Road 1x discussion thread

[ltwtsculler91]

Originally Posted by etu

what do you guys use for the left brake lever if you go 1x with shimano drivetrains.
is there an identically shaped brake lever without the shifter mechanism?

As Wayne77 mentioned, there's no real downside to running a "regular" left shifter with guts if you're using Shimano (or Campy). Its a few extra grams, but remains useful if you decide to go back to 2x or switch the levers to another bike.

The only system where the dummy lever really makes sense is if you decide to go SRAM since the 1x clutched RDs aren't 2x compatible for road/cross bikes

[Bonesbrigade]

Originally Posted by Wayne77

As mentioned, I race road a lot as well... but I obsess about gravel far more than I do Road these days. LOVE IT!!

I agree with technical gravel races being awesome for obsessing about the equipment and race setup - this is a big part of the appeal for me too. I've also likely put waaay too much thought into this!

With that said, this is all very individual, and right now for me, 2x system is the best overall for the racing and riding I do. I just don't see any of the purported advantages of a 1x outweighing what I get from a wide-range 2x. system.

You have to keep in mind, that my "gravel" bike also gets used for fast road rides where I'm using 700x28 tires, and also gets used with 700x38, 700x40, 650x42, 650x48. So...that's a huge consideration for a nice wide gearing like 50-34 paired with various cassettes - 11-28, 11-32, 11-34, 11-36, 11-40.

Anyway, this really is very individual, so it's hard to be prescriptive with comments/opinions.

[Clancy]

Great discussion of which I can add little I imagine, but do have some thoughts/questions.

On my 1X with the clutch on, the shifting is very stiff, clunky almost. Not as smooth up/down shifts. I’ve wondered, does this cause more wear to chain, rings, cogs?

The extreme chainlines is another part of the 1X that makes me wince once in awhile, when in the extreme hi or low. How does that impact wear?

[Bonesbrigade]

Originally Posted by Clancy

Great discussion of which I can add little I imagine, but do have some thoughts/questions.

On my 1X with the clutch on, the shifting is very stiff, clunky almost. Not as smooth up/down shifts. I’ve wondered, does this cause more wear to chain, rings, cogs?

The extreme chainlines is another part of the 1X that makes me wince once in awhile, when in the extreme hi or low. How does that impact wear?

There are definitely some efficiency loses in the drivetrain with a 1x system with a clutch compared to 2x non-clutch. Is it big? I don't think it's huge. Any of the testing I've seen seems to indicate it's no more than 3 or 4 watts in the worst combo. The worst gear combos are actually the smallest cogs - not the biggest. The clutch also causes a bit of drag on the system, but it doesn't seem to be more than 1 or 2 watts according to the tests I saw from Friction Facts.

For chain and cog wear, there must be more wear for sure. I've had my small cogs wear out prematurely on a couple of 1x systems where I always seems to be in the last 3 cogs - I've never had that happen on a 2x system.

[ltwtsculler91]

Originally Posted by Bonesbrigade

....
For chain and cog wear, there must be more wear for sure. I've had my small cogs wear out prematurely on a couple of 1x systems where I always seems to be in the last 3 cogs - I've never had that happen on a 2x system.

I think this may also be due to the fact that for most people they end up using the smallest 3 cogs more on a 1x than a similar 2x set up hence they wear quicker. I know on my 2x road bikes, I'm not in the 11,12, or 13 anywhere near as often as I am on my 1x cross bike

[Bonesbrigade]

Originally Posted by ltwtsculler91

I think this may also be due to the fact that for most people they end up using the smallest 3 cogs more on a 1x than a similar 2x set up hence they wear quicker. I know on my 2x road bikes, I'm not in the 11,12, or 13 anywhere near as often as I am on my 1x cross bike

Yes, that’s the point I was making. If you end up using your 1x bike a lot on the road (assuming you are using a smaller ring 40-44), you will end up prematurely wearing out your smallest cogs. The other issue I mentioned earlier, the smallest cogs are also the least efficient on the cluster - the 11t is less efficient than cross chaining to your largest cog.

