Challenge Grifo XS Tubular Tire for Cyclocross
The Challenge Grifo XS tubular tire is a premium hand-made tubular cyclocross racing tire for 26" or 29" wheels.
This is the tire I used for summer riding in the San Francisco Bay Area; it is an excellent choice, but once the tread edges come off with use, grip (“bite”) declines, and in mud there’s no grip.
See Challenge Grifo XS tubular tire @AMAZON pricing at Amazon.
Ride quality
On my Moots Psychlo X RSL, ride quality is excellent. I tend to run 55-60 PSI while ascending, then drop the pressure to 40-45 PSI for the descent (my riding requires some pavement to approch the dirt roads and trails I ride, so higher pressure is preferable for those portions).
I prefer the 34C size in this tread and tire; my rear 34C variant saw perhaps 800 miles. However, I have given up on the 34C size in front, as three front tires quickly developed an awful bulge problem.
Technical features
Oddly, the picture on the Challenge site shows 300 TPI, but the tires I bought are actually 260 TPI, which is also what the specifications say.
Use: Cyclocross Size: 28" Width: 32mm Weight: 415 gr (nominal) TPI: 260 BAR: 2-6 PSI: 28-87 Bead Casing: Super Poly Color: Black-Brown
Weight
As actually weighed for Grifo 32 XS.
386 grams (Grifo XS 32 tubular)
(29g LESS than nominal weight).
As actually weighed for Grifo 34 XS.
409g, 418g (Grifo XS 34 tubular)
The 2012 tire is now a Grifo 33 XS, so this tire might be a prior model.