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.