[ltwtsculler91]

Originally Posted by Bonesbrigade

Yes, that’s the point I was making. If you end up using your 1x bike a lot on the road (assuming you are using a smaller ring 40-44), you will end up prematurely wearing out your smallest cogs. The other issue I mentioned earlier, the smallest cogs are also the least efficient on the cluster - the 11t is less efficient than cross chaining to your largest cog.

I think we're just agreeing with each other here. I'm running 42t and try to avoid riding the cross bike on "faster" rides for this exact reason, the efficiency and feel of going 20+ is much better mid-cassette on a 50/52/53t ring versus the 1x.

[Bonesbrigade]

Originally Posted by ltwtsculler91

I think we're just agreeing with each other here. I'm running 42t and try to avoid riding the cross bike on "faster" rides for this exact reason, the efficiency and feel of going 20+ is much better mid-cassette on a 50/52/53t ring versus the 1x.

Yes, we are agreeing! I also feel the difference from what you describe.

[Wayne77]

These mentioned 1X downsides in the last few posts are either a given with any CX, gravel, mtb designed primarily for off-road (dirt, grime, mud, is going to wear out any drive train, 2X or 1X, far sooner than the increased use of the smaller cogs on a 1X drive train on the road) or only applicable to Road-specific use cases. I think it’s beem established in this thread and common knowledge that 1X has several downsides to a 2X drive train on asphalt. I think that’s re-stating the obvious. For single track and gravel rides with more gravel than asphalt, lots of extended climbing (The Crusher has 10,000 feet of climbing), lots of technical high speed descents, there is simply no way a 2X drive train is going to be superior to a 1X drive train. There are pros and cons with each, and I choose 1X for the benefits I’ve already called out, which for me, FAR outweigh any gearing advantages of 2X. Those advantages only apply to higher close riding pack speeds.

I have never seen any evidence that this so called innefficiency pedaling a 40/10 on a 1X vs middle of the cassette on a 2X is even remotely measurable. Maybe there is a study out there supporting that, but I am guessing that’s in your head. Probably the same reason people incorrectly thing those large der pulleys are more efficient. They aren’t. There is zero proof of that.

In any case this thread is about Road 1X, not the merits of 1X vs 2X off Road. I’m firmly of the opinion that 1X on the road is a non-stater for me for group rides and absolutely not doable (for me at least) for any competitive Road race around here...except for a few they all have lots of climbing and lots of high speed descending. I do the Lotoja every year - Masters 35+ Cat 4 group. The last two years, the selection occurred on the first long 20 mile descent into Montpelier...not on any of the climbs. Everyone in the top 8 made it into the breakaway that started at the top of Strawberry. The first 10 miles of that descent you are spinning out a 52x11. The only reason that group stayed away (5 min gap to the rest of the field by the time we rolled into Montpelier at the bottom) is because a) we were paying attention as we crested the top and powered our 50/11s and 52/11s as long as we could to create the initial gap b) we were all in super-tuck mode for the first 5 Miles of descending. There is no way anyone with a 1X drive train on their bikes would have been able to hang. They either would have been dropped on the climb because they didn’t have a low enough gear or they would have spun out much sooner on the descent.

[Mark McM]

Originally Posted by Wayne77

I have never seen any evidence that this so called innefficiency pedaling a 40/10 on a 1X vs middle of the cassette on a 2X is even remotely measurable. Maybe there is a study out there supporting that, but I am guessing that’s in your head. Probably the same reason people incorrectly thing those large der pulleys are more efficient. They aren’t. There is zero proof of that.

If you haven't seen any evidence, than it is because you haven't looked for it. The field of engineering has long known that smaller sprockets are less efficient for chain drive systems (consult any handbook of mechanical engineering).

It is true that bicycle applications are a bit different from most machinery chain applications, since bicycle drivetrains tend to be lower speed and higher tension than most chain drives, plus derailleur drivetrains run their chains with far more misalignment than most machines. But, there have been multiple tests of bicycle drivetrain efficiency. For example, these two issues of the Technical Journal of the IHPVA examine chain drive efficiency test data:

http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf


http://www.ihpva.org/HParchive/PDF/hp51-2001.pdf

One of the more recent, and probably most pertinent, chain drive efficiency tests was done by a test house called Friction Facts. Their articles and data are behind a pay-wall, but here is an article from BikeRadar about their testing of 2x drivetrain efficiencies:

http://www.bikeradar.com/us/road/gea...hifting-44016/

Their testing shows not only that smaller sprockets are less efficient, but also that the loss of efficiency in smaller sprockets often overwhelms the losses due to misaligned chains. This means that it is often the case that for the same final gear ratio, a cross-chained gear combination with a large chainring can often be preferable to a well aligned gear combination with small chainring.



