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a friend just stripped the bolt on his 3T Zepp. solution?(5 posts)

a friend just stripped the bolt on his 3T Zepp. solution?weiwentg
Jul 10, 2002 11:14 PM
I seem to recall someone mentioning that one could have the threads re-tapped with the next larger bolt size, and the Zepp uses 4mm face plate bolts.
anyway, he was doing the equivalent of JRA to the stem while adjusting his handlebars. he's no gorilla. funny, then, that this should happen.
Coil repair probably a better fixCalvin
Jul 11, 2002 4:08 AM
The thread of that stem is more likely a 5mm. The 4mm may be the wrench size. Double check this. A 4mm thread would be very small indeed for a stem.

There is a coil system by either "Helicoil" or "Recoil" that does tap the hole larger for a steel coil insert. The size of the bolt remains the same. A good shop should be able to do this for you.
re: a friend just stripped the bolt on his 3T Zepp. solution?dirthead
Jul 11, 2002 5:11 AM
I posted the response earlier about tapping the threads to a larger size. This can be done very easily, as long as the head of the larger bolt fits inside the recessed hole in the stem. The idea of using a helicoil will also work. The items needed to do either of these fixes can be found at almost any hardware store for minimal $$. I have personally tapped the threads on a stem to the next larger size, so I know this will work. The helicoil should work just as well, but I have never done it on an aluminum stem. The helicoil will require the hole to be drilled out and threaded to a specific size for the helicoil to fit into. The helicoil is basically a threaded insert, that is screwed into the newly tapped hole, and the stem bolt is then screwed into it. They are very strong and used in all types of applications.

Tapping the hole to the next larger size will cost about $5. Using a helicoil will cost a little more, maybe $10 at the most, since you will need the helicoil, thread tap, and some loc-tite.

Let me know if you have any more questions.
re: Is the bolt head stripped, or the threads??cyclejim
Jul 11, 2002 9:20 PM
If it's just the bolt head and the edges are simply worn off such that the allen key just turns, you can get a little drill bit tool from Home Depot that will do the trick. You drill a small pilot hole into the middle of the bolt, then drill the tool into that hole. It allows you to back out the stripped head, leaving your original threads intact and ready for a replacement bolt. Works great and I used it on my stem once already.
the threads, sadly. he sent it back to 3T in Italy. nmweiwentg
Jul 12, 2002 1:40 AM