While I do get questions about just how big a tire can be stuffed into the monster cross frame, I don’t get the same question about the road frames. Last week, however, I asked that question. I designed the road frame to fit a Jack Brown 33mm tire. At the time, 10 years ago or so, the 33mm Jack Brown was the largest, decent riding tire, that wasn’t a touring tire available. Today, there are plenty of 32mm (close enough) nice, supple tires. And with rims becoming wider, actual sizes of tires can be bigger than what’s printed on the sidewall. Combine a certain 28 tire with a wide rim and it may become an actual 30mm or more.
But, that 28 on a wide rim is still a 28 tire and because it’s bead is set into a wider rim, that pulls the outer tread down making the actual diameter slightly smaller. Not a lot, but smaller.
I’ve been running and trying to wear out an old set of Challenge Eroicas (they have since changed the name to Strada Bianca) that are labeled as a 30, but measure 32mm. They fit in my frame with plenty of clearance. And they feel good. And then I started thinking. “Will a 35 fit?” And I can say, “yes, provisionally.”
First, it depends on the 35 tire. A thick treaded touring tire might not fit. But a Compass Bon Jon Pass 700c x 35 fits. Provisionally.
There’s no issue with the fit at the chainstay or between the fork blades. The issue is with the brake caliper. Not all long-reach brake calipers are created equally. Some testing was in order. Here’s what I did to test the fit:
- Fit a Compass Bon Jon Pass 700c x 35 tires to wheels built with Velocity A23 rims
- Fit wheels into frame front and rear
- Check clearance with popular (read only) long-reach, 47-57, brakes available
The photos do a better job of showing how the tires fit. All the photos are of the front, but the rear is virtually the same.
Note that all parts listed above are for sale at Black Mountain Cycles. I don’t do a great job of pushing that issue, but, yes, I sell stuff and usually sell stuff I write about.
(What’s playing: Patty Smith Boy In The Bubble)