Oh, and you're also wrong about there being zero proof that oversized pulleys are more efficient. There have been multiple studies (including by third party groups that don't even make derailleur pulleys) showing that larger pulleys are more efficient. Not a lot more efficient, but it is measurable.

[Bonesbrigade]

Originally Posted by Wayne77

I have never seen any evidence that this so called innefficiency pedaling a 40/10 on a 1X vs middle of the cassette on a 2X is even remotely measurable. Maybe there is a study out there supporting that, but I am guessing that’s in your head. Probably the same reason people incorrectly thing those large der pulleys are more efficient. They aren’t. There is zero proof of that.

As pointed out, you just haven't looked for the studies have already been published - are the drivetrain losses significant for you? That's a personal decision.

This is one of the reasons why a lot of time trialists use very large chainrings in the front 56t - so they can be closer to the middle of their cassettes using larger cogs - more efficient. I've also seen wind tunnel data showing the efficiency gains of the larges cogs with less chain angle more than offsets the small aero penalty of a larger chainring.

Believe me, I like 1x systems. I have 9 bikes, and 6 of them have 1x drivetrains setup. For me, road and gravel bikes just don't make sense with 11speed shifting. I suspect in the next couple of years, those formats will make more sense with 12 and 13 drivetrains coming out. Boost road bikes here we come!

[oldpotatoe]

Originally Posted by ltwtsculler91

As Wayne77 mentioned, there's no real downside to running a "regular" left shifter with guts if you're using Shimano (or Campy). Its a few extra grams, but remains useful if you decide to go back to 2x or switch the levers to another bike.

The only system where the dummy lever really makes sense is if you decide to go SRAM since the 1x clutched RDs aren't 2x compatible for road/cross bikes

Really, so if you changed your mind, had a workable LH shifter or guts and front der..and you wanted to go back to 2by..you'd have to buy a rear der??

[Wayne77]

Thanks for taking the time to post that - I’ll give it a read. Looks like there’s definitely some good info out there that supports this. I stand corrected.

Just like so many other minute gains relating to various cycling components...large der pulleys, ceramic bearings, aero bars, various subtle shaping in aero frame designs, they may all add up to a material increase in efficiency. It’s certainly a way to make the whole system faster. 2 final points, and I’ll let it be:

- I seriously doubt this inneficiecy can actually be felt by anyone on a gravel bike let alone a road bike, as has been claimed. Seriously. Someone tells us a doo-dad is faster and therefore the brain tells us we feel faster. So either we aren’t in reality any faster or if we are it’s because we put more effort into going faster because we’re so dang excited to have something we think is faster. Double blind A-B testing anyone? I would put money down no would be able to consistently discern any difference here.

- This comment isn’t really directed to you but let’s be real. We’re talking gravel biking here. We aren’t pros looking for every single last possible tweak to eeke out a few seconds in a TT. I’d suggest that if inneficiences pedaling a smaller cog at 25mph is any major factor for someone considering 1x vs 2x they are missing the point...and completely ignoring benefits and factors (with 1X or 2X) that DO make a difference and can be felt ...If someone is competitive enough where such marginal gains are important maybe they should look elsewhere for the gains first...maybe get lighter cages :-)

Originally Posted by Mark McM

If you haven't seen any evidence, than it is because you haven't looked for it. The field of engineering has long known that smaller sprockets are less efficient for chain drive systems (consult any handbook of mechanical engineering).

