Hey folks, I need your help. I’m currently restoring and old mtb (barn find). Yesterday I’ve tried to dismantle the cogset (Shimano MF-HG20). The manual of my bicycle repair kit said one of the tools (the one with the spike – see pictures) is for dismantling cogsets so I tried to use it, but the rear axle was in the way of the spike. (I later found out that shimano offers a suitable tool for MF-HG20 cogsets). The problem is, that I’ve already dismantled the rear axle, so that the axle doesn’t interfere with the spike of the tool and a total of 18 bearing balls fell out, when I removed the axle…. I know that 9 of them belong to the left side of the rim and are secured by one part of the axle (I call it part A – see pictures). But I genuinely have no clue where the other 9 bearing balls belong to. I guess they belong to the right side of the rim where the cogset is mounted but other than that- no idea.
Has someone a exploded drawing of the rear wheel or any tips where I should put the remaining 9 balls?
by No_Astronaut0
1 Comment
The MF-HG20 isn’t a cassette, but a freewheel. You need a freewheel tool. The freewheel tool will take off the freewheel.
Once that is off, you’ll see where the cone fits over the ball bearings that were hidden by the freewheel.
In most cases, mechanics will remove the axle from the non drive side after the freewheel is off. Park tool has a good tutorial:
https://www.parktool.com/en-us/blog/repair-help/freewheel-removal-and-installation