Rear derailler hanger threading issues

[ian m]

I have a first gen Clem, bought as frame and built up in 2015. I don't remember if I had issues installing the derailler at that time, and I haven't removed it since. HOWEVER, tonight I had a bear of a time getting the derailler back on and am worried I completely chewed up the threading. It really felt like they were made of soft clay. Anyway I'm now dreading a future replacement of this derailler. Can I get the threads retapped without changing the size? Anyone have experience with this?

[Ray Varella]

Is it cross threaded?
Did the derailer seat nice and square to the dropout.

Ray

[Tom Matchak]

Wheels Manufacturing makes an insert for replacing stripped derailleur hanger threads. Called a “Dropout Saver” or “Derailleur Hanger Saver”, it is widely available, at about $22 for a pair. You drill out the damaged thread with a 15/32” bit, slip the flanged and threaded insert into the hole from the back side, and attach the derailleur as normally done. Been around forever, works great.

Cheers,
Tom Matchak

[Joe Bernard]

If it's in there tight and straight I think you're ok. I've owned/fiddled with a few of these frames and always find that hanger to be a bugger. I think the paint is thick in there and you sure feel it screwing the derailer in, I've scared myself a few times thinking I've done something wrong.

There's probably a tap you can buy to clean the threads before installation, but I know nothing of such matters.

[ian m]

I don't believe it's cross threaded, at least not all the way through. Derailler is, or seems to be, flush with hanger. The main problem was the first quarter to half of the threads, the hanger bolt couldn't get any purchase on the hanger threads, and as I backed it out about 2 dozen times there would always be some metal shavings on the hanger bolt. Guess I'll find out the situation when this derailler bites the dust!

Tom, thanks for the suggestion. Glad to hear something like that exists!

[Ian A]

Probably worth chasing the hanger through with a tap. Your LBS or co-op will have the 10mmx1mm tap needed.

Make sure the derailleur is not going to pull out of the threads - it's under quite a lot of force from the derailleur spring. I had one pull itself out of what seemed to be compromised but okay threads and launch itself into the back wheel. Broke the derailleur, bent the hanger and even after rebuilding the wheel, left a hop in the rear rim.

I used a Problem Solvers "drop out saver" sleeve and it's been fine ever since. When drilling out the threads, I actually used a round file and made the hole a fraction undersize to achieve a press fit.

The sleeve is not a perfect solution as it can protrude enough to interfere with the smallest gear depending on clearance. I had to file the dropout saver flange a touch on my bike to clear the 9th cog in 130mm OLN spacing (not a Riv).

IanA

[Nate in Oakland]

Haha! I was changing the rear derailleur on a 1st gen Clem last night and had the same concern. Glad to know I’m not alone!

Nate