They said they’d never do a road tubeless, but I guess they realized they needed to get with the times:
They’ve stopped making the 4000 so watch for clearance sales!
Sweet, another tubeless tire to try!
Like many, I imagine, I’ve been a GP4000 user for awhile and also been intrigued to go road tubeless. These are interesting to me, but I wonder the best way to determine the likelihood that a larger size will fit my frame. I’ve always been running 23mm.
I have a Felt B16 for Tri and wonder if a 25mm would fit. Obviously buying some and trying them out is the most certain, but are there any good sites to estimate the mounted width and height of the tire on a common rim (Velocity A23, for example).
I would upgrade my Road bike to 25 and keep the Tri on 23, but I still share an old PowerTap wheel between bikes and prefer not to swap tires so often.
I hope this isn’t too off-topic.
The 25mm GP4KSII measure out to about 28mm on both my Bontrager and ENVE wheels.
My chainstay opening is about 36mm:
The ETRTO standard EN14781 calls for 4mm of clearance between tire and chainstay. So in my case, with a 36mm chainstay clearance, a 28mm inflated tire has 4mm clearance on each side (4 + 28 + 4 = 36mm).
I have ridden the GP4000S in 25mm for a long time. Mine are currently mounted to a DT Swiss RR1.1 Rim and they spec out at EXACTLY 25mm.
The rim is old school, (Trainer Mule now) and the dimensions are 14mm inner width, 19mm outer width. On that old Cervelo the problem wasnt width, but height. The diameter on such a narrow rim was larger, and as such the tire would rub against the (absurdly close) brake bridge on the back. I took care of it with a file, and all is good, though I’m not recommending that method.
I will absolutely go with tubeless 5000’s on my new road bike.