[anden]

From www.velonews.com/tech/report/articles/6524.0.html: "The Scale CR1 Limited is Scott's all-carbon XC hardtail. This is Frishy's bike of choice for the lightning-fast Athens XC course. His race bike weighed close to 20 pounds and came equipped with a rear custom Dugast tubular mountain bike tire mounted to a very trick carbon 650C triathlon rim."

650c (ISO 571) is much closer to 26" (559) than to 29" (622), but is there a market for another wheelsize, between 26" and 29"? Perhaps for those who recognize drawbacks with their 26" wheels but get into problem with handlebar height and toe overlap with 29". Let's say typical rider heights between 5'3 and 5'8?

 

[Guitar Ted]

Over-all Circumferance?

I wonder what Frichey's Dugast has for an outer circumferance? Perhaps he has a set-up that yeilds the over-all same dimensions as a 26" rim, mounted with 1.95 tires? So, really he may only be getting lighter weight, with less pinch flatting, (because of the tubular tire) . He better not flat during the race, or his medal chances will be gone!

 

[bulC]

why

I wonder what Frichey's Dugast has for an outer circumferance? Perhaps he has a set-up that yeilds the over-all same dimensions as a 26" rim, mounted with 1.95 tires? So, really he may only be getting lighter weight, with less pinch flatting, (because of the tubular tire) . He better not flat during the race, or his medal chances will be gone!

he's not using 650s because of any size difference, but because knobby tubulars are available in that size. In the late 80s Gary Fisher had Vittoria make up some 26" knobby sewups, which rode very nicely.

 

[Cloxxki]

His Dugast tubulars are brandnew, believe me. He could get them in any size he'd spec, it's rims that are a bit harder to persuade manufacturers to do in a custom size.

For small riders that have toe overlap with a 29", no matter how you trick the geometry, or can't get the tricked geometry to work for their type of riding, 26"as-is, is just fine, and has been for decades. 650c is only an advantage for riders that want both tubulars and use a 26"-designed frame, as it fits, by chance.
Any advantage for the 650c Dugasts is that Frischi can have tires that look a bit like Ritcheys, but aren't as bad as usual. Compared to his competition on Nokian NBX Lite's and Schwalbe Racing Ralphs on latex tubless sytems, I don't expect his setup to be any faster, if not much slower, as well as heavier.

If you're going to use narrow Triathlon tubulars, 650c for an adult man over 5'4" doesn't make much sence to me. Why, if rolling resistance is obviously your main objective, would you say no to the 8-9% lower resistance 700c tubular would offer you? I seem to recall Ksyrium Tubulars to have wider tubular rims, which should help with MTB sized tubulars.

Frischi, being a veteran Eclipse racer and tester, will be sure to us a nice splash of latex in his freak tires. I know a Dutch rider flatting a similar setup with a Racing Ralph tread out of the lead of a National XC race, I guess he was trying to run them dry, but he's reported to really like their performance. Then again, aren't RR's really fast to start with, do they even need the tubular trick to be fast, when latex is so well proven lately?

 

[erikh]

is this it?

nicked off a Dutch MTB forum, allegedly Thomas Frishknecht's (=Frishi? ) bike:

 

[Cloxxki]

Yeah, see also a thread I started over on the weight forum.