kingkenobi

So the slot where you insert the hex key to loosen the screw is stripped. It's the only damaged part in the shifter, and I'm at a loss as to how to remove it without damaging the other parts.

fietsbob

Remove the whole thing from the handlebar ?

FBinNY 

The first thing I'd try is to loosen it by turning the outer assembly. Place a philips screwdriver across the body - through the lever bolt holes - and turn counter-clockwise to back the body off the bolt. This works 95% of the time, though if the screw is bound to the body with corrosion the unit may turn without loosening the bolt. In that case, soak everything in Kroil or something similar (IME, Kroil is the best in the category) and try again the next day.

Worse comes to worst, you can usually turn a jammed unit and work it out with brute force even if the screw refuses to back out.

dsbrantjr

If FB's suggestion fails it is possible that a slightly larger fractional size hex key or a Torx key could be forced into the stripped-out hex socket, or a sacrificial one could be epoxied in to enable its removal.

You are turning it in the correct direction, right?

kingkenobi

that's one possibility that's flitted through my mind, and yes, lefty loosey as indicated by the threads

kingkenobi

as you can see the shifter is already off of the handlebar. The screw that locks it into place and secures it is stuck in the assembly, and had to be drilled through to get it out. AFAIK, that's the only damaged piece in it, and if it were to be replaced the shifters would work just fine

fietsbob

Might still have to score a whole one just for parts .. given how long ago they ceased making them..

likebike23

I'm pretty sure that it's reverse threaded.

fietsbob

the threads are cut RH.. but the head is facing away from the back.

when reaching past the hub across the wheel , tightening spokes, you think backwards, on the far side if the rim.

FBinNY 

No-o-o-o-o-o-o-o-o!!!!

You need to turn the screw to the right. Yes it does have a right hand thread, but you want to turn the screw so it goes deeper into the handle bar.

It's basically a flathead countersink screw with a countersink which when tightened toward the body expands the wedges tightening the bar end. To loosen picture yourself inside the bar applying the "lefty loosey" mantra. Since you're standing on the opposite end, it's righty loosey in this case.

kingkenobi

The threads slope down to the left.

Andrew R Stewart 

Yes the inside the bar bolt is right hand threaded. BUT from the back side that is how you access the bolt it becomes a left hand thread. Think about loosening the screw from behind the wall, if you were able to grab the screw end. If the bolt is frozen in the lever body then drilling it out might be the last choice to get the handle bar free of the shift lever. Next time apply lots of grease. Andy.

kingkenobi

#19 is the part i'm talking about. Unless british engineering at the time was wacky, it appears that the bottom of the screw is where the hex key inserts, and drags the top (thick head bit) down, which causes the expansion clamps (#17) to expand, locking it in place.

Andrew R Stewart 

This thread has a few discriptions of threading direction that muddy understanding. Up/down, turn left/right. I always took issue with these types of discriptions. They depend on a frame of reference that is not stated but assumed. The use of RH or LH thread discriptions are not subject to whether the wrench is above or below the fastener.

I remember being so proud of a bike ride i had mapped out years ago. Brought it into work to show my boss. The first thing he said was that their was a basic item missing. Which way was North... Andy.

kingkenobi

it's rather simple
left = counter-clockwise
right = clockwise

top = head of screw
bottom = bottom of screw, or the part that goes into the hole

Andrew R Stewart 

No for some people it's not so simple. If the wrench is above the fastener then you are right . But if the wrench is below the bolt then you are wrong. That's a 50-50 chance of being wrong. Not too good a record. There are times where a wrench won't fit in the way that you assume (ASSUME) that will be done. People turn the bike upside down all the time to work on it. People work from "behind' the fitting to get better pruchase on the nut/bolt.

Maybe I'm a ludite but this is one of the reasons that being digital is not going to get you ahead. Anolog thinking has it's place. Andy.

FBinNY 

My favorite way of dealing with threads is to apply the right hand rule.

Make your right hand into a loose fist with the thump pointing out, as if hitch hiking.Place it along or near to the part you want to move. If you turn the hand in the direction the fingers point, it'll move the way the thump points. The same for the screw you're using it to represent.

If the screw has a left hand thread, use the same method with your left hand.

The beauty of this method, is that you don't have to track the point of view or anything, it never fails. Even after 45+ years of turning wrenches, I still find myself doing a reality check and using my hand to confirm which way to turn the part.

kingkenobi

that 50-50 chance goes to 100% of being right when you take into account that the screw is upside down.

kingkenobi

ok now i get what you mean

likebike23

You learn something new every day. I never really examined it, just assumed left hand threads because of the clockwise removal. Thanks Fietsbob and FBNY for the explanation and kingkenobi for the diagram.

kingkenobi

that diagram is bound to be invaluable to me