in 1979 at the Red Zinger I watched Tom Ritchey wash the Dale and Wayne Stetina's bikes after the Red Zinger bike race in Estes Park. off topic( he had the first mountain bike I had seen there. neat blue anodized 26" rims and huge tires) Run entirely in the rain. the bikes were pretty dirty after a couple of hours in that kind of downpour. He used a bucket of soapy water and a brush.... he said it is better than ridding in the rain and got the crap off quick, then he proceeded to wipe the bikes down after rinsing them in clear water.... I have been doing the same thing for over 30 years and see no problems. I use sprayed on mineral Spirits on the chain and derailleurs and chainrings. then rinse off with 409 and clear water. then re- lube.
Chuck Johnston
Fort Collins Co