A year ago, I purchased some Velocity 650B rims and 40mm-wide Panaracer Fatty Rumpkin tires. The intention was to convert my fixed-gear Pacer (built with Karate Monkey dropouts) to a 650B bike. Well, that never happened. And I'm glad it didn't, because my geared blue Pacer is better suited to use the 650B format.
The Pacer fork doesn't accept 40mm-wide tires, so I swapped it with a Steamroller fork. The axle-to-crown height of the Steamer fork is 3mm taller, and the offset decreases by 7mm. The trail measurement changes a bit, but the resulting geometry (61mm of trail) feels just fine for a bike of this nature. There's plenty of room for the "big" tire in the Pacer frame.
Smaller rims (584mm ISO standard vs. 622mm) require longer-reach brakes. The DiaCompe Mod 750s work great for this project. The pads (Jagwire Cyclocross cartridge-style pads) sit toward the middle of the brake arm slots, so I have a lot of room for adjustment.
The initial rides with the new wheels commuting to and from the office proved successful. My conversion had not been done in vane. The increased comfort, provided by larger air volume and lower pressure, was very noticeable compared to the 700 x 28mm Rivendell Ruffy Tuffys I'd been rolling to that point.
On the 16th, I loaded up the Carradice bags (same configuration as the last off-road outing) with camping gear and hit the dirt river trail, keeping 60psi in the tires. The Pacer hauled ass on the hard single-track and performed admirably when the trail got soft and loose. The inverted Fatty tread hooks up well on dirt and gravel, but doesn't add noticeable drag or noise on hard surfaces. This set-up is going to live on the Pacer for a while. I like it.
The potential downside of 650B-equipped bikes is the availability of tires and rims, compared to 700c and 26 (559mm ISO standard) formats. But several companies are promoting and supporting this wheel size Rivendell, Panaracer, Schwalbe, Pacenti, Velocity, Rawland, Kogswell so this will likely be less of an issue in the future.
How was camping? Awesome. Thanks for asking. The river trail is a bit overgrown, and my legs burned and itched, for a while, from contact with the stinging nettle. That generally subsides with a little time and a cold beer. If that doesn't work, I give it a little more time and crack another beer. Cool evening temps meant perfect sleeping weather. And few mosquitoes were out harassing me. A huge dragonfly did stop by to hang out while I was eating lunch, but she wasn't causing any trouble. We chatted about the weather, shared recipes, and joked about Sarah Palin. It was nice.
The breadpan stove fits in either Carradice bag, so it was the fire containment vessel of choice for this outing. It doesn't have a baffle, and it isn't airtight. But it draws (air) well and burns hot. Good enough for heating a lean-to and boiling water. I used the Hex Fly over my Hennessy hammock. I'd forgotten how big it is. It adds some weight, compared to the stock asymmetrical fly, but I like the increased protection when it's windy or raining.
Overall, the new bike configuration did what it was supposed to do, and the camping gear du jour kept me comfortable and happy. This one goes down in the books as another successful session in the sticks.