These don't even work with my son's 20" brand new Specialized Riprock bike.

Rear axle interferes with knob making installation impossible. Falsely advertised as compatible with Riprock 20” Coaster. It is not.

I bought these to fit on a RipRock Coaster 20. The hole in the training wheel arm for the rear axle is too small and the rotational stop pin on the training wheel arm doesn't line up with any of the holes in the frame. I know the description here of the part says it's compatible with "2013 and newer RipRock Coaster 20", but it is no way compatible. The chat support suggested taking it to a shop to have the "axle trimmed", whatever that means. Even if I made the axle hole in the training wheel arm larger to fit over the axle, the rotational stop pin on the training wheel arm does not line up with any feature on the frame of the bike. I know it's just training wheels, but getting the compatibility correct shouldn't be that hard.

great design in that they can be easily removed separately from the wheel but we did need to trim the rear axle studs to install for the RipRock model

I pretty much have the same comment as the previous reviewer: the installation was not "tool-less" as advertised because the hand-screw knob is too large to fit with the other components on the bike. Once on, however, the training wheels are great!