I know it’s often conventional wisdom to fit a wider tyre on the rear wheel, but I was tempted to reverse this.
My race wheels are usually an 808 FC tubular up front (21mm Tangente from previous wheel) and a Zipp 900 on the back (21mm Tangente). Now, the 21mm tub on the disc sits nicely and anything wider would protrude more than the 21mm thick disc. However, the 21mm looks very lost on the 808 FC, and although I’ve read somewhere that this tyre is still optimal on this rim, I was thinking about putting a 23mm on there for a more compliant ride (this will still look lost I’m sure).
You’re probably better off running a 23 up front. In my experience, it will handle better and that rim will be better when paired with a 23. Anyway, it definitely won’t be a problem.
On the wide rims, a 23 is nearly as good aerodynamically except at 0 yaw, but at low yaw you are often splitting hairs anyway, even a disc saves you little at low yaw. A wider tire rolls better, handles better and rides better.
All true but the Schwalbe Ironman is super fast from a Crr standpoint and, in my experience, has excellent flat protection for such a fast tire.
IMO, for a tubular race tire, it’s tough to beat unless you go up to 24mm at which point I’d eye the new Specialized SWorks Turbo for the rear.
Does the Schwable handle very well? I thought about riding them for road racing and crits, but I didn’t know if they use a harder compound for a lower Crr.
All true but the Schwalbe Ironman is super fast from a Crr standpoint and, in my experience, has excellent flat protection for such a fast tire.
IMO, for a tubular race tire, it’s tough to beat unless you go up to 24mm at which point I’d eye the new Specialized SWorks Turbo for the rear.
Does the Schwable handle very well? I thought about riding them for road racing and crits, but I didn’t know if they use a harder compound for a lower Crr.
I wouldn’t say it’s “harder” by any means. To the touch (totally subjective) it feels slightly softer than a GP4000s. That said I never had cause to test the handling limits of the tire: just rode it in a few Olys and one 70.3. With that said, in a road racing scenario I’d probably want something wider like the above-mentioned Specialized tire. Whatever aero penalty you suffer will probably be more-than compensated for by its handling. Crr between the two should be close enough to not sweat it. If you run clinchers you can use the Specialized Turbo Cotton which is, apparently, very fast and very grippy.
Yes, still going strong since 2009! The front still has loads of tread on it. You seem to be inferring it’s a bad tyre? Are the newer ones that much better, as I thought the original was basically a Corsa Evo with thicker tread/rubber?
The old Tangente requires about 11-12 watts more per pair (Wow!) than the Schwalbe Ironman 22mm or the new Tangente SLSpeed 24mm. Here’s data from Tom Anhalt’s site:
I picked up a couple of the new Tangente 24mm a few weeks ago and I have a Schwalbe Ironman on order for the front. I gotta say, I’m pretty psyched to be back on tubies!
Look into the new Tangentes of course, and also the Schwalbe Ironman tubular.
Yes, still going strong since 2009! The front still has loads of tread on it. You seem to be inferring it’s a bad tyre? Are the newer ones that much better, as I thought the original was basically a Corsa Evo with thicker tread/rubber?
like Jack has said, you’re looking at the problem wrong.
your problem is: “what are the best tubulars for my wheels” and not necessarily “what is the best tire width for my wheels”
first of all, front tire. you want narrow AND fast rolling AND magic aero properties at yaw. There is only one at this point, Schwalbe IM Tubular 22mm, whose magic aero properties are assumed, not tested. But that said it’s narrow and rolls very well, so two of three.
next rear. narrower is faster aerodynamically, but rolling resistance is a huge component, especially since your disc is shielded. You can’t go wrong with another Schwalbe 22mm tubular, but you might even consider a wider, faster rolling tire, like the new tubulars from Zipp. Their 27mm tubular is VERY fast, and likely mates very well to a Super9 disc, which you don’t have.
I know it’s often conventional wisdom to fit a wider tyre on the rear wheel, but I was tempted to reverse this.
My race wheels are usually an 808 FC tubular up front (21mm Tangente from previous wheel) and a Zipp 900 on the back (21mm Tangente). Now, the 21mm tub on the disc sits nicely and anything wider would protrude more than the 21mm thick disc. However, the 21mm looks very lost on the 808 FC, and although I’ve read somewhere that this tyre is still optimal on this rim, I was thinking about putting a 23mm on there for a more compliant ride (this will still look lost I’m sure).
not a toss-up for the front wheel. Schwalbe 22mm. Not until we get some aero data from Zipp at least.
for the rear I’d go 24mm tubular unless you get a Super9 (or other wide-rim) disc and then I’d go 27, which is the fastest tire out there in terms of Crr.
I’m trying to come up with a rule of thumb for drag per mm of tire width, sort of percolating some of Andy Coggan’s “a, b, c” tire work and a few Zipp/Continental and FLO charts I’ve seen. I’m thinking it’s 2 watts/mm of tire of aero drag. Based on Tom A’s charts, I’d say that it’s an equal amount of Crr, so there goes my rule of thumb
Thanks guys. I guess it’s a toss-up between the Schwalbe Ironman and the 24mm SL Speeds.
It’s interesting to note that the newer Zipp SLS is as fast or faster than the previous Tangente, even without those amazing dimples
Yes, I read that the original Tangente 21mm tyre was a good (aero) choice for the FC rim. It just seems counter-intuitive that a tyre 4-5mm narrower than the rim would be faster, as it leaves a big ‘lip’ either side of the tyre where the air hits the brake-track. So is the principle (presumably) that a wider front tyre will shunt the air wide of the rim, which will create more turbulence than if it is ‘guided’ by the FC rim profile?
What I was getting at, is that the narrower the tyre, the more rim you see with a FC. If you stuck a 22mm tyre on a 900 disc for example - you wouldn’t see any rim, as it would be shielded by the tyre.
