One of the best cleaners I've found as far as both results and price, is a product called "Totally Awesome" liquid. It's a yellowish color and can be mixed at various strengths according to the job at hand. Cost is about $1 or $2 depending on where you buy it. You can get it in a spray bottle and a larger refill bottle. It can be used for hundreds of cleaning projects, just choose the strength you need. I buy it at Dollar General or Dollar Tree. It doesn't seem to damage paint at all. I've used Simple Green before due to its degreasing capabilities, but Totally Awesome does the same degreasing job at half the price. I use about a 20 or 25 to 1 mixture of Awesome cleaner/degreaser to water. Totally Awesome and a soft cloth gets the bike clean in less than an hour, including a cleaning/degreasing of the chain. It seems unlikely that a product priced so economically could so effective cleaning so many things.