A loose drive-side crank that
won't tighten on a Kenevo SL is annoyingly common, and the good news is it's almost always fixable without new parts. Here's what's going on.
The likely cause
On the Specialized SL motor (the 1.1 unit in your 2023), the drive-side crank sits on an ISIS spindle. When the pinch/centre bolt is done up and the arm
still feels loose, the usual culprit is one of these:
•
The arm hasn't seated fully onto the splines. We've seen Kenevo SL framesets turn up with the drive-side crank only
half onto the spindle and the central bolt not even finger-tight — so the arm wobbles no matter how you torque it. The splines have to fully engage before the bolt has anything to clamp against.
•
Worn or galled splines from running it loose. If it's been creaking/loose for a while and you've kept riding, the ISIS splines can round off slightly, and then the bolt just spins up without ever locking the arm solid.
•
Spindle play in the motor itself. One Kenevo SL frameset was found with ~3mm of play at the cranks/motor spindle — that's a motor-side issue, not a crank one, and no amount of bolt torque fixes it.
How to fix it
1. Pull the drive-side arm right off and inspect the splines on
both the arm and the spindle. Look for rounding, galling or alloy smear.
2. Clean everything, then refit making sure the arm is pushed
fully home onto the splines before threading the bolt.
3. Torque the centre bolt properly — Kenevo crank arm spec is around
20Nm. Don't guess it by feel; a loose-then-galled spline is exactly how these start.
4. If the splines look chewed, a smear of retaining/threadlock compound on the splines is the known workaround —
@XFi → view post used exactly this on Cube Hybrid cranks for the same slipping issue, and it carries over.
5. If there's
play in the spindle itself (arm fully seated, bolt torqued, still wobbles) — that's a warranty/dealer job on the motor, not something to bodge.
Worth noting Praxis alloy cranks on the KSL have a poor durability reputation —
@Blownoutrides → view post went through roughly six bent sets — so if yours look at all tweaked, factor that in.
If you can get a photo of the splines on both the arm and spindle, I'll tell you whether it's a clean refit or a replacement job.
