[yogie]

The right hand side of my b/b is partially stripped, I was wondering if anyone knows of a good way to replace the thread. I am going to try lusing ocktite bearing-fit to hold it in, but would like a more permanent fix. I was thinking of getting some thread repairing goop, or maybe trying to get it heli-coiled.
Has anyone else had experience with this kind of issue?

 

[-dustin]

take the frame to a shop...the might be able to rechase it (or is it called reface?...i don't know).

oh...wait...the BB, or the BB shell?

 

[oldfart]

Ou. He's talking bb shell because you can't helicoil a bb cup. I suppose there is a helicoil big enough but I've never seen or heard of one. I suspect there isn't one. The first thing is to get a shop to chase the threads. Depending how bad it is that might work. Another option is to search out an old Mavic bb which did not thread into the shell. The lockrings held it in place. Requires putting a chamfer on the faces. You could potentialy ream out the shell and rethread in italian thread which is larger diameter and put in an appropriate italian threaded bb. If you've got a wide shell, the 73mm , then maybe face it down to 68 and thread it in a bit further. Often its just the outside threads that get buggered. Most people stop when the bb is hard to thread in further.

 

[-dustin]

what's heilcoil?

 

[yogie]

its pretty buggered. you can push the bottom bracket in by hand (without turning it). i'm using a 68/118 shimano bb, which doesn't have a very long thread section. i might see if i can find a bb with a much longer thread section. i didn't think a helicoil in that thread size would be very common. i've given the bearing fit loctite a couple of days to set, so i'll see if it holds. the italian bb size sounds promising if the loctite fails.

a helicoil is a coil shaped thing which replaces the thread. you ream a larger thread into the hole of interest, and then screw in the helicoil, which gives you a thread of the original size. i doubt that they make one in a reverse thread for the right cup of a bb shell. : (

 

[RideMonkey]

I've seen a helicoil in BB threads. Many years ago though and I couldnt tell ya where to find one now.

 

[rfemurfx]

sorry yogie, you can not turn your bb into an italian bb. and if you do manege it then the only bb's youll find to fit would be road bb's. which if you happen to have a shimano splined crank it may work out. if your frame is steel then you can send it to it's builder to have the bb shell replaced, or if it's Ti. but i suspect it may be Aluminum, sorry sounds like what you are trying out it's your best bet.
by the way, what caused it to strip out so bad!?

 

[yogie]

bought the bike second hand, the guy that owned the bike before me must have ridden it loose or something. it doesn't look cross threaded, its just that the top of the thread has been pulled out.
i'm thinking that the bearing fit goop should fix it. i've seen it do wonders for a loose headset cup on a friends bike. and there are a few different thread repair substances you can buy.
if the loctite doesn't work, i'll probably get a bb with a longer thread section.

 

[sub6]

Have it tapped for a 70mm BB. 70mm bbs have a larger diameter thread; 68 and 73 are the same; 70 is a little bigger. Hopefully, there isn't so much metal missing that you can't get a 70mm's threads to work.

Granted, you'll be limited to using only 70mm BBs, but there are plenty of UN-72s in that size floating around. You just have to look a little harder - it's a better option than junking the frame, IMHO.

 

[yogie]

The bearing-fit loctite is holding it in so far. I've ridden it about 4 times since bonding it in there. Hope it holds.

 

[Dave]

if all else fails you could epoxy it in there, that is better than junking the frame, just dont plan on replacing the bb after that.

 

[dbisers311]

I partially stripped the non-drive side of my bb shell on an old barracuda frame. I cut a a shim out of a beer can, put it in between the bb cup and the crappy threads on the bb shell and just torqued it in there, making the shim into a half-assed helicoil. It worked great from there on.

 

[PBbike679]

get it done to an italian BB. FSA has a mtb BB thats ISIS for this problem. I did it to my fuel and i got it italianized and it works like new. i even can sell you my BB since i dont use it anymore, 1 season old. sealed bearings, ISIS. (i guess thats spam, but im just trying to help the guy out

 

[JRogers]

Whoa....back from the dead

 

[DßR]

wow, and to think I almost posted in this thread AGAIN 2.5 years later...

 

[ioscope]

The frame is old, get a new one!

 

[caputo1989]

All I can say is go to your shoop and have them re tap the shell it does work ive done it before. DONT TRY TO BUY A TAP UNLESS YOU WANT TO SPEND $500 ON ONE.

 

[Dirtbike]

All I can say is go to your shoop and have them re tap the shell it does work ive done it before. DONT TRY TO BUY A TAP UNLESS YOU WANT TO SPEND $500 ON ONE.

HOPEFULLY HES GOT IT FIGURED OUT AFTER 2.5 years...

 

[binary visions]

HOPEFULLY HES GOT IT FIGURED OUT AFTER 2.5 years...

Considering the source, he may well have spent two and a half years working on the solution

 

[Matrimony]

lmao, I love these kinds of threads!

 

[jinshiyang]

Requires putting a chamfer on the faces. You could potentialy ream out the shell and rethread in italian thread which is larger diameter and put thread insert helicoil
http://www.xhcljx.com/eng