Any degreaser will work on chains and gears, but some will damage seals, brake pads, paint and finishes so be careful not to get it on anything else. I used automotive degreaser's without problems; I used Simple Green but found it to be not as strong as I like it; now I use Finish Line degreaser and it actually works the best of the biodegradeable stuff I've used in the past...though still not quite as good as automotive degreasers.