Why are tubular wheels so narrow?
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Nope, you're wrong.
You don't even have to measure the inflated tire with calipers and do the math on that one. For the inflated size, the max tire for aero even quoted by HED themselves on their 25mm outer width wheels is 25mm tires.
See TMonk's reply. He and I both know the answer to this.
The real answer is that you have to buy, install, inflate and measure it. Then if you really care, do the field testing on it. The fast math is that you need a tire size likely maximum of the outer width of the aero rim. 25mm outer, 25mm max tire. HED have stated routinely 25mm is fine on the 25mm wheels BUT that 23mm is still optimal, if you care. I've got old chats with Andy at HED about this.
The "why" is that all the used wheels being looked at are the older narrower ones when folks were running 19mm, 21mm, maybe 23mm tubulars. They DO make modern width tubulars. Like the HED Stinger lineup. The old HED 3 was meant for a 19mm tubular. I owned one that came with a 21mm on it and I measured it inflated way past "105". The 19mm inflated fully was even at "100".
You don't even have to measure the inflated tire with calipers and do the math on that one. For the inflated size, the max tire for aero even quoted by HED themselves on their 25mm outer width wheels is 25mm tires.
See TMonk's reply. He and I both know the answer to this.
The real answer is that you have to buy, install, inflate and measure it. Then if you really care, do the field testing on it. The fast math is that you need a tire size likely maximum of the outer width of the aero rim. 25mm outer, 25mm max tire. HED have stated routinely 25mm is fine on the 25mm wheels BUT that 23mm is still optimal, if you care. I've got old chats with Andy at HED about this.
The "why" is that all the used wheels being looked at are the older narrower ones when folks were running 19mm, 21mm, maybe 23mm tubulars. They DO make modern width tubulars. Like the HED Stinger lineup. The old HED 3 was meant for a 19mm tubular. I owned one that came with a 21mm on it and I measured it inflated way past "105". The 19mm inflated fully was even at "100".
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How much aero loss would there be running a 25 mm tubie on a 27 mm rim compared to the same setup with clinchers or tubeless? Has anyone measured or seen any wind tunnel data (CdA change)? I have measured 25 mm clincher vs 23 mm at 30 mph and the difference for a TTer is not insignificant.
(I am considering going back to tubies)
(I am considering going back to tubies)
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Smaller tires on wider wheels still get more air volume than a small tire on narrow wheels. The rim bed has more volume. So, it's likely not necessary to worry about putting the largest tire on modern width rims as it used to be with narrower rims. So for aero wheels 25mm outer width, if you ran a 25 on a 23mm or 21mm rim........perhaps can run a 23mm on the 25mm rim given the volume change in the rim bed. (Disclaimer, the rim bed volume chat is me theorizing.)
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For some context, I am new to the world of (I)TT. Ironically enough, I've been training for (and winning) TTT events since 2019 when I was recruited by another teammate on the elite road team who is an excellent time trialist. We've won states/district (SCNCA) champs, set course records on local series (Fiesta Island FITT)) and now I'm starting to optimize for ITT. The aero stuff of course matters in TTT but things like drafting execution, rotation "choreography" and the like play a bigger role.
I just rode my first 20k at the local series and I'm looking at it as sort of a benchmark. It was a sloppy ride, but I'm happy with my power and looking forward to setting a better time on the next one in April!. It's a different headspace, ITT vs TTT.At this risk of sounding argumentative, I think that aero in the context of this discussion does matter for an armature racer in a time trial. Is there anything on the line? No, but it is gratifying to see improvements. For example, my TTT captain and road teammate just beat his own course record at our local TT (FITT) on 30 less watts than his previous record. He has a 9 month old (child 2) and his training has suffered significantly, however he has not stopped making improvements to his position and equipment. I mean, that's pretty damn cool. He's looking to get fitter later in the year and go sub 50 minutes for the 40k.
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Yes. I raced before anybody talked of wheel weights but we all knew our rim weights (or at least the published weights). I raced rims that were 290 grams and lighter. Tires of 250 grams and lighter. Laced my rims with the equivalent of 1.8/1.5 spokes. The place that really paid was when the wheel you HAD to get on was passing you. A blessing every time you came out of a corner or the pack surged.
I picked up a disc wheel at REI a couple decades ago. It was HEAVY. I wondered if cyclists had lost their minds. I always trained on heavier wheels and raced on lighter ones. The difference is profound.
