I have a spare pannier rack. My girlfriend commutes to work on an old hybrid bike with rear suspension. Right now she wears a backpack for her 1-mile commute, but we're moving and her commute will become closer to five miles, so we'd like to mount my old pannier on her bike to make her life easier. Can we make the two play together nicely? The bike is a Kent Sierra Madre, like this one (no endorsement implied -- this was just the first google hit). As seen in the image, the bike has a weird spring in the rear fork. The pannier rack is a fairly standard rear rack, like this (again, no endorsement, just for illustration). There are threaded mounting holes above the rear dropouts, but no place on the rear fork below the spring to attach the top of the rack. I have access to a machine shop and could build a clamp to attach the front mounting bits on rack to the fork below the spring. Would this be a terrible idea? If so, what are my other options? She regularly removes the seat/seat post to prevent theft, and wants to carry heavy school supplies + books in a pannier (she's a teacher), so I'm thinking that a seatpost-mounted rack is not an option. She's open to the idea of a new frame if this just won't work, but she likes that the current frame is so crappy that nobody will go to great lengths to steal it. Thoughts?

i got it to work once with that frame. I used these and these and clamped it on the frame right below the shock. It was not the best looking ever but worked in all regards.

You could possibly disable the rear suspension (remove the spring and put something else in its place like a short length of pipe) then mount the rack in a more normal way. Probably make the bike more efficient to pedal as well.

Try old man mountain racks.