aaronmichael

Hello bicycling friends,

I work at a LBS and have a bike in for repair that we have a tricky situation on. This is definitely not the first time this has happened and probably won't be the last. We were replacing cable / housing for the front derailleur on an older Specialized and the barrel adjuster on the downtube would not turn. We gave it a slight turn with a pair of pliers and the thing sheared right off due to corrosion. Despite trying some penetrating fluid, we had no luck trying to twist it out of there. I'm thinking the only option now is to attempt to drill it out. Even if we ruin the threads in the integrated frame part (it's riveted to the frame), we can still use it as a stop and add a in-line barrel adjuster. Of course the frame is not round so we can't add a clamp on cable stop. Any advice would be GREATLY appreciated, attached a couple photos for reference. Thank you!

Iride01 

Unless you have a really long drill bit and are good with your aim, I doubt you'll drill that straight enough while it's on the frame. Drill out the rivets and then try to drill out the remaining part of the barrel adjuster. Maybe also hunt around and try to find another stop like that. Ask Trek. Or look for a old trashed bike frame that has a working one on it and get that.

aaronmichael

Yeah, my hopes are not high for drilling it out while on the frame but I don't see many other options. My hesitation with removing the stop from the frame is that the frame is carbon and our shop doesn't have any experience doing frame repair. Trying to avoid outsourcing it but that's what it may come down to.

Crankycrank

Try a sheet metal screw and run it through the top part of the broken Barrell adjuster. It will grab the hole in the adjuster and hopefully turn it. When you get most of the adjuster to screw out the bottom of the stop you can grab it with some pliers and remove the screw from the top. Use as large of a diameter screw that will fit so it's less likely to bend or break when turning. Put a little penetrating fluid on the threads a day or so beforehand.

Barry2 

That's likely the best idea.
Else, you risk digging yourself into a bigger hole.

Barry

grumpus

It's quite likely bonded as well as riveted so there's a good chance of at least damaging the paint. I've made ridiculously long drill bits for this sort of application by soldering a regular twist drill onto a length of cold rolled steel bar (using brass tube for a joining sleeve). Caution - only drill slowly, if the drill bit gets out of control it will whip around with some ferocity. I'd suggest making a guide for the drill that can be taped to the frame, and more tape to protect the paint.

Andrew R Stewart 

My first thought is whether the customer is in this loop. I've certainly had repairs go south more times than I am happy with and when the added service is a0 more costly, and/or b) potentially will affect cosmetics the cust needs to be part of the decision.

I like the repair suggestions already offered.

I'll add that the rear DT casing stop/adjuster is perhaps the single most ignored feature of so many bikes I have serviced. Very few wrenches and/or riders bother to a) remove and lube the adjuster barrel threads during cable replacements, b) even use that adjuster, as nearly every Shimano rear der has an adjuster built into the der. The left/front side adjusted is far less often frozen as it at least gets rotated every so often. Between the road spray from the ft wheel and body sweat from the sides of your legs these adjusted have a bad exposure to crap life. This is one reason why some very few adjusters are made of brass... Andy

Kontact 

In my experience this kind of fitting is not epoxied. You could drill out one rivet and rock it back and forth to see if it is bonded - put a new rivet back in if not.

Get it out, put it in the vise and drill it until the adjuster remnants falls away from threads when your bit is about the diameter of the top of the threads.


For a long drill bit, you can buy them, but you can also get hex shank drill bits and use an extension. All pretty cheap.

ScottCommutes

It looks like you have some room to work on the bottom side. Cut a slot with a dremel and get a screwdriver on it. Nothing to lose slotting the busted part.

dedhed

​​​​​​https://www.harborfreight.com/11-34-...hoC71YQAvD_BwE

​​​​​​https://www.homedepot.com/p/RYOBI-11...FB1G/205193137

aaronmichael

The customer does know what's going on but we always feel like this is our fault for trying to turn the adjuster too hard rather than just leaving it alone. Thank you to everyone for the suggestions. We don't feel comfortable removing the housing stop from the frame so going to do everything in our power not to let it get to that. I liked the idea about a sheet metal screw, sounds like it would have a lot of bite. Thank you dedhed for the suggestion about the flexible shafts, seems like it would be a great tool to make attempting to drill it out a little bit easier if that's what it came down to. Any more suggestions would be great!

JoeTBM 

Soak the hell out of it with PB Blaster, wait, and then try a left hand drill to get it to move out.
second thought is to hammer in a small sacrificial Torx bit, it should bite into the opening and then use a 1/4 head on socket wrench to back out

JoeTBM 

I like this, unusual that the Harbor Freight one is more expensive then the Home Depot version

ScottCommutes

Get a rawhide or plastic hammer and tap at all over a lot of times to break corrosion loose and facilitate PB Blaster soaking in there.

70sSanO

If you do get it out, but can’t thread in another stop. you may already have a solution going forward.

If not I’ve used Jagwire Sport Direct Adjuster in a number of spots. They were designed for external cable routed Shimano STI levers, but I’ve used them on RD’s with no cable adjusters, Suntour thumb shifters, most anyplace with a stop diameter that will accept a shifter cable ferrule.

John

aaronmichael

No luck just yet but have been taking it very slowly. I notched a slot in the bottom and tried to turn it with a flathead screwdriver but the two "tabs" just started to bend outwards. What do you guys think about using a screw extractor? I tried very briefly to use one with no luck but I did not put a lot of torque on it. Would I benefit from trying to use some heat? What about using the Finish Line "Chill Zone" product? Remember this is a carbon frame so I'm hesitant to use too much direct heat. Any additional advice would be great, thanks!

Mad Honk 

Do not try heat!! Carbon fiber will break down with the application of 350*F, and that can be achieved with a small butane torch. Worst case; you can perhaps file the edges clean and add an adjustor in line right above the new cable guide. Good luck! Smiles, MH

Kontact 

If you want to try heat, stick a soldering iron directly into the cable hole barrel. That will keep it local enough to not get to the frame, but should be enough to do whatever heat is going to do (or not).

A screw extractor used with a wrench might work. But if you want to do it with a drill, you're back to the problem of lining it up.

I think you're likely to drill the rivets and drilling the adjuster shaft out in steps, or replacing the whole assembly.