i am trying to replace my Hollow axle with a Chrome-Molly axle, I ordered the new Chrome-molly axle but am not sure how to arrange the nuts properly. (which nut goes to where the cassette it and which goes on the other side)
To change an axle, you have to remove the old one. When you remove the old axle, take note of how the nuts were installed on the old axle. If you are installing a solid axle thinking that it will be stronger that the quick release axle you currently have you may be disappointed. Quick release axles are actually stronger than solid axles. I used to have a mountain bike that had a solid rear axle that used to break about once a year, even when I used the best quality axle that I could buy. I cured my problem by installing a hollow quick release axle, once I did that I rode for many years with no further problems.
