Thursday, September 1, 2016

Will Specialized Fast Trak 29 x 2.0 tires fit a Surly Cross Check?

The tires look meaty and tough on the bike, but neither wheel will roll without buzzing contact with the frame and fork.
Uhh... nope. Not quite. After his recent visit, Nick left me a pair of Specialized Fast Trak Sport 29 x 2.0 tires. Though a little worn, they're nice tires with plenty of rubber left and a fast looking tread pattern. It was the perfect opportunity to see if a skinny (by current standards) 29er tire would have a chance of fitting my 58 cm 2001 Surly Cross Check. I did a little preliminary research and found reports of some success in fitting 50 mm Schwalbe Big Apples, and a couple of random 1.95 inch 29er tires on Cross Checks, but couldn't find anyone on the whole internet who had tried Fast Trak 2.0s. So here I am to provide that public service.

The results: close, but no cigar. The tires mounted on 20 mm wide Mavic MA3 rims measured out to be almost exactly 50 mm to the outer profile of the knobs. Maybe if I shaved off all the side knobs and had perfectly true rims, there might be a millimeter or so of clearance on each side. I'm not willing to do that. Maybe. However, I've been wanting some fatter tires to replace the pair of nearly worn out Bontrager 38 mm tires (measures out to 34 mm mounted on my MA3s) that I've had on the Cross Check for a long time. Even though the experiment failed, it points to the likelihood that something in the 1.8" to 1.9" (approximately 46-48 mm) wide would be about the right amount of fatness. I could probably even fit fenders with the right tire. I know the 700 x 41 mm Surly Knard is a sure fit, and equates to about 1.6" wide. However, I'm convinced there's a skinny 29er tire out there that will have sufficient clearance, yet push the envelope just a bit more. We don't have a lot of mud here in Colorado, and I wouldn't be riding muddy trails on this bike anyway, so minimal clearance is fine in my book.
Fast Trak 29 x 2.0 on the front.

Mavic MA3, 20 mm wide, on both front and rear.

Plenty of top clearance, not enough side clearance in the fork.

Right fork leg.

Left fork leg. Tantalizingly close to clearing, if not for knobs.

Yep, still 2.0. No better luck in the rear.

Axle slammed rearward in the dropouts.

Close, but not quite clearing the chainstays. 

Seatstays close to clearing, but not. Less room below the brake bridge than below the fork crown, but still adequate.