Rear derailleur shifts to lowest gear without any adjustment
I'm new and I don't know what is going on with my bike. The bike has down tube shifters which I can adjust however the rear derailleur keeps shifting the chain onto the smallest wheel. How can I fix this?
Insane Bicycle Mechanic
OK... first some terminology: the smallest cog on the rear wheel is the highest (hardest to pedal) gear. Most normal derailleurs will shift into this gear without something to hold them back. That something is usually the shift cable, held in place by friction at the shift lever. You should look for a wing nut or screw on the shift lever and tighten it down enough to keep the shift lever from moving once you've selected a gear.
Originally Posted by zatara