Why carbon rims?

[Dave]

The current advertised weight of a BTLOS WARL44 wheelset with extra light rims and DT240 hubs is 1375 grams and $1262. With Bitex hubs the weight goes up by 25 grams and the price drops to $866, plus $110 for shipping, unless you have a free shipping code.

https://btlos.com/all-road-hookless-...arbon-wheelset

I have a set of WARL29 extra light wheels with Bitex hubs that weighs 1335.

[NHAero]

Originally Posted by RoosterCogset

Aren't you worried about where they left out the 25g of material?

He got the hollow spokes

[thwart]

Originally Posted by El Chaba

Data point: Nobody can drop me on the local group ride when I am using box section tubular wheels. Many of these wheelsets are twenty years old and sometimes as old as forty years. It really doesn’t matter to me what the pros are using or how many watts I am “giving up” or whatever. I understand that my findings are in contradiction to what the industry and its adherents are pushing. I would write that I don’t care, but that is not true…It gives me a great deal of satisfaction.

Like button pushed.

[prototoast]

Originally Posted by NHAero

I've been on carbon disc wheels less than 3 years on my all road bikes. What I've noticed, vs. the alloy disc wheels on my FS29er and old 26er, is that even though the wheels are lighter and lower spoke count, they are still true. And they've taken some real hits. Now for the first time I have some lightweight rim brake carbon wheels (thanks to Clean39T) and it will be interesting to see how they fare. I have to say the sound the pads make (Swissstop) when braking isn't lovely, it makes me think they're scratching up the rim, but when I look everything looks fine.

This is consistent with my experience. I'm heavy for a cyclist, average for an American, and with aluminum rims, I used to break spokes all the time and wheels needed frequent truing. The frequency of both has been substantially lower with carbon rims.

[KonaSS]

Originally Posted by El Chaba

Data point: Nobody can drop me on the local group ride when I am using box section tubular wheels. Many of these wheelsets are twenty years old and sometimes as old as forty years. It really doesn’t matter to me what the pros are using or how many watts I am “giving up” or whatever. I understand that my findings are in contradiction to what the industry and its adherents are pushing. I would write that I don’t care, but that is not true…It gives me a great deal of satisfaction.

This tells us nothing. Maybe your group rides are not very fast/long. Maybe you are very fast compared to your friends. Maybe you all ride similar bikes. Find a fast enough group ride where it makes a difference and let us know if your decreased satisfaction leads to increased interest in modern technology.

[benb]

Originally Posted by KonaSS

This tells us nothing. Maybe your group rides are not very fast/long. Maybe you are very fast compared to your friends. Maybe you all ride similar bikes. Find a fast enough group ride where it makes a difference and let us know if your decreased satisfaction leads to increased interest in modern technology.

No it's probably just that he's in the peloton and the energy savings of being in the pack absolutely dwarf all these equipment gains. The entire thing with experience.

The watt #s always seem to get molded into something that effects recreational riders in all regimes of riding when even the marketing data is talking about an elite rider doing 25-30mph solo in the wind in a breakaway or TT.

I'm sure this is region specific but around here 99% of the time if someone gets dropped it's uphill. The pack might be going 30mph on the flat but if you know what you're doing riding in the pack you save 10x what any of this gear saves you. But when you hit a big hill none of that matters, if the group accelerates and your power:weight isn't there you burn matches. Repeat until you blow up and get dropped.

It always eventually comes back to me how dumb all this is at the recreational level compared to racing as the recreational rides have absolutely no clue what they're doing these days in terms of staying out of the wind and running a paceline.

[MikeD]

Originally Posted by prototoast

This is consistent with my experience. I'm heavy for a cyclist, average for an American, and with aluminum rims, I used to break spokes all the time and wheels needed frequent truing. The frequency of both has been substantially lower with carbon rims.

Breaking spokes and truing doesn't have much to do with the rim. The quality of the spokes and the wheel build are what's important.

[benb]

Yep.

99% of the time for me it was the builder.

I have had multiple wheelsets that were incredibly similar built by different people, the wheels built by the expert builder were bombproof and the wheels built by the LBS guy who kind of knew what he was doing had issues.

I would expect this is completely independent of materials. If the carbon wheels are not built correctly good luck. Maybe shorter spokes and stronger rims makes them more tolerant of build mistakes though.

[KonaSS]

Originally Posted by benb

I'm sure this is region specific but around here 99% of the time if someone gets dropped it's uphill. The pack might be going 30mph on the flat but if you know what you're doing riding in the pack you save 10x what any of this gear saves you. But when you hit a big hill none of that matters, if the group accelerates and your power:weight isn't there you burn matches. Repeat until you blow up and get dropped.

It always eventually comes back to me how dumb all this is at the recreational level compared to racing as the recreational rides have absolutely no clue what they're doing these days in terms of staying out of the wind and running a paceline.

Well, I race. It certainly is recreation racing (and training, and group rides) and the thing that everyone who wants to dismiss aero says is that it only applies in some solo move at above 25mph. But really, it helps you the entire ride. Like every. single. second. You are saving watts in the draft, in the front, at 15 mph and at 25 mph. So you can save watts and be fresher for those hills and maybe you don't get popped. Races are about what happens when everyone starts to get tired.

