventually offer an 11T first cog, then they also need to go even smaller with the chainring offerings. The problem with that is that many frames with fixed front derailleur mounts won't allow the FD to drop low enough. I was just barely able to get the FD on my Colnago C-RS low enough for a 48/32.

SRAM offers a 46/33 crank to give about the same top gear as a 50/11.

The new Campy 48/32 with the an 11-34 is working great for the hilly terrain that I ride. The 48/11 is about the same as a 53/12.

As for compatibility, I have ready of one user who put a SRAM AXS 12 cassette on his bike with Campy SR12 EPS and it worked fine, with the Campy chain. There was a thought that maybe EPS could adapt to the off brand cassette, better than a mechanical version, but I've read nothing on that subject in the last few months.

There's a thread on weight weenies, where someone measured the total length of both brands of 12 speed cassettes and found them an even closer match than 11 speed.

I have personally used the AXS 12 chain on my Campy 12 bikes and it works with no problem. I have decided to not buy any more AXS chains, since I see no advantage to using them at present, but I will continue to include them in my regular chain rotation. I recently bought two more Campy 12 chains, so I have six chains to alternate on two bikes. I will take me a long time to wear-out all of those, riding no more than 4,000 miles per year.

[prototoast]

Making the front smaller allows for more range in the back while staying within the limits of common derailleur capacity, at the expense of a small increase in friction. Making the front larger allows for smaller changes in gear ratio between cogs, with a small decrease in friction.

I 100% understand why Trek would want larger chainrings (at least outside of the mountains), but I also don't think Sram's approach is bad for the majority of their customers.

[chiasticon]

total guess: it's more about the cruising gears than the gearing range.

personally, if I find that I'm constantly shifting between two cogs at a given speed, because the cadence doesn't match what my legs want to do, I move to the other ring and try to find the right cog there. but what if that doesn't work either? maybe that's what the Trek team keeps finding themselves up against; hence the change.

[benb]

I can get that this stuff is going to work for some riders but I am very skeptical that any of SRAMs non traditional road designs have come about because of feedback from Pros.

I really think this stuff was brainstormed after comments from amateurs, was designed for amateurs, and is being marketed for amateurs.

They are just not solving problems that the really strong/fast guys were having IMO and sometimes seeming to cause problems for those guys.

I still think almost all of this going back a LONG time now all came about from amateurs who didn't want to be seen riding a Triple.

[benb]

total guess: it's more about the cruising gears than the gearing range.

personally, if I find that I'm constantly shifting between two cogs at a given speed, because the cadence doesn't match what my legs want to do, I move to the other ring and try to find the right cog there. but what if that doesn't work either? maybe that's what the Trek team keeps finding themselves up against; hence the change.

Yes I think this is probably an excellent hypothesis. I haven't tried the new SRAM stuff but this is very very much my feeling with a traditional big ring setup vs a compact setup. The compact always seems to produce more cases where there's something annoying going on when cruising along, and generally as I get more fit this would tend to get more annoying.

A great device here would be a mechanism to count shifts over successive rides of the same course.. maybe some of these systems can already record that, it would be interesting to see if some gearing combinations were causing riders to get annoyed and hunt for the right gear more often.

[weiwentg]

This calls to memory the time Velonews tested (https://www.velonews.com/2019/05/bikes-and-tech/gear-issue-friction-differences-between-1x-and-2x-drivetrains_493185)a Shimano 2x, 53/39, 11-34 system against a SRAM 1x 48t, 10-42 system. At 250W, they said the 2x had about 3W less friction than the 1x, averaged across all gears.

From there, I’d guesstimate that that a 48/33 AXS system could put us at a disadvantage of about 1-3W relative to a 53/39 system in the big gears we’d cruise at (e.g. 53 ring, 14-19t cogs) at 250W. Less of a difference the lower your power. Less of a difference if your reference crankset is 50/34. More of a difference in the biggest cogs, though. I assume that’s why Trek Segafredo is going with bigger rings. Makes sense for their use at their level.

On one hand, that’s not much. I bet most of us can’t consistently detect a 3W penalty blindfolded, let alone a smaller one.

On the other hand, it’s not like I would be eager to pay money to incur a penalty of 2-3W. Some people pay big money to save 3W. And I wouldn’t really jump at the chance to move laterally from Di2 or EPS unless I thought there was some kind of other advantage from moving to AXS. Wireless is nice to install, but I don’t figure I’m going to be installing a bunch of groupsets.

