Bicycle Mechanics - Adjusting SunTour Accushift Plus shifters?

I have a 1990 road bike with SunTour Accushift Plus downtube shifters. The indexing (rear only) has been acting up a bit. I am wondering how adjustable they are. On the rear shifter, there is a sort of knob on the side, and next to it it says "7.......F", which I assume means you can adjust in between 7 speed indexing and friction mode.

Does anyone have these and know how to adjust them? I've tried playing with the knob but it's impossible to move it by hand, and I'm wary of forcing it with pliers or something.

I have a 1990 road bike with SunTour Accushift Plus downtube shifters. The indexing (rear only) has been acting up a bit. I am wondering how adjustable they are. On the rear shifter, there is a sort of knob on the side, and next to it it says "7.......F", which I assume means you can adjust in between 7 speed indexing and friction mode.

Does anyone have these and know how to adjust them? I've tried playing with the knob but it's impossible to move it by hand, and I'm wary of forcing it with pliers or something.Think you have to loosen the attaching bolt,adjust to friction and retighten bolt. You cold have a cable tension issue or problem with the piece of casing at the RD.

I have a 1990 road bike with SunTour Accushift Plus downtube shifters. The indexing (rear only) has been acting up a bit. I am wondering how adjustable they are. On the rear shifter, there is a sort of knob on the side, and next to it it says "7.......F", which I assume means you can adjust in between 7 speed indexing and friction mode.

Does anyone have these and know how to adjust them? I've tried playing with the knob but it's impossible to move it by hand, and I'm wary of forcing it with pliers or something.


You are correct about the friction vs indexing mode. If you want to continue to use the indexing mode, don't touch the knob leave it at "7". Index adjustments are all done on the rear derailleur adjustment knob, where the cable housing connects to the rear derailleur. Turning the knob clockwise will move the derailleur pulleys towards the smaller cogs, counter-clockwise will move it towards the larger cogs. You probably have to turn the know counter-clockwise to tighten up the cable which probably has stretched over time.

Good luck, hope this helps a little.

Thanks, kgatwork and sydney. I may have screwed up the indexing by fooling around with the knob on the shifters. I'll adjust the indexing before I resort to friction, but it's good to know that I have the option.

Thanks, kgatwork and sydney. I may have screwed up the indexing by fooling around with the knob on the shifters. I'll adjust the indexing before I resort to friction, but it's good to know that I have the option.

Switching the shifter between friction and indexing shouldn't effect the indexing once you place the knob back in indexed mode.

The suntour indexing stuff unfortunately is often not so hot, sometimes you have to settle with second best. I have found that the modern shimano freewheels/cassettes seems to work well with them despite having theoretical problems with cog spacing. Also don't know if this could apply to suntour, but from personal experience i found that having shimano downtube shifters in between the two modes would cause trouble. it would index fine between gears, but then would slowly upshift, esp when pushing hard.

Just to throw a couple of cents in, I just bought a used Raleigh Technium six cog with the downtube Accushift. It has a Shimano SIS freewheel. Tore it down replaced bearings etc and reinstalled. Didn't shift right, wouldn't go onto lowest gear. Adjusted the low screw and no help. Turns out the dude who had it before me, had the RD positioned wrong. I reset it, adjusted cable tension and then reset L and H screws. Shifts like a dream, smooth as silk and no noise. The Accushift must work with Shimano freewheel fine. Anyhoo, sorry to wax long.

Turns out the dude who had it before me, had the RD positioned wrong.

My problem turned out to be something similar: the RD mounting bolt was cross threaded :eek: :eek: I discovered this when upgrading the bike to Shimano 105/Ultegra... fortunately I was able to get the new Ultegra derailer into the original threads, but there's probably a helicoil in my future somewhere down the line...