A member or two has mounted bicycle pedals on their Rebel, but I can't find the thread showing how they did it. It would be costly, but you may have to have adaptors made in a machine shop if you can't find any commercially.
kuryakyn might have some adapters, but youd want to get them with their pegs. theyre a little pricy but very high quality and great customer service! I actually measured the mounts for my brackets on my 450 and they promptly responded with a set of adapters that may work with mine! send them a dm with the dimensions if they dont have one listed that fits!