[Mark McM]

I mostly mean that for most cyclists, most of the time, a 10-tooth cog is a wasted gear and nothing more than a spacer, reducing it to an 11-speed. The compact and sub-compact cranks are for weight reduction.

The other reason for 10 tooth sprockets is so that single chainring setups can have a wide range of gears (without needing huge rear sprockets)

Compact cranks are not just for weight reduction. They also allow spreader the chainstays wider (for fatter tires) without chainstay/chainring interference. Single chainring drivetrains allow even more tire clearance.

And sub-compacts are for more than weight reduction - they also allow a wider range of gearing without the need for a triple crank (and all the liabilities introduced by adding an additional chainring).

(On the flip side, not only do 10 tooth sprockets increase friction, they also wear faster, and if the 10 toot sprocket allows the use of smaller chainrings, it also increases the wear rate on the chain and chainrings.)

All told, 10 tooth sprockets make no sense for my riding, and probably don't make any sense for many others either.

[Mark McM]

One thing that's interesting with the new AXS 12 is that SRAM has gained range with 12 cogs, but reduced range with chain rings that only have a 13T difference instead of up to 16.

SRAM says that cassettes with 10 tooth sprockets increases the number of 1 tooth sprocket differentials, which they claim decreases the jump between gear sizes, while at the same time increasing gear range. This is a clear deception. The laws of physics dictate that gear size differentials and gear range must be proportional - for a given number of sprockets, you can't increase one without also increasing the other. SRAM's cassettes with smaller sprockets increase, not decrease, the size jump between gears.

By downsizing the sprockets, SRAM does actually increase the gear range of the cassette as they claim. But by using smaller chainring differentials, their double chainring drivetrains end up with a smaller total gear range then other drivetrains (with standard size cassettes and larger chainring differentials).

There is no doubt that there will be some who like the AXS gearing. But their advertising claims are all smoke and mirrors.

[benb]

And sub-compacts are for more than weight reduction - they also allow a wider range of gearing without the need for a triple crank (and all the liabilities introduced by adding an additional chainring).


I'd once again think this is not a problem the Pro Peloton thought they needed a solution to.

You don't need once of these systems to run 25c tires for road racing or even for 28c for Paris Roubaix, etc..

I'm sure there's somebody who needs an ultra short "crit bike" wheelbase bike that runs 50c tires but I doubt that is a Pro Peloton issue.

[Mark McM]

I'd once again think this is not a problem the Pro Peloton thought they needed a solution to.

The Pro Peloton has frequently used this solution. When races started adding mountains with ridiculously steep pitches (such as the Angliru), racers started using what were previously considered "touring gears". A few used triples, but now that there are lots of Compact options, many now use Sub-compacts. Sub-compact drivetrains in the Pro Peloton is now not uncommon at all during the grand tours.

(Remember, racers were still using single speed bikes after many "tourists" had adopted derailleurs.)

[Heisenberg]

All told, 10 tooth sprockets make no sense for my riding, and probably don't make any sense for many others either.

you should really think about getting your cranks re-anodized.

https://i.imgur.com/eBZnWEB.jpg?1

[82Picchio]

Snip: I mostly mean that for most cyclists, most of the time, a 10-tooth cog is a wasted gear and nothing more than a spacer, reducing it to an 11-speed. The compact and sub-compact cranks are for weight reduction.


I agree with the above and would add that the same is true for the 11-tooth cog on my bikes. It gets use only on straight 8+% descents, of which there are precious few where I ride. For the animals among us, of course, YMMV............

[dddd]

SRAM says that cassettes with 10 tooth sprockets increases the number of 1 tooth sprocket differentials, which they claim decreases the jump between gear sizes, while at the same time increasing gear range. This is a clear deception. The laws of physics dictate that gear size differentials and gear range must be proportional - for a given number of sprockets, you can't increase one without also increasing the other. SRAM's cassettes with smaller sprockets increase, not decrease, the size jump between gears.

By downsizing the sprockets, SRAM does actually increase the gear range of the cassette as they claim. But by using smaller chainring differentials, their double chainring drivetrains end up with a smaller total gear range then other drivetrains (with standard size cassettes and larger chainring differentials).

There is no doubt that there will be some who like the AXS gearing. But their advertising claims are all smoke and mirrors.

I think that there is some quantitative validity to their "increased range" claims made about their 10t cog cassettes.
The difference is that if you take two cassettes, each with say six 1-tooth shift gaps, the cassette with the 10t (vs. 11t) first cog offers greater range across those first seven cogs (or six shift gaps).

