I just got a new bike and it has v-brakes. Ive only used it for a few hours now and theres a thin layer of greasy black liquid on the rims. Iam guessing its coming from the brake pads. I was wondering how whould I go about cleaning them. Whould plane old water do the trick or should I use something else like rubbing alcohol. (I heard that you can use rubbing alcohol to clean your disc brakes, i though that it might be the same with rims). Thanks in advance!!!!!!!!