fredsc

Hi,

I have a Marukin bike, with a Suntour derailleur, from the 1990's, and lately when I shift into the easiest rear gears, it won't stay there; it shifts back to the harder-to-pedal gears. The only way it will stay in the easy-to-pedal gears is if I forcibly hold the gear changing lever in the correct position; as soon as I remove my hand after the shifter lever, on its own the bike goes back into the harder-to-pedal gears. I checked the limit screws, barrel adjuster, cable tension, and derailleur hanger but all seem okay. Is the derailleur broken or needs a new spring?

Fred

andrewclaus

It sounds like you have a friction shifter, one that doesn't "click" into discrete positions. If so, there's a screw or wing nut on the shaft of the shifter you can tighten to add more friction.

Iride01 

My '78 Raleigh with Campy friction shifter use to do that all the time but on the front shifter. It just needed to be tightened up. But sometime in a few weeks it'd get loose again. Never did bother to look if anything had gotten left out when reassembled or that it may have been put together wrong. The various manufacturers of friction shifter either just had a knurled edge of the body you just tightened or had a bail you pull out to tighten them.

I missed out on the early days of indexed, so if these are indexed downtube shifters, then I'm not sure, but I'd think pretty much the same.

cxwrench

The thread title says 'smaller rear cogs', the post says 'easiest rear gears'...which is it? As posted previously it sounds like a friction down tube shifter that needs to be tightened a bit.

Iride01 

Title works for OP and replies though if smaller is meaning the lower ratio cogs.

fredsc

Thanks, your solution solved the problem!