Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.merganser22
09-10-10, 01:48 PM
So I was pedaling along with minimal effort at probably about 80 or 85 rpm going about 20 mph and the path got bumpy and wham it my rear derauler shifted into a smaller cog. Happened twice. Is that normal for bumpy areas? I'm running all shimano 105 components except for the rear derauler which is a cheesy plastic suntour model. I'll allow that this may also be the culprit.