JeffOYB

I have an old Suntour Barcon that I'm trying to remove from my handlebar. One came out fine. Clockwise to loosen, etc. The other one is rounded-out -- the 6mm allen key can't get a purchase anymore. I've been soaking it in PB Blaster but with no purchase. The body will rotate with 10 lbs effort. Is there a way to get purchase on a rounded-out allen bolt? I don't have to use it often afterward. I just want to install it in another bar. Hopefully only one loosen and tighten. What about the Easy Out tapper? I just saw something like that at my hardware store -- it's made to smooth out a Phillips screw into a cone then grab that cone -- and turn counterclockwise. It seems to have 2 problems -- I don't have a Phillips "X" to grind/burnish out. Then it'll tighten not loosen. I guess I could saw apart the old cheapy 36cm original bars. Then clamp onto the base of the bolt to remove it, maybe. Ideas?

***

Also, do these things ever shift crisply? I've been having to shift a whole gear past then back again to get my gear. Like, from, say, the 15 to the 19 to get to the 17. Maybe if I install new housing and cables? Maybe the old rear derailler is flexied out and it's not the shifter. The bike and its parts are from 1976. Well, maybe some parts have been updated and I don't know how hard it was used. But I'd like to improve the shifting in some reliable way -- ideally with minimal fuss. I don't really want to change things that are working. I'm on a close-to-zero budget here. : )

HillRider

Try a Torx bit. Sometimes these will get a grip on a damaged allen recess.

AlphaDogg

That's what I'd try too. I think a T40 is about the same size as a 6mm hex wrench...

JTGraphics

Take a drill bit the size of the bolt threads or just slightly smaller drill head off the bolt when the drill gets to the smaller threaded section the Allen head will pop off and you can then slide everything off and remove the remaining threads and replace it bolt.

Airburst

They most certainly can...

HillRider

Won't work in this case. The wedge bolt on a barend shifter is reversed with the flaired head toward the front of the bike and the exposed allen recess is actually in the end of the bolt facing the rear where a nut would normally go. So there is no "head" to pop off at that end. The OP's only possibility, if the Torx won't grab, is to drill through the bolt deep enough to get an EZ-Out to work.

dsbrantjr

A threaded EZ-Out won't work because they have left-handed threads which will tighten the bolt in this instance. An un-threaded screw extractor like this one might work if you can find one small enough: https://www.sears.com/craftsman-5-pc-...5&blockType=G5

Perhaps there is a fractional-sized driver which can be hammered into the rounded-out drive recess.

It may also be possible to use strong epoxy to glue a sacrificial hex driver into the recess.

FBinNY 

Generally I find that I can easily loosen Barcons by urning the entire body in the right direction, The cone and expanders stay stationary until the entire assembly is loose enough to work off the bar.

Over the years I've found that this method is preferable than removing the units properly if the wedge is tight. As you've seen it's easy to round off the center of the wedge, plus the design is a bit problematic since as the hex key cams in the center it actually expands the threaded section in the body binding the threads.

If you can't turn the body by hand, you can get more leverage by using a band wrench (one of my favorite emergency tools), or lacking that, wrapping the body with an old belt and using a Channellock pliers.

JeffOYB

Interesting. I can turn the body. So I'll try to turn it some more to the right. It looks like that's what you're saying. Maybe. Actually, I can turn it already and it seems like it's just turning around and around. I'll try a torx as well. Man, I really want to make this bolt re-usable...

FBinNY 

If it's turning, keep turning is as you draw it out. It'll be easier to deal with once it's out of the bike.

HillRider

You need to turn it counter-clockwise to loosen. Remember you are trying to unthread the "nut" (shifter body) from the "bolt" (the expander wedge bolt).

FBinNY 

Yes, good catch. You turn the body counter clockwise to back it off the stationary wedge bolt.

Which brings up another point. Is it possible that you were turning the bolt the wrong way? You turn the wedge bolt to the right (clockwise) to move it deeper into the bar and off the wedge set.

