The official Campagnolo WRL discussion thread

[Charles M]

Originally Posted by pinoymamba

Daniel Holloway raced crits on 52/36 😂

Yeah, but he only won like 15-20 national titles and since he was a Crit specialist, he lacks the broader knowledge of a forum poster...


The best part of the 10-cog horror... It costs less than 1 watt... (Per Campagnolo/Kogel and a few others) versus the 11 (which by the way, we are all ignoring the 11 has more friction than a 12... which has more friction than a 13)

I say "less" than, because the number of places that can consistently detect the less than single watt loss is countable on one hand (and that hand could be from a not particularly good Yakuza soldier...)



Maybe SRAM could best put this bull%h!t to rest... (though they use % rather than watt loss - While also explaining why even the % loss has to be an estimate because apples to apples testing is pretty difficult)

Oh, and Pro's have been running 10 cogs for a few years, but anyway...


SRAM:

Cogs on the small end of the cassette have been shrinking ever smaller throughout the evolution of multi-speed road bikes, and for good reason. With X-Range gearing found on SRAM RED and Force eTap AXS, that number is now down to 10 teeth.
Why?

Interestingly, every time that little cassette cog got smaller, it was for the same reasons. For example, front shifting requires big changes to your pedaling cadence and breaks up the rhythm of your ride. These shifts cost rider efficiency and detract from the riding experience. Smaller cogs (like our X-Range 10 tooth cog) allow you to use smaller chainrings to get to the same top speed. If the largest cog on the cassette remains the same size, you can stay in the big ring longer and limit the number of front downshifts you have to make.




Another benefit of shrinking the size of the large chainring is that it reduces the difference in the number of teeth between the two chainrings. This means smoother front shifting while limiting the cadence disruption those shifts cause during your ride. And you can do this while also adding gear range to the drivetrain. We’ve taken advantage of each of these benefits of 10-tooth cogs in our eTap AXS groupsets. It’s what sets X-Range apart from what’s available with traditional road gearing.


Additionally, X-Range offers WorldTour level riders an exclusive gearing advantage over competitors. Some of our pros opt to maintain the same size chainrings found in traditional drivetrains with 11-tooth start cassettes. This gives them an additional 10-tooth cog for a higher top speed. While mere mortals need bottom-end bailout gears, these riders need top-end bailout gears to win races!
Related Image




Is there a downside to 10-tooth cogs?

A common concern expressed by cycling tech enthusiasts is that the smaller cogs get, the less efficient a drivetrain becomes, due to increases in friction between the chain and cog and the added rotation required at each chain link. However, something that is often misunderstood in these discussions is that this efficiency concern only reliably applies when every other component in the system is the same. In other words, a true apples-to-apples comparison requires using all the same components, except the cog you are testing. Outside of applied science discussion circles, this critically important point is often missed.

So, while it’s a scientific fact that (all things being equal) smaller cogs are less mechanically efficient than bigger ones, another fact remains; when comparing 11-tooth start SRAM 11-speed road groups and 10-tooth start SRAM 12-speed road groups, nothing is equal because every component in the system is different in multiple key aspects.
Related Image
An inexhaustive list of these differences include the following:

Chain — Every piece of the chain has different dimensions
Derailleur pulley tooth count — eTap AXS rear derailleur pulleys are one tooth larger
Gear teeth shape and thickness
Chainring design


Put it to the Test

So, for a real apples-to-apples comparison, it's best to compare cogs on the same 12-speed drivetrain. Our internal testing showed that the drop in efficiency between the 11 and 10-tooth cogs came to 1%. To put that in perspective, on the same drivetrain, the drop in efficiency between the 12 and 11-tooth cogs is 0.87%. This means that the delta between the two comes out to just 0.13%. So, the reality is that efficiency doesn't fall off a cliff when riding in the 10-tooth cog.