My Scheeren Weltmeister tubular front wheel with a 240g sew-up is still 2 oz. lighter than my carbon front clincher wheel/tube/tire setup. I haven't ridden the carbon ones yet, and to be fair, I should mention that they are 130kg rated. Light weight counts more than aero in my book, especially for wheels. So does durability.
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as noted (PSIMET) , you're getting into rarified air with tubulars, especially carbon tubulars (are there any other kind these days ?)
specialized, racing stuff... PITA for most...
HED Stinger 3 tubulars are 35mm external, and 27mm on the tire cradle. 'Toroidal', so not 'deep'. I'm sure there are good TT race profile rims/wheels available for your use, in varied profiles, for only a few ounces of gold...
as usual, BF, and this thread, has a high Noise to signal ratio...
There's a lot more to 'aero' than just 'profile'; and if you're aero need is absolute, then EVERYTHING matters.
and if you just love the ride of tubulars and are willing to put up with the complications - they're still great riding gear.
google "Tom Anhalt' (Blather 'bout Bikes) or Hambini and 'aero' and you'll find plenty of good info, some contention, but overall better opinion and research than you'll find on BF.
Ride On
Yuri
specialized, racing stuff... PITA for most...
HED Stinger 3 tubulars are 35mm external, and 27mm on the tire cradle. 'Toroidal', so not 'deep'. I'm sure there are good TT race profile rims/wheels available for your use, in varied profiles, for only a few ounces of gold...
as usual, BF, and this thread, has a high Noise to signal ratio...
There's a lot more to 'aero' than just 'profile'; and if you're aero need is absolute, then EVERYTHING matters.
and if you just love the ride of tubulars and are willing to put up with the complications - they're still great riding gear.
google "Tom Anhalt' (Blather 'bout Bikes) or Hambini and 'aero' and you'll find plenty of good info, some contention, but overall better opinion and research than you'll find on BF.
Ride On
Yuri
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as noted (PSIMET) , you're getting into rarified air with tubulars, especially carbon tubulars (are there any other kind these days ?)
specialized, racing stuff... PITA for most...
HED Stinger 3 tubulars are 35mm external, and 27mm on the tire cradle. 'Toroidal', so not 'deep'. I'm sure there are good TT race profile rims/wheels available for your use, in varied profiles, for only a few ounces of gold...
as usual, BF, and this thread, has a high Noise to signal ratio...
There's a lot more to 'aero' than just 'profile'; and if you're aero need is absolute, then EVERYTHING matters.
and if you just love the ride of tubulars and are willing to put up with the complications - they're still great riding gear.
google "Tom Anhalt' (Blather 'bout Bikes) or Hambini and 'aero' and you'll find plenty of good info, some contention, but overall better opinion and research than you'll find on BF.
Ride On
Yuri
specialized, racing stuff... PITA for most...
HED Stinger 3 tubulars are 35mm external, and 27mm on the tire cradle. 'Toroidal', so not 'deep'. I'm sure there are good TT race profile rims/wheels available for your use, in varied profiles, for only a few ounces of gold...
as usual, BF, and this thread, has a high Noise to signal ratio...
There's a lot more to 'aero' than just 'profile'; and if you're aero need is absolute, then EVERYTHING matters.
and if you just love the ride of tubulars and are willing to put up with the complications - they're still great riding gear.
google "Tom Anhalt' (Blather 'bout Bikes) or Hambini and 'aero' and you'll find plenty of good info, some contention, but overall better opinion and research than you'll find on BF.
Ride On
Yuri
The Stinger 3s are 26mm wide. They had a wider CX model, but I doubt the 35mm width- have you actually seen this?
In any case ludicrous on the same line with "TT race profile".
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as noted (PSIMET) , you're getting into rarified air with tubulars, especially carbon tubulars (are there any other kind these days ?)
specialized, racing stuff... PITA for most...
HED Stinger 3 tubulars are 35mm external, and 27mm on the tire cradle. 'Toroidal', so not 'deep'. I'm sure there are good TT race profile rims/wheels available for your use, in varied profiles, for only a few ounces of gold...
as usual, BF, and this thread, has a high Noise to signal ratio...
There's a lot more to 'aero' than just 'profile'; and if you're aero need is absolute, then EVERYTHING matters.
and if you just love the ride of tubulars and are willing to put up with the complications - they're still great riding gear.
google "Tom Anhalt' (Blather 'bout Bikes) or Hambini and 'aero' and you'll find plenty of good info, some contention, but overall better opinion and research than you'll find on BF.
