How much faster is that new aero bike?

[RunningChoux]

Originally Posted by Jere

I’d like to see how this old junker would stand up against the new ones.

Hey, another Felt AR! Mine is set up pretty similarly with the TriRig front brake, but I'm riding Hed Jet Black wheels for the improved braking overall.

As I have a similar vested interest, I've done some hunting around across what data is public, and I think the answer is "pretty close". I don't have the links on hand, but I recall the Felt being within a watt or two of the top bike(s) in a Tour Magazine wind tunnel test a while back (2016-2018ish?). Their protocol, as I recall, is bike + lower leg dummy, probably at 45 kph. Comparing against newer tests (using other bikes that were included in both sets), it still seems to be within 5 watts? The gap might shrink a watt or two with the aftermarket aero brake. Now, plenty of reasons to still prefer the newer bikes (probably more aero if they included water bottles, more tire clearance, would rather bleed disc brakes than deal with the under-BB rim brake), but I don't think it's holding us back.


To the main point of the thread: when I still care about prentending to be a serious racer, all the aero + rolling resistance + drivetrain toybox comes into play. When there's no finish line? For me, meh. Most of my miles are on round-tubed steel these days, either a Ritchey Breakaway or the Ellis all-road (secondhand from here via the great Clean39t bike carousel).

[ridethecliche]

Those phased out rim brake aero bikes in their final phase were really frikkin aero. In fact I think we've now actually caught up to them in terms of aero and weight compromise.

The rim brake bikes had reached that stage before the transition to disc.

[Mark McM]

Originally Posted by ridethecliche

Those phased out rim brake aero bikes in their final phase were really frikkin aero. In fact I think we've now actually caught up to them in terms of aero and weight compromise.

It's hard to say, as there haven't been true apples-to-apples comparisons. Older rim brake bikes were tested with older wheels and handlebars, and newer disc brake bikes are tested with newer wheels and handlebars. But if you look at some of the white papers published when disc brake aero bikes were first introduced and analyze the aero savings for individual parts (frames, wheels, handlebars, etc.), even though the disc brake aero bikes were just a shade faster, all the savings were from wheels and handlebars, and the frame/fork(/brakes) were actually less aero than rim brake aero bikes. Maybe they've caught up now.

However, generally disc brake aero bikes haven't caught up with disc brake aero bikes in weight. Although the latest disc brake aero bike frames/forks may be shade lighter than the old rim brake aero bike frames/forks, the disc brakes themselves are heavier than rim brakes, and the total disc brake package remains heavier.

[KonaSS]

They have also learned, particularly in the latest generation, how to make a bike that is both aero, and (relatively) comfy to ride. The first couple of generations of aero bikes were all aero and not much about ride quality.

And we have also learned that of all the marginal gains, weight is the least important.

[Mark McM]

Originally Posted by KonaSS

They have also learned, particularly in the latest generation, how to make a bike that is both aero, and (relatively) comfy to ride. The first couple of generations of aero bikes were all aero and not much about ride quality.

One way they made the first generation of aero frames have low aero drag is by making them very narrow, including very tight tire clearances - "narrow is aero" is still true today. Modern aero bikes allow for wider tires, which has increased aero drag.* The * is because we have also learned that total drag is what is important, and while wide tire have more more aero resistance, they also have less rolling resistance, so wider tires have less total resistance. The wider tires also have the benefit of improving comfort and handling.

Originally Posted by KonaSS

And we have also learned that of all the marginal gains, weight is the least important.

This is true to a point, but there are a few asterisks here as well. The faster one rides, the more important aero drag is and the less important weight is, but the opposite is also true - the slower one goes, the less important aero is and the more important weight is. For pro racing cyclists, and even most amateur racers, the extra weight required for aero improvements more than pays off. But for the average cyclist, who rides at lower average speeds and powers, and also may have more stops and starts, the trade-off between aero and weight is not as clear cut.

[cash05458]

Originally Posted by KonaSS

They have also learned, particularly in the latest generation, how to make a bike that is both aero, and (relatively) comfy to ride. The first couple of generations of aero bikes were all aero and not much about ride quality.

And we have also learned that of all the marginal gains, weight is the least important.

Which is kinda funny considering this same industry told us for about 20 years that the most important thing was weight...and had plenty of "studies" to prove that fact.

I don't know but after 40 years of riding and hearing all the "latest" hype things forever and I could go thru a long list...I could really care less about marginal gains at 60 years old.

[Mark McM]

Originally Posted by cash05458

Which is kinda funny considering this same industry told us for about 20 years that the most important thing was weight...and had plenty of "studies" to prove that fact.

For better or worse, UCI regulations play an outsized role on consumer bicycles. UCI racers are just a small part of the bike market, but many consumers want to ride the same bikes that the top racers use, so many of the bikes sold to consumers (unnecessarily) follow the limits imposed by the UCI.

The UCI instituted the current 6.8 kg minimum bike weight limit in 2000. In the years following, the bike industry was able to design and build reliable bikes that were below that limit. There were was even publicity around some bikes needing to have weight ADDED in order to be used by pro teams. Around 2008 or so the bike industry started petitioning hard against the UCI to reduce (or eliminate) the minimum weight limit.