Since a 1t shift gap from 10t to 11t is not too big of a gap, they are exploiting the proportionally-greater change of ratio offered by smaller cogs, despite the other problems that you mentioned like chain friction and sprocket wear.

At my age I still like having tall gears for all of the even gentle descents here in the foothills. But I ride several vintage bikes mostly and find that I don't really need any taller gears than 50/12 or even 52/13t, especially when 27" wheels might be part of the equation. I feel like 52/12t is pretty tall, so works out well when I have at least seven cogs in back.

The 50-39t chainset is a great one that was once popular on 1960's Schwinns and also on quite a few early Dura-Ace cranksets out of the box. Combined with at least a 7-speed cassette with 12t top cog makes for useful and user-friendly gearing.

Up through the 10s era, Shimano still offered "B"-series 50t 130mm chainrings to be combined with their most-common B-39t chainring available at the Dura-Ace level and for a time I believe 105 as well.

Here's one of my 50-39t setups, paired with 12-26t and 1/2" clipless pedals:
https://live.staticflickr.com/7059/6832436050_9ebc5b6e30_c.jpg

[Dave]

When cassettes have no larger than an 11T for the first cog that is seldom used, that's when changing to cranks with smaller rings is the best option.

The 48/11 on my bike is used on some of the more minor downhills, when there's a tail wind, or at the start of a descent, I'll wind it up to 38 mph, before coasting.

[Mark McM]

I think that there is some quantitative validity to their "increased range" claims made about their 10t cog cassettes.

Yes, I did agree that the use of a 10 tooth sprocket can increase the gear range (for the same differential between small and large sprocket). For example, compare an AXS 10-33 cassette with a Campagnolo 11-34 cassette: Both cassettes have the same sprocket size differential of 23 teeth, but the AXS cassette has a 3.3:1 range of gears, while the Campagnolo has only a 3.09:1 range.

But SRAM also claims that they can achieve the increase in range without increasing the size jump between gears. This is the deception. Yes, the tooth differentials between sprockets are the same with both cassettes, but the ratio differences don't depend only on the tooth differential, they also depend on the absolute sprocket size. SRAM is just hoping that consumers don't catch the math fallacy behind the deception.

But that's just on the cassette side of the drivetrain. Because SRAM's chainring differentials are smaller than others, the AXS 2x drivetrain actually ends up with a smaller range of gearing than their competitors 2x drivetrains.

[earlfoss]

I'll chime in only to say that I am now on SRAM Force AXS 12 speed, and it's operated great for me. I'm a Cat 1 on the road and in the time I've been using it there have been zero issues mechanically, and I haven't felt I'm lacking any level of practicality from it.

It's a new gadget and the options SRAM provides is going to work for 99.9% of the riders out there.

Seems like any move SRAM makes gets met with a lot of haters, but at the end of the day a lot of people are using their products problem-free, and without compromise. Makes for good forum threads though!

[polar8]

Wondering if this means they'll just limit screw block the 10?

[Heisenberg]

I'll chime in only to say that I am now on SRAM Force AXS 12 speed, and it's operated great for me. I'm a Cat 1 on the road and in the time I've been using it there have been zero issues mechanically, and I haven't felt I'm lacking any level of practicality from it.

It's a new gadget and the options SRAM provides is going to work for 99.9% of the riders out there.

Seems like any move SRAM makes gets met with a lot of haters, but at the end of the day a lot of people are using their products problem-free, and without compromise. Makes for good forum threads though!

this.

i'm an ex conti bike racer. it is very ****ing good stuff, and i'd have no issue toeing the line at a euroland stage race with it on my bike.

if we're going down "THEPROSTHEY'REJUSTLIKEUS" dumbrabbithole, the 10-33 cogset is a bit gappy. for general racing and threshold intervals i'd probably size down to the 10-28, which has so many buttery gears in it. paired with the 48/35 it's spicy. if things are flat AF and it's an option, the big chainset+tiny cogs for maximum happy. or just 1x, because that works too. the gaps on the two smaller cassettes are very wee near the bottom of the cassette.

the TS team wanting a big chainset sounds like oldschoolbikeracing being oldschoolbikeracing (hullo, italy). i sincerely wish that PL Armchair Engineer validation could be from teams eeking the last .09% of (very) variable efficiency from their drivetrains, but that is not the case here. for all its faults, it is extraordinarily capable crap.

ps: if you want to sooth your gear range woes, rotor's direct mount round chainring 2x setups work great with it. i've put a few thousand miles on both 48/32 and 46/30 setups.