Ride On
Yuri
specialized, racing stuff... PITA for most...
HED Stinger 3 tubulars are 35mm external, and 27mm on the tire cradle. 'Toroidal', so not 'deep'. I'm sure there are good TT race profile rims/wheels available for your use, in varied profiles, for only a few ounces of gold...
as usual, BF, and this thread, has a high Noise to signal ratio...
There's a lot more to 'aero' than just 'profile'; and if you're aero need is absolute, then EVERYTHING matters.
and if you just love the ride of tubulars and are willing to put up with the complications - they're still great riding gear.
google "Tom Anhalt' (Blather 'bout Bikes) or Hambini and 'aero' and you'll find plenty of good info, some contention, but overall better opinion and research than you'll find on BF.
Ride On
Yuri
Aero testing is very, very time consuming. Yes, you are correct. There is much, much more to it. Lot of work. Although it took over one year, I managed to lower my CdA from 0.205 to just under 0.150 ^m2.
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At this risk of sounding argumentative, I think that aero in the context of this discussion does matter for an armature racer in a time trial. Is there anything on the line? No, but it is gratifying to see improvements. For example, my TTT captain and road teammate just beat his own course record at our local TT (FITT) on 30 less watts than his previous record. He has a 9 month old (child 2) and his training has suffered significantly, however he has not stopped making improvements to his position and equipment. I mean, that's pretty damn cool. He's looking to get fitter later in the year and go sub 50 minutes for the 40k.
It's just aero was so played out for so many years in crits and just enthusiast riding. I'd watch rider after rider pontificate about their aero gains and the "latest" completely biased and flawed research they believe they saw only to watch them fade off the back. I just am jaded.
Sure there's a baseline that needs to be covered. I dropped riding 36mm wheels last year and built up a new set of 55's for myself. Went against my instincts because it added what I felt was a substantial amount of weight to the set. But "gotta run what we offer" won out. Getting back to group ride speeds and feeling the tiny difference in all sorts of little spots around a ride I've been riding for a long time reminded me that while they won't fix my complete lack of ability and talent they are still al lot of fun to ride.
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With clinchers, the shape of the tire is very much influenced by the rim width; you need fatter tires and rims to not only maintain the tire shape, but to prevent pinch flats. Again, you don't get pinch flats on tubulars. You can ride them at irresponsibly low pressure and have little risk of pinch flatting or even damaging the rims.
So, yeah.
Last edited by rubiksoval; 01-15-22 at 03:55 PM.
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Your points regarding acceleration are spot on.
I picked up a disc wheel at REI a couple decades ago. It was HEAVY. I wondered if cyclists had lost their minds. I always trained on heavier wheels and raced on lighter ones. The difference is profound.
My Scheeren Weltmeister tubular front wheel with a 240g sew-up is still 2 oz. lighter than my carbon front clincher wheel/tube/tire setup. I haven't ridden the carbon ones yet, and to be fair, I should mention that they are 130kg rated. Light weight counts more than aero in my book, especially for wheels. So does durability.
I picked up a disc wheel at REI a couple decades ago. It was HEAVY. I wondered if cyclists had lost their minds. I always trained on heavier wheels and raced on lighter ones. The difference is profound.
My Scheeren Weltmeister tubular front wheel with a 240g sew-up is still 2 oz. lighter than my carbon front clincher wheel/tube/tire setup. I haven't ridden the carbon ones yet, and to be fair, I should mention that they are 130kg rated. Light weight counts more than aero in my book, especially for wheels. So does durability.
#39
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I have killed more clincher rims, as when you ding the fragile 'hooks' required to hold the clincher tire on, it's game over.
Again, the tubular rim profile is superior as it is stronger, lighter, and highly resistant to impacts and pinch flats. Plus the rim is isolated from tire inflation pressures. The only advantages for clinchers is lower cost and easier to install tires. But there is no performance overlap.
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#41
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Some people have to learn the hard way what a PITA tubulars are. I've switched to tubeless. I have some 19mm internal width hooked rims and some 23mm internal width hookless rims. The hookless rims made tire installation incredibly easy. Even a 180 lb rider can use them with 25mm tires, but the 27mm external width is allegedly optimized for 28mm tires.
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I was pleasantly surprised to learn that, with the advent of tubular rim tape instead of glue, removable Presta valve cores, and Stan's tire sealant, sew-ups are as nearly as convenient as clinchers these days. Hopefully they'll come back into fashion, like records! It would be nice to have a better selection, and maybe some larger sizes.
