Almost certainly bearings. I've been working on my own bikes for over 50 years & can nearly guarantee that. Inadequate lube can & will cause 1 or more ball bearings, and possibly the races, to become scored and cause the symptoms you described, especially under load. The surest solution would be to replace both sets of bearings & all 4 races in the rear axle. Even if they are sealed cartridge bearings, it shouldn't be terribly expensive. Can't help with a bike shop that makes house calls though.
|