Has anyone used the thread repair method?
 

A guy I work with is a roadie from BITD who still has his old Schwinn 564. He is a respectable and knowledgeable fabricator who I have developed quiet a bit of respect for over the years. We have talked about his riding days, his seemingly regular century rides. I was surprised that there was someone in rural North East Tennessee that was riding clipless in the 80's.

Long story short his bike has the rear DR hanger/drop out striped and he has asked me to go through the bike and get it back into riding shape. Obviously, I like the guy and was more than happy to take on the task for a future riding buddy. The problem is that the hanger isn't the most meaty thing in the world. I made some steel inserts at work, planning to bore out the drop out and press the inset in but I don't think there will be enough meat left once it's bored.

I searched and the repair that uses the smaller drill that I've found is this kit. Has anyone use this or similar components to repair a striped dropout?

I was going to order it but thought I'd post up here to see if there was any opinions on this repair process or this type of kit. I only need it for the one frame but it would be a good item to have on hand. If it works at all.

I've used it, but not on a bike. Should work as not much material is removed to drill/retap the hole.

Perhaps something like this might be easier?

http://i.ebayimg.com/00/s/MTYwMFgxNj..._id=880000500F

I have done a few Helicoil repairs and some "T" nutted ones ("dropout saver"). The Helicoils were always a bit tentative in the process. More fabricating skills needed but less material removed from the hole/hanger. The thicker the hanger the better a Helicoil is likely to be. Andy.

I have dealt with thinner hangers by putting a fillet of "filler epoxy" made for metal around the portion of the helicoil that extends past the back of the hanger.

I am a big fan of Helicoils (I specify them in new components) but I think the Dropout Saver is a better fit in this case. Just measure the dropout thickness and get the appropriate size.

The steel inserts I made at work are like the dropout savers that's been offered as a solution in this thread. I made them to .500" OD planing to drill and ream to .499" and press it in. The width of the DR hanger at it's narrowest point is right at .625. That's only leaving about 1/16" per side (the dropout is about .280" thick) which will be a very weak point. Using the kit I linked only requires a 10.3 MM drill (.405"), that brings the material left around to DR screw being almost twice as thick and much stronger. That's the appeal of the heli-coil style repair for me, I was just asking if people had had success using heli-coils to repair the DR hole.

Requires a bigger hole to be drilled in the derailer hanger.


If you can afford to lose that material, fine.
If you don't, not so fine.

Haven't used them on dropout hangers.
But I am a big fan of heli-coils as such.
BITD I built bindings for alpine snowboards, and made considerable use of aluminum stock, grub screws, countersunk screws and Heli-Coil.


Only issues I had were if the base material - the hole - wasn't deep enough.


It's possible to trim an insert down to fit, but they were more likely to slip under reverse torque.

We use both Heli-Coil wire inserts and EZ Lok steel inserts here where I work, depending on the repair. Each has it's own pros and cons. Obviously my first choice was the steel insert but my noted concern is ending up having a too fragile of a hanger in the end. I really didn't know what the twisting motion of the RD would do to the wound wire insert.

Please note that the kit in the original post lacks the tool needed to properly insert the Heli-Coils; this can be easily made from a screw if needed.

Yes, duly noted. I expect a 3/8 heliocil tool to be close enough to work on the M10. The real appeal of that kit is the M!0-1.0 STI tap. We don't have one and to source it from somewhere in the US would probably be twice that of the China kit.

I thought about having one of the insert's I made turned down but the reason I went with .500 OD was because we have .001 under reams. I expect I could safely turn down one of the inserts I made to .440-.450 but getting a press fit hole with just a drill is hit or miss, loctite can only do so much.

Ironically, the guy who owns the bike is a fabricator and lays down beautiful TIG welds but the paint on the frame is pristine and we are hoping to not have to heat the frame destroying the factory paint.

just go with the heli coil. they are legit. if that doesn't work go with one of the press fit options or the dropout saver. usually the helicoils are too long so you need to clip a few coils to shorten it. http://henkeladhesivesna.com/blog/ho...-wont-retract/

I will second dsbrandtjr's endorsement of helicoils. They are used in such things as racing cars to repair worn threads. You clearly have the tech skills needed for either the drop-in bushing or the helicoils (judging by your intention to ream within 0.001 for an interference fit). I kind of like the helicoils because you leave more metal on the hanger.

And as reptilez points out, if the helicoil doesn't hold you can go to the dropout saver as plan b. And if the helicoil fails in a way that the hanger breaks and is toast, the dropout saver would have failed in the same way.

MSC direct for $17.57 if you want one quicker: https://www.mscdirect.com/product/details/99092124

Recently I rebuilt/painted an 05 Specialized that used a chain ring bolt to attach the derailleur to the hanger.

Ah, clever that. Kind of like your own McGyverish hanger saver. But wasn't the OD of the bolt smaller than the bore in the derailleur body? How did you get that to match?

I'm guessing that you mean a chainring bolt to attach the hanger to the frame. I have seen that, but not what you describe.

One option is to rework the bolt in the derailer to M8.
Then you can use a solid insert with a smaller OD, and less material removed from the derailer hanger.

Opps...you are absolutely correct. Nevermind (Roseanne Roseannadanna voice)

You're old enough to remember Roseanne, but your sig file quotes Nickleback. Hmmmm. :foo:

Got hooked on SNL at the beginning and never gave up Rock music. Wife gives me a hard time for the "dark music" I listen to, to this day. Much harder than Nickleback. :D

I did a cross-country trip with my son in his pickup when he moved West. Never had listened much to Drake before.:eek:

I'm more of a Rachmaninoff Vespers type of guy.

My son calls his music "Aggressive". Uh huh.

I looked at MSC and didn't get that in the list of STI taps, thanks for the link.