Pacenti’s SL23 rim has been a favorite alloy road rim of many wheel builders (myself included) for a while now.  It struck a nice balance of weight, width, depth, and stiffness, and had a great brake track and build quality, and is tubeless ready.  Like all things, there was still some room for improvement however.  Many users had trouble getting tires on, because it’s a tubeless-ready rim which requires a tight fit with the tire.  There were also a few rims that cracked at the spoke holes.

2015 SL23

To address those issues, and make a great rim even better, say hello to the 2nd generation SL23.  With this new version Pacenti aims to keep the good qualities of the 1st gen rim, and improve on it’s shortcomings.  To make tire installation easier the center channel is deeper, and the rim sidewalls are about 1mm shorter.  The spoke bed has been thickened by about 15% to reduce the chances of cracks forming.

Graphics are unchanged.
Graphics are unchanged.

Those aren’t the only changes either.  The rim is a touch wider now as well, with the external width growing from 24mm to 24.6mm.  The bead hooks were made smaller, which both reduces weight and increases the internal width.  The inner width has grown from 18mm up to 20.3mm.  Weights have dropped a bit, the two I have on hand both measuring a touch below the claimed 430g.  Last but not least, the new rims have a bead blasted finish, which isn’t as shiny as the old finish.

The old rim is on the left, the new version is on the right. You can see the difference in the finish and the brake track height.
The old rim is on the left, the new version is on the right. You can see the difference in the finish and the brake track height.

There is one downside to these changes however, the shorter sidewalls have reduced the brake track height from 10mm to 8mm, so you’ll want to use some narrow pads, such as Kool-Stop’s ‘Dura 2’ pads.  All in all however, I think the changes result in rim that is better than the old.  It’s wider, easier to get tires on and off, and even shed some weight along the way.

1st gen. rim on the left, the new on the right. The new rim's bead hooks are smaller, and the center channel is deeper.
1st gen. rim on the left, the new on the right. The new rim’s bead hooks are smaller, and the center channel is deeper.