Up for sale is a set of Challenge Grifo XS file treads in size 32. Used a few times in the early season of 2009 then pulled off to mount mud tires on the rims. I believe they were ridden in about 6-8 races
for a total of about 4-5 hours, and none in the mud. I fully washed the wheels and tires after
each race so they are in fantastic shape - essentially no wear. They've been stored in a wheel bag since so no exposure to light.
Even though they're a dry conditions tire I still applied a layer of AquaSeal to keep the sidewalls in good shape.