Velocity A23 Rims in 650B and 26″
If you’re running 700C tires on carbon rims, the wheel situation is better than ever. As companies have rolled out new rims, they’ve redesigned them to (mostly) meet the ETRTO / ISO standards for rim/tire fit. That’s good news, whether you run your tires tubeless or with tubes.
Things don’t look as great for 650B bikes, where rims have been an issue since that wheel size first became popular again. And decent 26″ have become even harder to find. Especially if you’re running rim brakes.
A few years ago, we drafted a rim and shared our design with Kirk Pacenti, who was looking to replace the crack-prone PL23. With a few tweaks from Kirk, the results was the Pacenti Brevet rim. However, Kirk sold his company, and the new owners seem to have ‘paused’ the company for the past year. So we need a new source of rims.
Rim designs tend to be hit-or-miss: Different rim models from the same maker can either be great, or have insufficient sidewall heights, or even suffer from cracks after just a few years of riding. We’ve looked far and wide, and the Velocity A23 is our favorite rim.
I’ve been running them on my 26″ Rene Herse bikes (above), and they’ve been through multiple Oregon Outbacks, Unbound XLs, Arkansas High Country Races and more—without any trouble at all. In fact, I haven’t even trued the wheels yet.
The triangular shape is a logical way to design a rim, because it offers the best load paths for the spoke tension. The A23 is remarkably lightweight—425 g for the 650B version—yet there are none of the problems with cracking that trouble so many modern aluminum rims. The diameter is spot-on: The tire beads seat securely, but the fit is not too tight. The inside sidewall height (G height) is 5.5 mm: about perfect for running tires with tubes, and at the lower end of the tolerances for tubeless. Velocity says the A23 is tubeless-compatible. In our experience, the tire tends to drop into the well when the air is released. That makes removing the tire much easier, but it’s not ideal for tubeless. Let’s say: You probably can run the A23 tubeless, but it’s really optimized for running with tubes.
The 23 mm width is about perfect for tires up to 45 mm wide. You can run tires as wide as 54 mm, but if you run canti brakes, the brake pads can hit your tire when the brake opens. The tire is so much wider than the rim, and the brake pads swing upward as the brake opens. If you set your brake pads low enough that they don’t touch ultra-wide tires, they can ‘dive’ under the rim when braking hard, and you lose all brake power. (On my bikes with 54 mm, the canti posts are carefully placed to minimize this problem, and yet I have to check my brake pads before every ride/race.) Contrary to common belief, there are no handling concerns with ultra-wide tires.
For most 650B and 26″ bikes, the A23 is really just about the perfect rim. Making it wider would make it a lot heavier—without any benefits unless you run ultra-wide tires. Maybe some day, there’ll be an A30 for those ultra-wide tires…
Velocity makes the less-common sizes and polished versions of the A23 to order. We are offering 650B and 26″ rims, both polished and anodized black. We spec’d machined sidewalls, because we want our wheels to offer optimum braking from the get-go, rather than wait until the rims are ‘machined’ by the brake pads during the first few hundred (or thousand) miles. We’re not offering an offset version for the rear—we prefer spokes to connect in the centerline of the rim for maximum durability. Velocity’s logos are quite large, but the stickers are easy to peel off, if you prefer logo-less rims.
We have the 650B and 26″ rims in stock in limited quantities, with 28 and 32 holes. We also offer the excellent Sapim Laser spokes for your wheel builds.
More information:
- Rims and spokes in the Rene Herse program.
- Why wide tires don’t need wide rims.