If I can save an average of 10 watts over a 3 hour race - the difference between averaging 250watts versus 240watts for the same speed over 3 hours is very big. So if you race, and you're my competitor, I very much encourage to continue this line of thinking that it is dumb and doesn't matter, I think that is great. Keep spreading the misinformation.

[MikeD]

Originally Posted by KonaSS

Well, I race. It certainly is recreation racing (and training, and group rides) and the thing that everyone who wants to dismiss aero says is that it only applies in some solo move at above 25mph. But really, it helps you the entire ride. Like every. single. second. You are saving watts in the draft, in the front, at 15 mph and at 25 mph. So you can save watts and be fresher for those hills and maybe you don't get popped. Races are about what happens when everyone starts to get tired.

If I can save an average of 10 watts over a 3 hour race - the difference between averaging 250watts versus 240watts for the same speed over 3 hours is very big. So if you race, and you're my competitor, I very much encourage to continue this line of thinking that it is dumb and doesn't matter, I think that is great. Keep spreading the misinformation.

How many of us race? Stability in crosswinds and lightness are more important to me. I used to use aerobars. They are more aero than wheels. I don't use them any more.

[Mark McM]

Originally Posted by NHAero

I've been on carbon disc wheels less than 3 years on my all road bikes. What I've noticed, vs. the alloy disc wheels on my FS29er and old 26er, is that even though the wheels are lighter and lower spoke count, they are still true. And they've taken some real hits.

I've also noticed that among aluminum rims, the deeper the rim the less likely it is to go out of true. Which is probably not surprising, as increasing the depth of a rim increases its strength and stiffness (out of proportion with its weight).
I've got several sets of 30+ mm deep aluminum rims that have never had to be trued after many years of hard use. Carbon rims tend to be deeper than aluminum rims, so I wonder if robustness is more closely tied to depth or material.

[prototoast]

Originally Posted by MikeD

How many of us race? Stability in crosswinds and lightness are more important to me. I used to use aerobars. They are more aero than wheels. I don't use them any more.

You can use whatever wheels make the most sense for you. Nobody here telling you not to use aluminum rims. You ask what the benefits of carbon rims are, you got a bunch of answers. If those characteristics aren't important to you, you can continue using aluminum rims and be happy about that. Lots of other people use carbon rims and are happy with those. It's completely fine for us to have different preferences.

[prototoast]

Originally Posted by Mark McM

I've also noticed that among aluminum rims, the deeper the rim the less likely it is to go out of true. Which is probably not surprising, as increasing the depth of a rim increases its strength and stiffness (out of proportion with its weight).
I've got several sets of 30+ mm deep aluminum rims that have never had to be trued after many years of hard use. Carbon rims tend to be deeper than aluminum rims, so I wonder if robustness is more closely tied to depth or material.

Deeper wheels tend to be stiffer, and stiffer wheels flex lass, which puts less strain on the spokes, helping them keep true.

Carbon rims also have the advantage that coming out of a mold, they tend to be flatter than aluminum rims before they are laced up, which makes it easier to build them up with even spoke tension which again helps keep them true.

[benb]

Originally Posted by KonaSS

Well, I race. It certainly is recreation racing (and training, and group rides) and the thing that everyone who wants to dismiss aero says is that it only applies in some solo move at above 25mph. But really, it helps you the entire ride. Like every. single. second. You are saving watts in the draft, in the front, at 15 mph and at 25 mph. So you can save watts and be fresher for those hills and maybe you don't get popped. Races are about what happens when everyone starts to get tired.

If I can save an average of 10 watts over a 3 hour race - the difference between averaging 250watts versus 240watts for the same speed over 3 hours is very big. So if you race, and you're my competitor, I very much encourage to continue this line of thinking that it is dumb and doesn't matter, I think that is great. Keep spreading the misinformation.

How do you do the math to get to 10W average over the course of the race if the wind tunnels says 10W at 25mph with no one around you (or no rider on the bike, or the wheel is not even on the bike) but it turns out in the race you are drafting someone 80% of the time?

If you're tall enough to have your head stick it up it would seem the helmet is the thing that is relevant in all situations.

I would love to see any aero data that tested rider A behind rider B or in a group of 10 riders. We know the rider nestled in the pack could be saving way over 100w, it probably makes most of the equipment choices irrelevant till that rider is exposed to the wind. I know from my own racing experience there was tons of time I was in like zone 1 in the pack doing 30mph on the flats. It's a HUGE effect.

I am not saying this stuff doesn't matter in a race. But to someone going "I don't get dropped out of the pack in a recreational ride" that effect of drafting negating all this is probably highly relevant.

One thing I do get is a ton of the marketing is about convincing people who don't race that their needs are exactly the same as people who do race. I like to go fast even though I am 100% done with racing and have no real desire to do it again, but there are all kinds of things where the cost or PITA of something that matters for racing is a step too far if you don't race. Especially when you're time crunched and/or spending time on those things has to come out of your riding time. (Not saying any particular wheel is a time suck, but other things are.)

[MikeD]

Originally Posted by prototoast

You can use whatever wheels make the most sense for you. Nobody here telling you not to use aluminum rims. You ask what the benefits of carbon rims are, you got a bunch of answers. If those characteristics aren't important to you, you can continue using aluminum rims and be happy about that. Lots of other people use carbon rims and are happy with those. It's completely fine for us to have different preferences.

In that response, I wasn't commenting on carbon vs. aluminum, but aero vs. non-aero. Aero rims are built with both materials.