With that said, admittedly this data doesn't fully resolve the question of efficiency between 11 and 10-tooth cogs, because in order to make an equivalent comparison the gear ratio should be the same between the two. To get the same gear ratio on a 10-tooth cog when using an 11-tooth cog, you need a chainring that is roughly five teeth larger. As we know, this larger chainring provides the efficiency benefit of lower chain tension in the upper drivetrain for the same load. But we’re looking at tenths of a percent in added efficiency due to that. This is because the larger ring increases the number of links required to drive each rotation of the rear wheel. More links rotating equals more friction, so the increased chainring size doesn’t have as much benefit as it seems. So with all else held equal, more chain links moving through the lower drivetrain (the low-tension section where the chain exits the chainring and then goes through the rear derailleur pulleys) incurs more losses, offsetting a portion of the benefit gained in the upper portion of the drivetrain from larger chainrings and cogs.

The point being, we're talking about very small numbers that are largely theoretical outside of a lab test. Out on the road, chain lubrication and cleanliness have a far greater effect on drivetrain efficiency than what can be gained by using an 11-tooth start cassette. Plus, with a traditional cassette, you miss out on other real-world time-saving benefits, like making fewer front shifts.
Looking at the Big Picture

When thinking about the topic of drivetrain efficiency as it relates to small cogs, keep in mind that any time you are using a 10-tooth cog, you are riding at 44kph or more. At these speeds, aero drag makes up about 86% of the resistance a rider has to overcome. The remaining sources of resistance are drivetrain friction and rolling resistance, which come out to just about 5% and 9% respectively when pedaling at 400 watts on flat ground. This means that a 1% improvement in drivetrain efficiency at these speeds would amount to 0.05% less resistance a rider has to overcome (aero + drivetrain + rolling resistance). That's just half of one-tenth of a percent.



Efficiency aside, few riders use their smallest cog for very long in a given day’s riding.^ To put that in perspective, if a rider living in a hilly area spent the same amount of time in their highest gear as they spent reading this article, they would need to ride hundreds of miles to encounter enough terrain to use that gear (actually pedaling, not coasting) at a normal descending cadence.

[callmeishmael]

The pics look better close up, actually. I do wish the lettering on the cranks was bronze, like the new Bora Ultras, but it's a minor detail.

For those interested in a 'neutral' perspective, there's an interesting ~10 minute discussion of this groupset on the latest Escape Collective podcast. One of those involved has actually ridden the groupset (unlike almost all of us here), the program is funded by subscribers not advertisers, and the journalists involved have a reputation for objectivity, so while what they say has obviously not come down from Mount Sinai engraved in stone, I'll take it at face value as an informed and unbiased opinion.

I won't summarise it all from memory - and the podcast is both free and time-stamped so I'd urge anyone interested to go and spend 10 minutes listening to it - but I found their discussion of the ratios, the move away from thumbshifters, and the likely reaction of existing customers, to be interesting and balanced.

It was also confirmed that it was stated at launch that not all sponsored riders would be on the new groupset going forward (which produced perhaps less helpful speculation).

[Mark McM]

Originally Posted by Charles M

The best part of the 10-cog horror... It costs less than 1 watt... (Per Campagnolo/Kogel and a few others) versus the 11 (which by the way, we are all ignoring the 11 has more friction than a 12... which has more friction than a 13)

Perhaps you've seen this drivetrain friction test performed by Ceramic Speed that was published in Velonews? They found much high differences in losses than in the SRAM marketting spiel. In particular, they found that the 48/10 gear had signification greater loss than a 53/11 gear, even though they were nearly the same gear ratio. While the 53/11 had a loss of about 13 W (or about 5.2% of the 250 W load), the 48/10 had a loss of about 19 Watt (or about 7.6% of the 250 W load).

[peanutgallery]

Exactly, works on paper when you math it out...reality...it feels terrible

Pro Tour isn't MAMIL riding

Originally Posted by Mark McM

Perhaps you've seen this drivetrain friction test performed by Ceramic Speed that was published in Velonews? They found much high differences in losses than in the SRAM marketting spiel. In particular, they found that the 48/10 gear had signification greater loss than a 53/11 gear, even though they were nearly the same gear ratio. While the 53/11 had a loss of about 13 W (or about 5.2% of the 250 W load), the 48/10 had a loss of about 19 Watt (or about 7.6% of the 250 W load).

