Straightening a bent axle
28/07/10 11:14 Filed in: Cycling
I disassembled the front hub on the KHS and discovered that the cones were pitted in just one section on each, probably from being too tight on a slightly bent axle. I was hoping to replace both and figured it wouldn’t be too difficult since I at least knew the maker of the hub: KK. Unfortunately, this must be a small manufacturer and was not in the parts bible at the bike shop, so I decided it wasn’t worth replacing the axle either. I did, however, try a trick I’ve had some success with to mitigate the bend: placing the axle on the imposing stone (a heavy steel plate set in a table to plane hand-set type on, but any similar surface should work) and, with the bow of the bend facing upward, hitting it smartly with a hammer (try to avoid the threaded sections at the ends where the cones/nuts go). To get the last little bit of the bend rectified, place the end of the axle nearest the bend on a small washer. This way, when it’s struck, it has room to bend rather than just flexing. I cleaned, greased and reassembled the hub and it’s pretty smooth.
This is a different axle with a more pronounced bend which photographed better, though the camera seemed to want to focus just beyond the axle.
This is a different axle with a more pronounced bend which photographed better, though the camera seemed to want to focus just beyond the axle.