Adjusting the trigger pull on Shimano STX shifters?

August 23, 2014 1:00 AM

I just put some new ergonomic grips on my mountain bike, and they're slightly thicker rubber than the older ones. The tiny bit of extra circumference now obstructs the pull of my trigger shifter. When I try to go into a higher gear there's not enough clearance for the trigger to engage the ratchet in the shifter and move the dérailleur. I can force it if I squeeze hard enough and push the lever back out, and the bike shifts gears fine, so the issue is not cable tension. My question: Is there a way to adjust the trigger pull to be slightly further away from the handlebars?

I'm rocking some vintage Shimano STX shifters. They're in pretty good condition, and up until I put the new grips on worked a charm. I'd like to see if there's a way to adjust the levers so that the trigger pull (which I use my index finger to activate) is a millimeter or two further away from the handlebars to begin with.

There's a nut on the bottom of the unit that looks like I could loosen it and the trigger-pull and thumb-push levers could be rotated closer together or further apart. But I'm scared to mess around with it without knowing what will happen when I loosen the nut. I can't have the entire assembly falling to pieces on me right now.

I'm taking this bike out on an extended series of rides next week, so I'm kind of short on time. Otherwise I'd be taking this to good ol' LBS at my leisure.

posted by carsonb to Sports, Hobbies, & Recreation (6 answers total)

Instead of moving the shifter in relation to the grips, can you remove material from the grip where it interferes with the shifter?
posted by plinth at 3:28 AM on August 23, 2014

Best answer: Don't try to take that shifter apart unless you're cool with thing flinging tiny parts across the room. Ask me how I know.

I would move the shifter inboard to solve this problem. To my knowledge there's not a way to adjust lever reach on those shifters the way you can adjust brake levers.
posted by spikeleemajortomdickandharryconnickjrmints at 3:50 AM on August 23, 2014 [1 favorite]

Best answer: Perhaps you can put a shim under the shifter (above the bar) to move it up slightly? If the shifter would work on a slightly bigger bar, then that's likely to help. As long as you loosen the correct bolt (I.e. the one that tightens the shifter onto the bar), there's very little that could go wrong.
posted by JMOZ at 5:33 AM on August 23, 2014

Best answer: I was about to say what JMOZ said. Cut some strips out of a beer can for shims (my go-to for thin metal shims). Two or three ought to do it.
posted by notsnot at 5:48 AM on August 23, 2014

Response by poster: That worked! Thank you very much!

....now I just need to get this overnight flat figured out. =\
posted by carsonb at 7:24 AM on August 23, 2014

Response by poster: I did also move the shifter inboard about 2mm which, now that I've looked at it so closely, might have been sufficient. I thought it was hitting before right at the end of the lever where my finger rests, but it very well could have been further in so moving the shifter in solved that potential source of the problem.
posted by carsonb at 8:12 AM on August 23, 2014