[bigbill]

I used to bitch about using a Shimano 12-23 8S cassette because it didn't have a 16. Seems pretty minor now.

[Dave]

While Campy may only have a range of 3.09 on the cassette, they have a range of up to 1.5 on the 48/32 crankset, to give a total range of 4.64. SRAM has nearly identical range of 4.6 with the 46/33 and 10-33. That range drops to 4.46 with the 50/37. Campy's 53/39 with an 11-33 is 4.48. It's all a wash, unless you really need a 5/1 top gear.

I like the lower 32/34 compared to the 33/33.

[polar8]

I used to bitch about using a Shimano 12-23 8S cassette because it didn't have a 16. Seems pretty minor now.

Same!!

[oldpotatoe]

The Pro Peloton has frequently used this solution. When races started adding mountains with ridiculously steep pitches (such as the Angliru), racers started using what were previously considered "touring gears". A few used triples, but now that there are lots of Compact options, many now use Sub-compacts. Sub-compact drivetrains in the Pro Peloton is now not uncommon at all during the grand tours.

(Remember, racers were still using single speed bikes after many "tourists" had adopted derailleurs.)

Yup..what was the quote? Cyclo-tourists and nurses?
Variable gears are only for people over forty-five. Isn’t it better to triumph by the strength of your muscles rather than by the artifice of a derailleur? We are getting soft. Give me a fixed gear. – Henri Desgrange first Tour de France organiser

I think it should be mentioned again that more than a few carbon bikes, with brazeon front der tabs, will have difficulty getting the front der low enough on some of these micro compact cranks...again, sram is 'almost' all in on 1by...
It's a new gadget and the options SRAM provides is going to work for 99.9% of the riders out there.

wow, I didn't know sram had that high of a market share..:eek:

[Gummee]

I think it should be mentioned again that more than a few carbon bikes, with brazeon front der tabs, will have difficulty getting the front der low enough on some of these micro compact cranks...again, sram is 'almost' all in on 1by...My CX bike fits that bill. Evidently I don't do enough intervals, so I run a Wickerks 34/44 set during race season.

Can't get the derailleur down far enough, but even with the big gap, it seems to shift.

IME the solution to SRAM front derailleur woes is Shimano. Just like their brakes.

M

[Mark McM]

While Campy may only have a range of 3.09 on the cassette, they have a range of up to 1.5 on the 48/32 crankset, to give a total range of 4.64. SRAM has nearly identical range of 4.6 with the 46/33 and 10-33. That range drops to 4.46 with the 50/37. Campy's 53/39 with an 11-33 is 4.48. It's all a wash, unless you really need a 5/1 top gear.

I like the lower 32/34 compared to the 33/33.

This is basically my point. The SRAM AXS "solution" is much ado about nothing. And in many ways, it adds more to the "con" column than it does to the 'pro' column (at least for 2x systems).

Pro: It uses slightly smaller cassettes, and a slightly smaller outer chainring.

Cons: It adds extra drag (which is not offset by its lower weight), and smaller sprockets will cause faster wear (of the entire drivetrain).


If the AXS 2x group had a smaller than normal inner chainring, then it could have had the benefit of more tire/chainstay chainring - but because it doesn't, the AXS group ends up as a net loss in just about every category.

The only application where the AXS appears to have any advantage is in 1x groups. where it can use a smaller chainring. And many people think SRAM is trying to drive people to 1x systems. But even here, the disadvantages may outweigh the advantages due to lower efficiency and faster wear.

[benb]

The Pro Peloton has frequently used this solution. When races started adding mountains with ridiculously steep pitches (such as the Angliru), racers started using what were previously considered "touring gears". A few used triples, but now that there are lots of Compact options, many now use Sub-compacts. Sub-compact drivetrains in the Pro Peloton is now not uncommon at all during the grand tours.

(Remember, racers were still using single speed bikes after many "tourists" had adopted derailleurs.)

Yah, I understand. I just think that they are using it cause it's available/is the only thing available and the sponsor is really encouraging them to use it.

I don't necessarily think they were begging for it to be designed in the first place. I think it's much more likely SRAM/Shimano/whoever were building it for amateur demand first and then they push it up to the pros for marketing.