It is true that bicycle applications are a bit different from most machinery chain applications, since bicycle drivetrains tend to be lower speed and higher tension than most chain drives, plus derailleur drivetrains run their chains with far more misalignment than most machines. But, there have been multiple tests of bicycle drivetrain efficiency. For example, these two issues of the Technical Journal of the IHPVA examine chain drive efficiency test data:

http://www.ihpva.org/HParchive/PDF/hp50-2000.pdf

http://www.ihpva.org/HParchive/PDF/hp51-2001.pdf

One of the more recent, and probably most pertinent, chain drive efficiency tests was done by a test house called Friction Facts. Their articles and data are behind a pay-wall, but here is an article from BikeRadar about their testing of 2x drivetrain efficiencies:

http://www.bikeradar.com/us/road/gea...hifting-44016/

Their testing shows not only that smaller sprockets are less efficient, but also that the loss of efficiency in smaller sprockets often overwhelms the losses due to misaligned chains. This means that it is often the case that for the same final gear ratio, a cross-chained gear combination with a large chainring can often be preferable to a well aligned gear combination with small chainring.

[Wayne77]

Snipped:

Originally Posted by Bonesbrigade

This is one of the reasons why a lot of time trialists use very large chainrings in the front 56t - so they can be closer to the middle of their cassettes using larger cogs - more efficient. I've also seen wind tunnel data showing the efficiency gains of the larges cogs with less chain angle more than offsets the small aero penalty of a larger chainring.

Seriously...we’re using elite time trialists and wind tunnel data pertaining to chain angle as examples for Gravel biking?? If you’re that competitive in the gravel races you do, where minute aero or drive train efficiencies matter, my hats off to you sir. I’m nowhere near that competitive and I prioritize convenience, comfort, simplicity, etc far more than I would aero gains and cog size in the world of gravel biking.

Let’s get back on topic (Road 1X). I’ve contributed to beating this dead horse more than than most...There’s indeed a shared passion here and I do enjoy these discussions with people who have a lot of great ideas to share. Thanks a ton for taking the time to share your experiences - good discussion.

[Bonesbrigade]

Originally Posted by Wayne77

Snipped:

Seriously...we’re using elite time trialists and wind tunnel data pertaining to chain angle as examples for Gravel biking?? If you’re that competitive in the gravel races you do, where minute aero or drive train efficiencies matter, my hats off to you sir. I’m nowhere near that competitive and I prioritize convenience, comfort, simplicity, etc far more than I would aero gains and cog size in the world of gravel biking.

Ha, I'm certainly guilty about caring about small details way too much, but no, I'm not optimizing my chainline and cog sizes for gravel races per se! I'm just pointing out there is actual data and testing out there that does conclude there are in fact efficiency considerations in the drivetrain. Whether this single issue matters to you or me wasn't really my point.

However, I do believe that adding up a bunch of small improvements: aero gains, crr, drivetrain efficiency, and weight (and a bunch of other things) can produce a significant advantage - this is the way I approach race bikes.

There is race in the Toronto area called Paris to Ancaster. It is a mixed condition route where you are on rail trails, gravel roads, single track, unmaintained farm fields and paved roads. I believe it is one of the biggest races in NA if I'm not mistaken with well over 1,000 people (maybe more). Anyway, it's hotly contested and there is a variety of terrain you have to account for in terms of tire selection and gearing. This happened to be the first time doing the event last year, so I went into it without much knowledge and poor prep.

My first mistake was being lazy and leaving my 1x cx gearing on there (early spring race) - though I did bump the chainring from 40 to 44, and put an 11-34 cassette on - I knew the route was flatish, so I figured this should be fine. All was good for the majority of the race until the last climb! The finale is 5min. or so climb that is maybe 7 or 8% on a jeep trail. I was in the front chasing group of 8, with 3 people about a minute up (one of them my teammate). So we entered the climb fighting for 4th. The punchy pro guys like Anthony Clark, pro crosser Ian Field from England and a couple of others went ballistic, I was good for the first bit, but my lazy gearing selection completely bogged me down! I was totally going backwards. I ended up finishing 10th 2 or 3 seconds, just behind Adam Myerson.

I'm certainly not blaming a 1x system on this as it was totally my fault for being lazy about not knowing the course and just leaving my cx drivetrain on there. But man, was I wishing I just had my totally versatile 50-34 11-32 system on there. The 2x gearing with wide range can really take the guess work out of preparation when riding in new areas for races or road trips. Kind of a set and forget approach that ticks almost all the boxes.

I agree, great discussion!