But then in the early 2010's the industry discovered that they could sell more bikes by pushing aero bikes - aero frames, aero wheels, aero handlebars, etc. - and later also by converting to disc brakes. Both features added weight, and bike manufacturers were hard pressed to produce aero bikes with disc brakes that even meet the UCI minimum weight limit, let alone go below it. The industry stopped pushing the UCI to reduce the weight limit, and there's even some indication that they actually petitioned the UCI NOT to reduce the weight limit.

[cash05458]

Originally Posted by Mark McM

For better or worse, UCI regulations play an outsized role on consumer bicycles. UCI racers are just a small part of the bike market, but many consumers want to ride the same bikes that the top racers use, so many of the bikes sold to consumers (unnecessarily) follow the limits imposed by the UCI.

The UCI instituted the current 6.8 kg minimum bike weight limit in 2000. In the years following, the bike industry was able to design and build reliable bikes that were below that limit. There were was even publicity around some bikes needing to have weight ADDED in order to be used by pro teams. Around 2008 or so the bike industry started petitioning hard against the UCI to reduce (or eliminate) the minimum weight limit.

But then in the early 2010's the industry discovered that they could sell more bikes by pushing aero bikes - aero frames, aero wheels, aero handlebars, etc. - and later also by converting to disc brakes. Both features added weight, and bike manufacturers were hard pressed to produce aero bikes with disc brakes that even meet the UCI minimum weight limit, let alone go below it. The industry stopped pushing the UCI to reduce the weight limit, and there's even some indication that they actually petitioned the UCI NOT to reduce the weight limit.

true...appreciate as I think that makes my point...or doesnt...

[Spdntrxi]

Originally Posted by cash05458

true...appreciate as I think that makes my point...or doesnt...

no because back then , the trajectory was bike getting to single use only.

[vespasianus]

Originally Posted by Mark McM

For better or worse, UCI regulations play an outsized role on consumer bicycles. UCI racers are just a small part of the bike market, but many consumers want to ride the same bikes that the top racers use, so many of the bikes sold to consumers (unnecessarily) follow the limits imposed by the UCI.

The UCI instituted the current 6.8 kg minimum bike weight limit in 2000. In the years following, the bike industry was able to design and build reliable bikes that were below that limit. There were was even publicity around some bikes needing to have weight ADDED in order to be used by pro teams. Around 2008 or so the bike industry started petitioning hard against the UCI to reduce (or eliminate) the minimum weight limit.

But then in the early 2010's the industry discovered that they could sell more bikes by pushing aero bikes - aero frames, aero wheels, aero handlebars, etc. - and later also by converting to disc brakes. Both features added weight, and bike manufacturers were hard pressed to produce aero bikes with disc brakes that even meet the UCI minimum weight limit, let alone go below it. The industry stopped pushing the UCI to reduce the weight limit, and there's even some indication that they actually petitioned the UCI NOT to reduce the weight limit.

But if you look at the Triathlon world, they have no such restriction and the bikes can be truly "aero" optimized. That to me is a better place to look for "aero" gains as in the case of the Iron Man Kona, have used the same course for years, you are not allowed to draft and there is no restriction on bike manufacturers to have a certain design. There, over the last 30 plus years, the times have increased by about 5 seconds per mile - which is not trivial if you are racing.

Keep in mind those 5 seconds per mile, could be coming from a wide number of factors, including better fitness, etc but that to me, it gives you a limit to what it could provide in a time trial racing position.

However, I would argue that everyone in the Iron Man Kona triathlon is using an aero bar, which is giving the main aero advantage, and also able to maintain an aero optimized position. Most bike riders can't and most are not in an "aero" optimized position.

Thus, I would hypothesize that the average Joe gets more from "aero" bike parts than a professional.

[Talrand]

Originally Posted by Mark McM

[..]
The industry stopped pushing the UCI to reduce the weight limit, and there's even some indication that they actually petitioned the UCI NOT to reduce the weight limit.

What is this indication?

[martl]

Originally Posted by Talrand

What is this indication?

The past couple of years made it clear they can make the whole biking community ditch their perfectly good stuff for new stuff by just bull****ting about"marginal gains" in aero, chain friction, oversized pulleys and other snake oil, so why push on the weight side which would actually require serious effort on their side?

[KonaSS]

the constant yelling at clouds is too much sometimes

[El Chaba]

Originally Posted by cash05458

Which is kinda funny considering this same industry told us for about 20 years that the most important thing was weight...and had plenty of "studies" to prove that fact.

I don't know but after 40 years of riding and hearing all the "latest" hype things forever and I could go thru a long list...I could really care less about marginal gains at 60 years old.

Your cycling career and mine parallel one another. You no doubt recall that for years every development was touted in terms of how much time you would save in a 40 km time trial. For a number of those years I kept a tally, and had I implemented all of them I would have finished 5 minutes before my start time, assuming a 60 minute pace….The “industry” has no credibility, and they did it to themselves….

[Dude]

Originally Posted by KonaSS

the constant yelling at clouds is too much sometimes

1000% yes, dawg.