The thing with a triple is irrelevant cause a SRAM team can't get a triple anyway, so of course they wouldn't use one. And they never needed it anyway. Anytime they're using anything lower than a 53/39 setup it seems to be limited use for steep mountain days on dedicated climbing bikes. They'd never use anything lower if they had a rule you had to use the same bike/gearing every day of multiple day races.

Likewise they might prefer a 53/39 with a larger spread cassette but if the sponsor/equipment vendor says they don't have that/won't provide it but here's a compact setup then of course they end up with a compact setup.

[fa63]

I saw this on SRAM's Instagram; they are claiming that their chain design results in no additional drivetrain losses with the 10t cog. Would love to see some independent testing results on that claim.

https://uploads.tapatalk-cdn.com/20200124/f3786bdd9d3e4ce38ba4475a2334afa9.jpg

[Heisenberg]

I think it's much more likely SRAM/Shimano/whoever were building it for amateur demand first and then they push it up to the pros for marketing.

pro racing is marketing

[joosttx]

pro racing is marketing

well, that's a very nice way of saying "pro wrestling".

[simonov]

I'll chime in only to say that I am now on SRAM Force AXS 12 speed, and it's operated great for me. I'm a Cat 1 on the road and in the time I've been using it there have been zero issues mechanically, and I haven't felt I'm lacking any level of practicality from it.

It's a new gadget and the options SRAM provides is going to work for 99.9% of the riders out there.

Seems like any move SRAM makes gets met with a lot of haters, but at the end of the day a lot of people are using their products problem-free, and without compromise. Makes for good forum threads though!

For the most part, there are two groups of people. Those that hate everything SRAM does and will find any opportunity to bash the products, make front-shifting jokes, etc.. And those that actually use SRAM from the last couple of generations.

I've got groups from all the manufacturers, mechanical and electronic, and I ride a lot and put my gear through hard riding and bad weather. SRAM has been as reliable, or in some cases more reliable, than groups from the other guys. The same goes for all the people I ride with who also use a variety of groups. But the reality makes for less entertaining threads in winter, so there's that.

[ChristianWong]

For the most part, there are two groups of people. Those that hate everything SRAM does and will find any opportunity to bash the products, make front-shifting jokes, etc.. And those that actually use SRAM from the last couple of generations.

I've got groups from all the manufacturers, mechanical and electronic, and I ride a lot and put my gear through hard riding and bad weather. SRAM has been as reliable, or in some cases more reliable, than groups from the other guys. The same goes for all the people I ride with who also use a variety of groups. But the reality makes for less entertaining threads in winter, so there's that.

I want to like the AXS stuff, I really do. The 10t doesn't bug me too much, not like I'd spend much time in it anyways. I'd love to go wireless on my upcoming (gravel bike) build but so much of what SRAM is putting out with this group makes me want to stay firmly in the Di2/11-speed era.

-No cassette option in the 10-42 range, have to choose between the comically large 10-50 and the too small 10-33
-New chain standards and they're not even compatible between MTB & Road (!!!)
-No firmware updates for existing 11-speed eTap users, makes me hestitant to commit to a group that might become obsolete quickly (have you tried finding 11-speed eTap groups/parts lately?)
-Red looks great ($$$) but they made Force look so ugly I won't even consider it

[oldpotatoe]

I want to like the AXS stuff, I really do. The 10t doesn't bug me too much, not like I'd spend much time in it anyways. I'd love to go wireless on my upcoming (gravel bike) build but so much of what SRAM is putting out with this group makes me want to stay firmly in the Di2/11-speed era.

-No cassette option in the 10-42 range, have to choose between the comically large 10-50 and the too small 10-33
-New chain standards and they're not even compatible between MTB & Road (!!!)
-No firmware updates for existing 11-speed eTap users, makes me hestitant to commit to a group that might become obsolete quickly (have you tried finding 11-speed eTap groups/parts lately?)
-Red looks great ($$$) but they made Force look so ugly I won't even consider it

Into the corner for a time out for YOU!!:) I guess you are in the .1%

Simonov writes
For the most part, there are two groups of people. Those that hate everything SRAM does and will find any opportunity to bash the products, make front-shifting jokes, etc..

Why do you suppose that is? Serious question...BTW-
A SRAM 12 is the new XD/R driver style. It won't fit on a Shimano 11 or 12 speed micro spline hub. It won't even fit the 11 speed SRAM hubs. Totally different style.

When Campag did this, from 8s to 9s..people HOWLED(not in a good way). When shimano did this 10s to 11s.people HOWLED(not in a good way)...when sram does it with 12s...
crickets...