For future reference here's a reminder of the right hand rule which will help avoid this confusion. Make your right hand into a fist with the thumb out like a hitch hiker. Now, if you turn in the direction your fingers point a screw laid across the palm will move in the direction your thumb is pointing.

Phil_gretz

Over last weekend. Mine were corroded into place and wouldn't rotate at all. You're ahead of the game.

Skipping ahead until after I had broken them "loose" to rotate within the bar...

I clamped the shifter base into my bench vise (using leather to protect the sides) where the profile appears to have a flat edges, allowing the flange with the cable stop to protrude outside of the vise jaws. I then rotated the handlebars in the direction of loosening (don't make me describe that) while pulling away from the vise with the bars. They inched themselves out. Worked for both sides, and I didn't damage the shifters. Make certain that you keep the levers installed when you do this, as I wouldn't clamp empty aluminum mounts into a vise - might crack them...

Good luck. PG

fietsbob

Crisply, ? you mean like a key on a keyboard? remember it is not the lever
that pushes the chain sideways.

Have 30 years on the ones I have, Multiple International tours, with 'home' aboard.

you might take a while to re learn how to shift a bike without the engineering
features that shimano flooded the market with.

I'd say Terrain reading and anticipating the shift before you need it. is #1.
older mechs shifted late , so mind had to work early,

now the stuff shifts early, so mind goes in freewheel.

I use 6 and 7 speed Freewheels , the over shift is slight.

with recent freewheels the tooth profile is Ala Hyperglide
and the chain is over eager to jump
when the side ramp on the next larger cog picks it up.

bobotech

I imagine that if worst came to worst, you could cut a slit on the end of the handlebars where the barcon is inserted to. That should release the tension however it would destroy the handlbars. Just a worst case scenario though.

FBinNY 

Long before the OP got that desperate, he could use a 5/16" drill and drill out the center of the expander bolt. That will weaken it enough that it will snap if he twists the body or puts a dull chisel against it's back and gave it a shart rap.

Drilling may be the best "last resort" option if he decides the nut is toast anyway, but I'd hold off until a replacement bolt was in hand. Until then I'd make every effort to get apart intact.

Phil_gretz

Fietsbob gave you the right hint, I think. Older freewheels (like SunTour) didn't have the twisted and tapered teeth that make shifting more rapid. So, you'd have to push the derailleur/chain pretty far over the next cog for it to jump.

Shimano Hyperglide and equivalent freewheels will speed the chain movement so that it'll jump before you really have the shifter into position. I find that this is true for Barcons and for downtube shifters. I often have to keep moving the shifter into position to prevent derailleur rubbing from an undershift with these modern freewheels, as the chain had already left. So it's move lever, hear the shift, continue to trim the shifter to quiet down and center the pulleys on the new cog. All of this becomes quite intuitive, by the way.

And once you internalize it, you never lose it, even 35 years later... PG

bobotech

I'm thinking though from a viewpoint of a guy who works at a coop. Bar end shifters are a very desirable rarity at coops on the other hand, common alloy bars are well, very common. We sell bar end shifters for roughly 20-30 dollars. Alloy drop bars are more like 5-10. It would make more sense to sacrifice the handlebar and save the wedge bolt (not too easy to find on a spur of the moment) rather than destroying the wedge bolt.

JeffOYB

I tried a Torx 40 and it didn't bite then I brought it to LBS and they tried a Torx 45 and it bit! That worked. So Torx in rounded-out allen bolts seems like a good idea!

About the barcon performance, I wiggled the derailler around and there was a fair bit of slop. Maybe that's it. I've installed a tighter (old) Shim Altus LT instead. Now to reinstall barcons and see what happens. It's an old 6-sp freewheel and old chain but without stretch. (In my test runs of the new derailler, etc., on my CX course the chain is sometimes bouncing off the "untrapped" lower pulley. Hmmm. I'll try shortening chain. Any other ideas?)

Thanks all!