Join Date: Aug 2013
Location: Wimberley, TX
Thanked 28 Times in 24 Posts
Tire question for racers: Bridgestone GP Moto3 Slicks?
I have a question for you other CBR250R racers: My Bridgestone sponsor convinced me to try out a set of their GPR125 slicks on my CBR250R at Hallett this last weekend. I only got one practice session on them (and then I crashed out on my CBR600RR - cracked rib, wadded bike, concussion; lots of fun).
The tires are 120/60/17 rear / 90/58/17 front mounted on the stock OEM 140/70/17 rear / 110/70/17 front. I snuck up on them slowly in the practice session, and I never felt like I got them up to speed. But when I checked my times, at the end they were the same as my times on full size DOT tires. So I think there's some speed advantage to be gained.
My rear felt solid and planted, but the front felt "bouncy". I'm not sure if that is the result of a more flexible carcass or changes that I need to make to my suspension. (My suspension guy wouldn't help me, stating that running 125 tires on a 250 was dumb and he wouldn't be involved.)
So my questions - Is it dumb of me to even try these out for Bridgestone? If not, can I work them into the same kind of corner speeds as the full size DOTs? If any suspension changes are need to the front, what do you suggest? Any general advice?
Thanks in advance to any racers with relevant experience! (Non-racers, please don't just speculate on this topic - I know the dangers - I race.)
2012 CBR600RR - Track Bike
2012 CBR250R - Track Bike
2012 Ninja 250 - For Sale