[Oo0cH]

I want to like the AXS stuff, I really do. The 10t doesn't bug me too much, not like I'd spend much time in it anyways. I'd love to go wireless on my upcoming (gravel bike) build but so much of what SRAM is putting out with this group makes me want to stay firmly in the Di2/11-speed era.

-No cassette option in the 10-42 range, have to choose between the comically large 10-50 and the too small 10-33
-New chain standards and they're not even compatible between MTB & Road (!!!)
-No firmware updates for existing 11-speed eTap users, makes me hestitant to commit to a group that might become obsolete quickly (have you tried finding 11-speed eTap groups/parts lately?)
-Red looks great ($$$) but they made Force look so ugly I won't even consider it

Would it - in theory - be possible to use a rotor 12 speed cassette? They have 11-36, 11-39, 11-46 and 11-52 cassettes, pair them with a 1x chainring and AXS eagle derailleur and voila: Mix-and-Match 12 speed. I wont be trying this myself though, no way in hell im paying € 334 for a casette that i have to replace eventually.

[benb]

For the most part, there are two groups of people. Those that hate everything SRAM does and will find any opportunity to bash the products, make front-shifting jokes, etc.. And those that actually use SRAM from the last couple of generations.


Most of us who are skeptical gave SRAM thousands of dollars over several generations and got burned more than once.

Now SRAM comes out with ultra expensive stuff that is drastically redesigned every year, it's a hard leap to take.

For me personally:
- Bait and switch on repairability/maintenance
- Bait and switch on warranty/worse warranty than competitors (racing voiding the warranty)
- Poor material quality resulting in parts wearing out way too quickly for their price level
- Weight weenie design that exacerbated wear and tear from poor choice of materials
- Poor front shifting experiences

[Mark McM]

I saw this on SRAM's Instagram; they are claiming that their chain design results in no additional drivetrain losses with the 10t cog. Would love to see some independent testing results on that claim.

https://uploads.tapatalk-cdn.com/20200124/f3786bdd9d3e4ce38ba4475a2334afa9.jpg

Is this from the same people who put out full page ads claiming that electronic shifting (already available from Shimano and Campagnolo but not SRAM) was an unnecessary gimmick - and then jumped whole-heartedly into electronic shifting?


There have been multiple tests showing that SRAM's chains in general are less efficient than their competitors. Here is a test that shows that their 12spd chains are less efficient than other manufacturers 11spd chains - and this is before you add the 10 tooth sprocket:

https://cyclingtips.com/2019/12/the-best-bicycle-chain-durability-and-efficiency-tested/#efficiency-comparison

https://cdn-cyclingtips.pressidium.com/wp-content/uploads/2019/11/CeramicSpeed-chain-efficiency-testing-2020-UFO-V2-figures.jpg

[Heisenberg]

Would it - in theory - be possible to use a rotor 12 speed cassette? They have 11-36, 11-39, 11-46 and 11-52 cassettes, pair them with a 1x chainring and AXS eagle derailleur and voila: Mix-and-Match 12 speed. I wont be trying this myself though, no way in hell im paying € 334 for a casette that i have to replace eventually.

they work great with road AXS too.

been playing with lots of combos. the road stuff is generally functional/cross compatible with other 12s setups, the only hitch i’ve found is when using a non-flat top chain is it’s noisy with the AXS road cassettes.

[benb]

< 2 Watts difference @ 250W (I think?) between the best & worst chain in that test.

No disclosure of margin of error in the article.

Article doesn't fully explain that test. It does make me think SRAM has a point that not setting the test up just right with just the right matching parts could be leading to misleading results.

If you can believe 2 watts with no disclosure of margin of error is significant.

I think most of us are not keeping our chains perfectly clean enough & lubricated perfectly well enough to need to care about this.

The durability tests are more interesting to me but a test showing 2W difference between the best and worst setups would never influence my buying decisions.

[Dave]

The test of the AXS chains seems to indicate that they break-in to become more efficient. Don't know why they quit the test of the Red AXS chain so early.

I'm not impressed with the use of the KMC digital caliper. Different brands may have slightly different roller diameters and hole sizes in the rollers that foul up the "wear" measurement. I hope that each brand was given an appropriate starting point and not considered partially worn, when new. The design standard only lists a maximum roller diameter. New chains will most often have rollers that are about .001 inch smaller than the maximum.