[peanutgallery]

Campy isn't even making a 52-36 for this kit, just a 50-34. I'm betting the one pro tour team using campagnolo uses something other than what is offered in this new kit

Doesn't matter, no US distributor has availability for like a year. By then, the bar will be raised

When available, looks to be geared for the crowd that summers in Montauk, not racers

Originally Posted by Charles M

Yeah, but he only won like 15-20 national titles and since he was a Crit specialist, he lacks the broader knowledge of a forum poster...


The best part of the 10-cog horror... It costs less than 1 watt... (Per Campagnolo/Kogel and a few others) versus the 11 (which by the way, we are all ignoring the 11 has more friction than a 12... which has more friction than a 13)

I say "less" than, because the number of places that can consistently detect the less than single watt loss is countable on one hand (and that hand could be from a not particularly good Yakuza soldier...)



Maybe SRAM could best put this bull%h!t to rest... (though they use % rather than watt loss - While also explaining why even the % loss has to be an estimate because apples to apples testing is pretty difficult)

Oh, and Pro's have been running 10 cogs for a few years, but anyway...


SRAM:

Cogs on the small end of the cassette have been shrinking ever smaller throughout the evolution of multi-speed road bikes, and for good reason. With X-Range gearing found on SRAM RED and Force eTap AXS, that number is now down to 10 teeth.
Why?

Interestingly, every time that little cassette cog got smaller, it was for the same reasons. For example, front shifting requires big changes to your pedaling cadence and breaks up the rhythm of your ride. These shifts cost rider efficiency and detract from the riding experience. Smaller cogs (like our X-Range 10 tooth cog) allow you to use smaller chainrings to get to the same top speed. If the largest cog on the cassette remains the same size, you can stay in the big ring longer and limit the number of front downshifts you have to make.




Another benefit of shrinking the size of the large chainring is that it reduces the difference in the number of teeth between the two chainrings. This means smoother front shifting while limiting the cadence disruption those shifts cause during your ride. And you can do this while also adding gear range to the drivetrain. We’ve taken advantage of each of these benefits of 10-tooth cogs in our eTap AXS groupsets. It’s what sets X-Range apart from what’s available with traditional road gearing.


Additionally, X-Range offers WorldTour level riders an exclusive gearing advantage over competitors. Some of our pros opt to maintain the same size chainrings found in traditional drivetrains with 11-tooth start cassettes. This gives them an additional 10-tooth cog for a higher top speed. While mere mortals need bottom-end bailout gears, these riders need top-end bailout gears to win races!
Related Image




Is there a downside to 10-tooth cogs?

A common concern expressed by cycling tech enthusiasts is that the smaller cogs get, the less efficient a drivetrain becomes, due to increases in friction between the chain and cog and the added rotation required at each chain link. However, something that is often misunderstood in these discussions is that this efficiency concern only reliably applies when every other component in the system is the same. In other words, a true apples-to-apples comparison requires using all the same components, except the cog you are testing. Outside of applied science discussion circles, this critically important point is often missed.

So, while it’s a scientific fact that (all things being equal) smaller cogs are less mechanically efficient than bigger ones, another fact remains; when comparing 11-tooth start SRAM 11-speed road groups and 10-tooth start SRAM 12-speed road groups, nothing is equal because every component in the system is different in multiple key aspects.
Related Image
An inexhaustive list of these differences include the following:

Chain — Every piece of the chain has different dimensions
Derailleur pulley tooth count — eTap AXS rear derailleur pulleys are one tooth larger
Gear teeth shape and thickness
Chainring design


Put it to the Test

So, for a real apples-to-apples comparison, it's best to compare cogs on the same 12-speed drivetrain. Our internal testing showed that the drop in efficiency between the 11 and 10-tooth cogs came to 1%. To put that in perspective, on the same drivetrain, the drop in efficiency between the 12 and 11-tooth cogs is 0.87%. This means that the delta between the two comes out to just 0.13%. So, the reality is that efficiency doesn't fall off a cliff when riding in the 10-tooth cog.

