Hi. I'm 16 years old, and looking for an affordable rear-wheel electric conversion kit for my Schwinn Mesa GS mountain bike. I need it to have good hill-climbing ability; speed isn't that important. I need around a 15 mile range.

I don't want a front wheel kit because I'd like to keep my suspension fork (which is made of aluminum and would break with a front wheel kit). Most of the kits I've looked at are either front-wheel or expensive. Does anybody know of a less expensive one with the features I need?