It is possible for a chain to show little change in pitch, but be very worn out. When I did some chain wear measuring on Campy 10 chains, I found extremely worn rollers and greatly increased side clearances, but little elongation, after 6,000 miles. I measured the elongation properly - pin to pin over the entire length. Despite the small change in pitch the chain was extremely worn and should have been tossed, long before 6,000 miles. The cassette that this chain was used with had new-chain skip when a new chain was installed, showing that roller based wear measurements have some relevance. It's also why I alternate the use of several chains, so I never get new-chain skip. A chain with even a few hundred miles of use will not skip on worn sprockets, where a new chain will.

[simonov]

Most of us who are skeptical gave SRAM thousands of dollars over several generations and got burned more than once.

Now SRAM comes out with ultra expensive stuff that is drastically redesigned every year, it's a hard leap to take.

For me personally:
- Bait and switch on repairability/maintenance
- Bait and switch on warranty/worse warranty than competitors (racing voiding the warranty)
- Poor material quality resulting in parts wearing out way too quickly for their price level
- Weight weenie design that exacerbated wear and tear from poor choice of materials
- Poor front shifting experiences

Well, I've been using SRAM since Force 10speed and my experience has been completely opposite of yours. I've had two parts fail on me. A Force 11 rear derailleur and right shifter after about 30K miles. Front shifting with 10 speed was sub-par, but everything since the Yaw design came out is great. Better than shimano or campy, in my opinion. Most shops just don't bother to take the time to set it up properly or try to set it up like it's an old 7700 FD. I can think of a couple experiences where they did a warranty replacement on parts that weren't even broken because the shop insisted. By comparison, I've had campy FDs explode on me and countless issues with various parts from Shimano. Cassettes with manufacturing defects so they just won't run smooth in certain gears, the abomination of the first gen hydro road lever design, clearance and setup issues with the long arm FD design...I'm still a fan, though, because on balance they make some great stuff too. All the groups at this point are very good, but none of them are perfect and none of them are trash.

As for drastically redesigned stuff every year...SRAM mechanical hasn't changed in ages and eTap gen1 was out for like 3 years before gen2 came out. If I recall correctly, the first gen Di2 also wasn't compatible with gen2 when it came out a few years later.

[oldpotatoe]

Mark writes
The only application where the AXS appears to have any advantage is in 1x groups. where it can use a smaller chainring. And many people think SRAM is trying to drive people to 1x systems. But even here, the disadvantages may outweigh the advantages due to lower efficiency and faster wear.


No doubt about that. Not only 1by but etap, 12s, hydro brake, systems. Which team last year couldn't make their sram (11s) 1by stuff work?
Is this from the same people who put out full page ads claiming that electronic shifting (already available from Shimano and Campagnolo but not SRAM) was an unnecessary gimmick - and then jumped whole-heartedly into electronic shifting?

Ha, yup, 'batteries not required', but then a group with 4 of them.
I also liked the ad that said sram RTC, Return To Center tri bike//TT bike barends were 'more aero'..throw in the stuff about their 12s chain efficiency.

Plus the blog or whatever from a sram dude who basically criticized anybody in the industry who isn't embracing hydro road disc brakes.

YUP, all 3 brands make decent stuff these days...but initial road group component failures, 2 recalls I know of, the biggy being their disc brakes, and getting yelled at by the US 'big boy' at sram, twice(yes socalsteve, still makes me angry)...well, sram anything pretty far down on my list, not only in the shop but today.

I also think, that in spite of the 2 teams in the pro peloton, the lack of a sram mechanical 12s road group is not grand. Does sram even MAKE a etap, 12s, rim brake group? Donno.

The 'advantage' of DA and SR mechanical, as per both shimano and Campag, was to ensure mechanical road groups don't become irrelevant, because a LOT of people still want mechanical(majority, in fact).

So, another 'which group is best' discussion and yup, some love whichever but 'criticism' or praise, of whatever 'stuff', is well founded by those of us who were and are, in the trenches. :)

[marciero]

...
But SRAM also claims that they can achieve the increase in range without increasing the size jump between gears. This is the deception. Yes, the tooth differentials between sprockets are the same with both cassettes, but the ratio differences don't depend only on the tooth differential, they also depend on the absolute sprocket size. SRAM is just hoping that consumers don't catch the math fallacy behind the deception.

But that's just on the cassette side of the drivetrain. Because SRAM's chainring differentials are smaller than others, the AXS 2x drivetrain actually ends up with a smaller range of gearing than their competitors 2x drivetrains.

