Another front friction shifter problem A search gave me the 2011 thread about slipping shift levers, but I'm not convinced what my problem is quite the same. Manual on my '88 Bridgestone 400 says it has an AL11GS L434 lever SIS downtube mount type. I can read the SIS, and it's on the downtube, and the original owner paid no attention to this bike so I'm sure that's what it still has. I've had and ridden the bike for about a year. I had to tighten the tensioning bolt once a couple of weeks ago, which was no surprise. It loosened yesterday to where it settled on the smallest chainring, and I screwed the bolt tight again. My commute is not much more than 3 miles, and that bolt came loose both going in and coming home. I'm now riding with a stubby screwdriver in my pocket.

What could have changed? What part of this wears, and has to be replaced? I don't like the sound of Loctite as a solution. Holding the lever in position to be able to ride in the middle gears is not a good option. Help! Thanks.

mh
Friction shifters eventually need to be taken apart, cleaned, and re-lubricated to solve the problems you mention. Be very careful to keep the parts in order. You'll find advice on the above mentioned other thread not to lubricate them, which is wrong. All the surfaces should get a thin film of oil or grease, ideally something that doesn't harm plastic presuming your shifter has plastic washers, as most do. Using a mild or medium strength Loctite is optional but is a good further safeguard against slippage, and won't keep you from loosening them on purpose. Some people use beeswax as a substitute.

The plastic washers inside can degrade, which wouldn't be surprising on a 30 year old bike. If so you probably just need a new shifter unless you want to get crafty and find or make new ones.