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Not wanting to put words in his mouth but I know from his (rubiksoval) previous posts he is a Cat 1 rider and has been racing for many years so would be faster and have more racing experience than just about anyone else on this forum.
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I have killed more clincher rims, as when you ding the fragile 'hooks' required to hold the clincher tire on, it's game over.
Again, the tubular rim profile is superior as it is stronger, lighter, and highly resistant to impacts and pinch flats. Plus the rim is isolated from tire inflation pressures. The only advantages for clinchers is lower cost and easier to install tires. But there is no performance overlap.
On the road, give me a very fast clincher/latex setup any day over a fast tubular setup. I'll take the Vittoria Corsa Speeds with latex tubes on my 45mm carbon clinchers over Vittora Corsa Speed tubulars on my Hed Stinger 4s. For those two setups, the clinchers are as fast/ faster AND no need to put 8 layers of glue on the tubular to try to bring the CRR even.
I always gravitated towards tubulars earlier on because they were just so much lighter than the clinchers. But the last 5-6 years have really closed that gap significantly, and, it turns out, weight just doesn't actually matter that much when it comes to speed.
I have a tubular disc wheel I bought pretty cheaply last year, but I'm constantly lamenting buying it instead of just getting a clincher one. I have a Corsa Speed on it but am worried about the puncture protection over a much longer race I have coming up so will probably get a Corsa 2.0...ehhhh. Don't particularly want to glue and reglue. Maybe a good case for a new bike with disc wheels?!
Last edited by rubiksoval; 01-17-22 at 06:21 AM.
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Yes! I love crits. It's pretty much all my racing is centered around. The more technical the course, the more my enjoyment (and benefit compared to those with significantly more watts to spare).
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#47
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Ugh... FFS guys - wheel company here: people break both types of rims.
As for which one is stronger? Tubular. No question about it. Not even close. Tubular is stronger and more durable. You're also more likely to finish a ride on a cracked tubular than a cracked tubeless wheel. The reality is that even with a cracked rim on a tubular if your tire is fine then you can keep running it. I've seen rims with small cracks in them run a whole season of racing.
Tubular as a technology is still by far the best for cross. 2 things always stick in my mind: Sven Nys telling us, "I start at 1 bar and go down from there" when asked what pressure he ran and Katie Compton coming through the pits at nationals and telling mark "9". She meant PSI. She won. Tubeless doesn't work in those situations so those running tubeless must run at higher pressures. Running at higher pressures and using stiffer tires puts them as a great disadvantage.
Yay. No one here cares about that though. Road tubular? Sure. Whatever. I have stacks of rims sitting here if anyone wants to ever build anything again. Until then I will keep building them for track and cross.
If you don't understand tubular or think it's time is done then this thread isn't really for you anyway.
As for which one is stronger? Tubular. No question about it. Not even close. Tubular is stronger and more durable. You're also more likely to finish a ride on a cracked tubular than a cracked tubeless wheel. The reality is that even with a cracked rim on a tubular if your tire is fine then you can keep running it. I've seen rims with small cracks in them run a whole season of racing.
Tubular as a technology is still by far the best for cross. 2 things always stick in my mind: Sven Nys telling us, "I start at 1 bar and go down from there" when asked what pressure he ran and Katie Compton coming through the pits at nationals and telling mark "9". She meant PSI. She won. Tubeless doesn't work in those situations so those running tubeless must run at higher pressures. Running at higher pressures and using stiffer tires puts them as a great disadvantage.
Yay. No one here cares about that though. Road tubular? Sure. Whatever. I have stacks of rims sitting here if anyone wants to ever build anything again. Until then I will keep building them for track and cross.
If you don't understand tubular or think it's time is done then this thread isn't really for you anyway.
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#48
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Aero rims are important if you are a professional rider doing time trials but for everyone else the air drag is provided by the rider. Few bikes even have aero bars and this is the best place to start if one truly wants to reduce air drag. Pro racers realized quite some time ago that going from 23mm to 28mm tires had no discernible impact on rolling resistance but did smooth out the ride and in some cases the much lower tire pressures provided for less rolling resistance with the tire better able to roll over bumps in the road.
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Pro racers realized quite some time ago that going from 23mm to 28mm tires had no discernible impact on rolling resistance but did smooth out the ride and in some cases the much lower tire pressures provided for less rolling resistance with the tire better able to roll over bumps in the road.