With that said, admittedly this data doesn't fully resolve the question of efficiency between 11 and 10-tooth cogs, because in order to make an equivalent comparison the gear ratio should be the same between the two. To get the same gear ratio on a 10-tooth cog when using an 11-tooth cog, you need a chainring that is roughly five teeth larger. As we know, this larger chainring provides the efficiency benefit of lower chain tension in the upper drivetrain for the same load. But we’re looking at tenths of a percent in added efficiency due to that. This is because the larger ring increases the number of links required to drive each rotation of the rear wheel. More links rotating equals more friction, so the increased chainring size doesn’t have as much benefit as it seems. So with all else held equal, more chain links moving through the lower drivetrain (the low-tension section where the chain exits the chainring and then goes through the rear derailleur pulleys) incurs more losses, offsetting a portion of the benefit gained in the upper portion of the drivetrain from larger chainrings and cogs.

The point being, we're talking about very small numbers that are largely theoretical outside of a lab test. Out on the road, chain lubrication and cleanliness have a far greater effect on drivetrain efficiency than what can be gained by using an 11-tooth start cassette. Plus, with a traditional cassette, you miss out on other real-world time-saving benefits, like making fewer front shifts.
Looking at the Big Picture

When thinking about the topic of drivetrain efficiency as it relates to small cogs, keep in mind that any time you are using a 10-tooth cog, you are riding at 44kph or more. At these speeds, aero drag makes up about 86% of the resistance a rider has to overcome. The remaining sources of resistance are drivetrain friction and rolling resistance, which come out to just about 5% and 9% respectively when pedaling at 400 watts on flat ground. This means that a 1% improvement in drivetrain efficiency at these speeds would amount to 0.05% less resistance a rider has to overcome (aero + drivetrain + rolling resistance). That's just half of one-tenth of a percent.



Efficiency aside, few riders use their smallest cog for very long in a given day’s riding.^ To put that in perspective, if a rider living in a hilly area spent the same amount of time in their highest gear as they spent reading this article, they would need to ride hundreds of miles to encounter enough terrain to use that gear (actually pedaling, not coasting) at a normal descending cadence.

[RoosterCogset]

Silly question, but all thru this thread this has been called the "WRL" -- in my head or off the tongue, this is a mouthful and I don't see that the reviewers or Campy call it the WRL. So why are we?

Even spelled out, "Wireless" is 2 less syllables. Or, let's label it WiRL and give it a catchy name at least.

[glepore]

You guys argue about this like it matters for normal peeps. It doesn't. Campy admits the friction loss, and says for 99 percent of the people buying the group its a non issue, and the pros, they admit will use other stuff when appropriate.

For me, the buttons are an issue. Thumb button was perfect, and if you were in the drops, well, blips or whatever you call them solve that.

No matter, cause I can buy a used Ducati for 5k.

[peanutgallery]

Fausto Coppi and Gino Bartali used that term quite a bit, it's Italian for being undergeared with a lot of drivetrain friction

Originally Posted by RoosterCogset

Silly question, but all thru this thread this has been called the "WRL" -- in my head or off the tongue, this is a mouthful and I don't see that the reviewers or Campy call it the WRL. So why are we?

Even spelled out, "Wireless" is 2 less syllables. Or, let's label it WiRL and give it a catchy name at least.

[yinzerniner]

Originally Posted by Mark McM

Perhaps you've seen this drivetrain friction test performed by Ceramic Speed that was published in Velonews? They found much high differences in losses than in the SRAM marketting spiel. In particular, they found that the 48/10 gear had signification greater loss than a 53/11 gear, even though they were nearly the same gear ratio. While the 53/11 had a loss of about 13 W (or about 5.2% of the 250 W load), the 48/10 had a loss of about 19 Watt (or about 7.6% of the 250 W load).

That’s a test of force 1x 11s. Don’t know if the test had been updated for sram axs 12s

Test protocol

The 1X setup comprised a SRAM Force 1 rear derailleur, 48-tooth X-Sync narrow-wide-tooth (NW) chainring, PC-1170 chain, and 10-42-tooth cassette. The 2X drivetrain included a Shimano Ultegra rear derailleur, 39-/53-tooth chainrings, CN-HG701 chain, and 11-34-tooth cassette.

