The best sound is no sound. Then when you come up on somebody on the road, they won't know you're there. That way you can sleighride and when they jolt to awareness that you're sittin' on, wheth er its a block or a mile+ tell 'em you've been on for miles
Excuse me, but I for one would be really pissed if someone rode up on my wheel without announcing him/her self-----"On your wheel" is the proper salutation. If I don't kno you're back there and I suddenly sit up or tap the brakes for whatever reason, then you're crashing into my rear wheel, with most likely dire results to you. Serve you right, in my opinion.
Nor Meyer in Mt. Vernon, IA