Sunday, August 28, 2016

650B, Third Time the Charm?

For a wheel size that has been around for decades, rim makers have struggled to make a decent 650B rim. 650B has many attractions: it may allow you to squeeze fatter tires into a racing or sport frame, and there are some fine tires in that size. But it seems there are issues making a rim that fits easily with 650B tires.

My first attempt at 650B was with my Rawland rSogn. It was a great frame, both lively riding and practical, but both the rims and the tires were mediocre to bad. The Panaracer Col de Vie tires were somewhat sluggish, but the Velocity Synergy rims were downright bad: with a bead well that was too deep, it was almost impossible to get the tire evenly seated and rolling true (by the way, if you have an XL rSogn you want to sell, let me know).

650B try 2 was on my old Trek 620. This time, I had lovely, supple Compass Loup Loup Pass tires, but the rims were even worse. The Pacenti PL23 rims were nearly impossible to get a tire mounted onto. I pinched the front tube five times trying to get the damn tire bead over the rim. This was frustrating enough in my garage, but not something I'll live with on the road.

Is the third time the charm?

These Soma Weymouth rims are prettily polished like the Pacenti rims, but I mounted up tires on them on the first try. No wobbles, no pinched tubes, no flinging tire levers across the garage as I howl in frustration. This is something I take for granted on 700c rims, but a new experience with 650B.

The rims went into wheels which went on this new frame:

It's a 1987 Trek 330 frame that I bought off the iBob list. The previous owner had cantilever posts brazed on that were positioned for a 650B rim height: 

This pulls together several things I want in a frame: fattish tires, flexible tubing, strong brakes, and it was cheap! My image for this build was a geared road bike for solo rides--replacing my Raleigh--as well as something for puttering around the neighborhood with. To that end, I installed my first pair of interrupter brake levers (ignore the orange bar tape, that's just temporary until I finalize my brake position):

My thought was this would let me rest my hands up high on the flat part of the bar, while still giving quick brake access when one of the kids stops suddenly. These are the somewhat rare Tektro RL740 levers, designed to have enough cable pull for V brakes. The only other option were some levers from Paul's, which would have cost nearly as much as I paid for the frame. Never having used these levers, I'm pretty impressed by them: the power is as strong as normal levers, not at all like the "suicide" levers on old 70s ten speeds. Because of the shape of my Salsa Bell Lap handlebar, the only position I could mount them was almost straight down. Not the most ergonomic position, but it works well enough. After riding them for a bit, I did realize I put them too far outboard. This limits where I can put my hands on the top of the bar.

Aside from the wheels and tires, I didn't want to spend anything extra on this build. I dug through my parts bin and pulled out what would work, and stole some castoff 26" fenders from Jodi's old mountain bike (now Henry's), along with a $10 front rack and that orange bar tape:

My drivetrain is friction shifted 2x9, with one of my two Suntour XC Pro cranks giving me a 44t ring for general riding, and a 34t ring as a bailout gear, along with a nice, narrow Q factor:

The rear shifter is on the bar end, while the seldom-used, stolen-from-my-Raleigh front shifter is on the down tube:

Plenty of beausage, and/or random paint scratches and chips, but I like this nice seat lug:

It all comes together wonderfully. The ride is fast, smooth, and comfortable. The 38mm Pari Moto tires seem on par with the Compass tires, at about half the price. I'm finding this size is really a sweet spot for me for general road riding. It's big enough to smooth out rough roads and unseen bumps, but not too big that it feels like a mountain bike.

Alas, there was a small fly in the ointment. Saturday, I rode for nearly three hours, stopping for a mid morning break near Ostrander:

I passed this yard full of yard art, and took these photos for my mom who likes this sort of stuff:

Back to the bike stuff. On this ride, I was never as comfortable as I was on my Raleigh. Even with an upjutting stem, I was still reaching too far to the bars. The tape measure reveals the truth: the Raleigh's head tube is 15mm taller, while the ETT is a whopping 25mm shorter. This brings my bars up and back on the Raleigh, making it the only bike where I've truly been comfortable on drop bars.

That got me to thinking. The longer, lower bar position would make the Trek a better setup for some type of flat or upright bar, rather than a drop bar. With the strong brakes, fat tires, tough wheels, and fast frame, it could make for a nice city bike. And it turns out my Raleigh Technium can clear the Pari Moto 650B tires, potentially making for a fast and comfortable drop bar ride.

Clearly I need another set of 650b wheels. Good thing I know some decent rims to work with now.


  1. I've had experience with some of the same 650B rims you have (not the Soma), the PL23's seem a bit more manageable with a slick tubeless tape but they are still really tight. I'm running A23's on my Saluki w/ Parimoto 38's right now and they are easy to mount in comparison though I'm not sure I am as attuned to the rim-tire fitment issues people have with the supple tires. I've also got 2 synergy wheelsets between a couple bikes and managed to get satisfactory (for me) tire seating.

    I'm currently going back and forth about cockpit/reach/comfort on my Saluki having swapped out Albatross bars for Noodle drops recently. Definitely a tricky subject.

    1. I looked at a wheelset with A23s, but read kind of mixed feedback on them. Good to know there may be a second acceptable 650b rim out there.

      I just put 650b wheelset on my Raleigh Technium. The combination of fat, supple tires and noodly frame is really quite wonderful so far. More to come!


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