Another thing to take note of is the affect of chain angle, not only with relation to rings and cassettes in the big/small and small/big cog to ring cross chaining configs, but also on larger cogs and rings. The chain angle is increased when cross chaining in bigger tooth configurations, so larger rings and cogs by themselves don’t ensure efficiency

[callmeishmael]

Originally Posted by yinzerniner

That’s a test of force 1x 11s. Don’t know if the test had been updated for sram axs 12s

Test protocol



Another thing to take note of is the affect of chain angle, not only with relation to rings and cassettes in the big/small and small/big cog to ring cross chaining configs, but also on larger cogs and rings. The chain angle is increased when cross chaining in bigger tooth configurations, so larger rings and cogs by themselves don’t ensure efficiency

The test also involved different chains, cassettes, and jockey wheels. From the most basic of scientific viewpoints it’s not usefully comparable data.

[charliedid]

Originally Posted by merckx

Consider this a like button.

Read my mind.

[rice rocket]

Originally Posted by Charles M

Maybe SRAM could best put this bull%h!t to rest... (though they use % rather than watt loss - While also explaining why even the % loss has to be an estimate because apples to apples testing is pretty difficult)

...


Another benefit of shrinking the size of the large chainring is that it reduces the difference in the number of teeth between the two chainrings. This means smoother front shifting while limiting the cadence disruption those shifts cause during your ride. And you can do this while also adding gear range to the drivetrain. We’ve taken advantage of each of these benefits of 10-tooth cogs in our eTap AXS groupsets. It’s what sets X-Range apart from what’s available with traditional road gearing.

The irony in all the SRAM marketing BS is that they continue to have the worst shifting in the business, even w/ the smaller tooth gap.

[tomato coupe]

Originally Posted by rice rocket

The irony in all the SRAM marketing BS is that they continue to have the worst shifting in the business, even w/ the smaller tooth gap.

[Mark McM]

Originally Posted by yinzerniner

Another thing to take note of is the affect of chain angle, not only with relation to rings and cassettes in the big/small and small/big cog to ring cross chaining configs, but also on larger cogs and rings. The chain angle is increased when cross chaining in bigger tooth configurations, so larger rings and cogs by themselves don’t ensure efficiency

Actually, it's the other way around - cross chaining angles are slightly reduced with large sprocket sizes. Or to be more exact, cross chaining angles are reduced with larger chainring/sprocket size differentials. The cross-chaining angle is the arctan of the lateral offset divided by the length of the free run of chain. As the chainring/sprocket differential increases, the vertical angle of the free run of chain increases, increasing the distance between the points it engages the chainring & sprockets, and thus the the length of the free run of chain.

So, for the same chainring/sprocket size ratio, the differential in sprocket sizes increase, which increases the free length of chain, and thus decreases the cross chaining angle.

[yinzerniner]

Originally Posted by Mark McM

Actually, it's the other way around - cross chaining angles are slightly reduced with large sprocket sizes. Or to be more exact, cross chaining angles are reduced with larger chainring/sprocket size differentials. The cross-chaining angle is the arctan of the lateral offset divided by the length of the free run of chain. As the chainring/sprocket differential increases, the vertical angle of the free run of chain increases, increasing the distance between the points it engages the chainring & sprockets, and thus the the length of the free run of chain.

So, for the same chainring/sprocket size ratio, the differential in sprocket sizes increase, which increases the free length of chain, and thus decreases the cross chaining angle.

I think we’re describing different circumstances. You’re describing differentials while I was describing absolute sizes

I think it was either ZFC or Josh at Silca talked about how larger front chainrings aren’t necessarily more efficient because other than in the straight chainline (ie near middle of cassette) scenario the larger chainring creates a more extreme chain angle.

It’s related to what you’re saying about length of free run of chain. With a 55t front chainring the chain angle at the top and bottom sprockets will be larger than if you have a 50t front chainring, as the free run of chain is shorter.

So the ideal solution for sheer efficiency would be a front chainring config that moves very far/big distance between small and large rings , so it creates as little of a chain angle with maximum free run of chain. And also a system that automatically limits the cogs that each ring can shift into. Shimano and Sram have settings which are somewhat auto, but they’re not really set up to maximize efficiency. Yet.