This. The single tooth jumps get bigger as teeth get smaller. This is why the jumps between cogs on, say, an 11-32 or 11-36 cassette go from 1 to 2 to 3 to 4 teeth as the cogs get bigger. But for the smaller cogs there has only ever been a one-tooth jump. This was not a big deal when 13t or even 12t was the smallest cog. No one complains about non-equal jumps between 12-13, 13-14, 14-15. I definitely notice it with 11t small cog. And now with a 10t...
For a 46t ring, the jump going from 11t to 10t is twice the jump from 15t to 14t. (The percentage difference is less than double, but actual ratio change rather than percentage change makes the most sense for comparison here).

When you think about it, the whole "closer ratios" argument that was a main justification for the cog arms race was mostly bogus, because smaller cogs were always being added. And now we have the addition of bigger cogs and one-by.

The only way around the increasingly big jumps at the high end with a traditional drive is to go with smaller chain pitch. It would also address the increased friction 10t. There is no way that engineers have not thought of this and dismissed it for whatever reasons.

Sheldon sure thought of it.

https://www.sheldonbrown.com/nanodrive/

[simonov]

I also think, that in spite of the 2 teams in the pro peloton, the lack of a sram mechanical 12s road group is not grand. Does sram even MAKE a etap, 12s, rim brake group? Donno.

Yes. Yes, they do make an eTap AXS 12s rim brake group. Part of me wishes they'd update their mechanical group to 12, but other than the extra gear, I can't think of anything else I'd change about the current 11speed Force or Red groups.

[Mark McM]

The only way around the increasingly big jumps at the high end with a traditional drive is to go with smaller chain pitch. It would also address the increased friction 10t. There is no way that engineers have not thought of this and dismissed it for whatever reasons.

Sheldon sure thought of it.

https://www.sheldonbrown.com/nanodrive/

Shimano kind of thought of it - but for single speed (track bikes). In the early 1980's Shimano introduced the Dura-Ace 10 track group which used a 10mm pitch chain which is about 20% smaller than our current 12.7mm (1/2") pitch chain. Since you only have one gear ratio on the track, riders tend to be pickier about exactly what gear ratio the choose, and the 10mm pitch chain allowed finer granularity in sprocket sizes.

Maybe the Shimano 10mm pitch chain will be resurrected someday.

https://www.sheldonbrown.com/shimano1982/images/11.jpg

[marciero]

Shimano kind of thought of it - but for single speed (track bikes). In the early 1980's Shimano introduced the Dura-Ace 10 track group which used a 10mm pitch chain which is about 20% smaller than our current 12.7mm (1/2") pitch chain. Since you only have one gear ratio on the track, riders tend to be pickier about exactly what gear ratio the choose, and the 10mm pitch chain allowed finer granularity in sprocket sizes.

Maybe the Shimano 10mm pitch chain will be resurrected someday.



Ahh... And 10mm is such a much nicer number than 12.7! I've always thought it was some crazy coincidence that 1/2" became standard across manufacturers in the first place.

[merckx]

The Dura Ace 10mm track group was introduced in the 70's, maybe around 76/77. It was revolutionary, but never gained market traction.

[Mark McM]

Ahh... And 10mm is such a much nicer number than 12.7! I've always thought it was some crazy coincidence that 1/2" became standard across manufacturers in the first place.

It's likely that the 1/2" became standard for bicycles not long after the roller chain was invented (late 19th century). Is there any other standard component dimension that's been in use for as long as the 1/2" dimension for chain pitch?

Now that I think about it some more, I wonder why a drivetrain manufacturer hasn't tried a different chain pitch standard more recently. Many times over the past few decades manufacturers have released a new component groups which is mostly or completely incompatible with existing component groups - for example, each time a new sprocket has been added to cassette, the manufacturers have insisted that you need to change the entire drivetrain, in which case there's no need to maintain the previous chain pitch.

From what I can see, it wouldn't take a lot of component changes to adapt a new chain pitch. Obviously, you'd need a new chain, plus new chainrings and cassette, but the chainrings and cassette could be made to fit existing cranks and freehubs. You'd need new pulleys on the rear derailleur, but I don't see why any other changes to the derailleur would be required as long as the diameter of the pulleys was roughly the same). And you could probably re-use the front derailleur if the basic diameter of the chainrings was the same. Which means you could keep the same shifters as well.

Since drivetrains have been moving to smaller chainrings and/or sprockets, a move to a smaller chain pitch would seem in line also. When is one of the component companies going to stand up and take this next obvious evolutionary step in the bicycle drivetrain?