Unicornz0

I noticed my bottom bracket is loose on my recently purchased 2000 Enduro with E type FD. I removed the crank and torqued it. Then I decided to take the BB out and do it right. I noticed that the previous owner used some type of black thread repair compound on the BB shell (look closely at the picture and you can see it in the BB shell). Now after thoroughly cleaning the BB shell the BB will not tighten down. If I remove the E type FD from the BB the UN-72 will tighten down, but not with the E type FD in place. Does anyone know of a BB with longer threads than the UN-72 or a suitable thread repair compound? I might try Loctite Form-A-Thread Stripped Thread Repair Kit, or just strip the frame and start from scratch and buy another frame. All help is apprciated.
Thanks in advance,
Uni

Stripped Bottom Bracket Shell

operator

Can't see anything with that fuzzy picture. If that bb will stay in place without the FD bracket spacing it out, i'd suggest upgrading the derailleur to a clamp on type $20-$30. Rather than tossing the frame.

I'd also suggest using blue loctite on those threads on reinstallation.

Bianchigirll 

I agree. get a different derailluer and clean all the threads then install with locktite.

operator

The e-type f.d mount margin 1-2mm given doesn't make it sound very hopeful for a save anyways. You might as well try.

Unicornz0

Thanks, there's an alternative I didn't give much thought. That down tube is pretty fat, 35-36mm. Any suggestions on a suitable FD? I'd really rather swap FD's than trying thread repair goop.

Unicornz0

Now that I'm thinking about it, If I can't find a FD to fit (I think I need a top pull 35/36mm), I'll run it without a FD and just use the middle or large chain wheel. When re-install the BB , I should just use blue Loctite on the threads, nothing else?
Thanks again,
Uni

davidad

I don't know if this will work with your deraileur. Might be worth a try. https://www.biketoolsetc.com/index.cg...ckets&tc=&q=&s=

operator

The cheapo shimano tourney (I *think* it's that one) is 34.9, includes shims to go down several sizes as well. Shouldn't cost more than $25.

Unicornz0

Thanks Everyone. I looked into all the alternatives mentioned, and I've got some good options. I also looked at the loctite Form a Thread.reviews. Seems like that goop is pretty good after all. I plan on trying that 1st. I'll post back after I try it, and let you all know how it worked.
Thanks again,
Uni

Airburst

You might try one of these, or something similar

https://www.sjscycles.co.uk/src/froog...eads-16505.htm

I've no idea if they work, but it might be worth a try

Sci-Fi

Problem Solvers E-Clamp might work if your tubing isn't oval:
https://www.jensonusa.com/store/produ...+E-Clamps.aspx

Unicornz0

Thanks again to everyone and also to Airburst and Sci-Fi.
My options are continuing to expand and I appreciate the help. I think I will be able to salvage this bike after all.
I will post my results as I try the various options that you all have kindly shared with me.
I have cleaned the BB thoroughly and expect the Loctite Form-a-Thread to arrive tomorrow.
I'll post my initial results tomorrow as long as I'm vertical and not horizontal..

larry_llama

The YST threadless BB are cheap and they work. Longevity might be an issue but I have had one on a commuter bike for years with no issues. At that price you could buy a spare to keep on hand.

The YST allowed me to save a nice old cannondale hand me down frame from the trash!

Unicornz0

Thanks so much, this is encouraging!

operator

Longevity is an issue.

We serviced primarily commuter bikes at our old shop and install these plenty of times, they don't last long 1-2 months in winter conditions under normal riding conditions.

Bianchigirll 

Velo Orange is coming out with a nice 'threadless BB real soon if it is not on their site already.

https://www.velo-orange.com/index.html

Unicornz0

Hi Bianchigirll, it's not on their site yet. I'll check with them about it.
Thanks so very much.
Uni

Unicornz0

Do these threadless BB install without any preparation to the remaining BB shell threads, or is some preparation needed prior to installation?

Thanks

Unicornz0

I've got a good start to the day. The Loctite Form-A-Thread arrived early today. Really quick shipping and a very reasonable price from Summit Racing Equipment in Ohio. This Form-A-Thread process is really easy but not what I expected. After applying the compounds as directed and screwing the BB into the shell, then waiting 5 minutes (fortunately I used a timer), the BB was so very tight. I almost was not able to remove it. Even though I did not torque the BB when screwing it in. As I was trying to unscrew the BB it would only spin and not back out of the shell. There were some blocks of wood nearby that I piled under the non drive side of the BB and cup, put pressure on the frame while unscrewing the BB. If I would have left the BB in the shell for more than the 5 minutes, I probably would not have been able to remove it.
Now it has to cure for 2 hours. It seems very promising. I'm supposed to be able to torque it well over a 100 ft lbs. Hopefully it will hold up under the initial torque and the various pressures of mountain biking.
I'll let you all know how it works out.

Thanks again,
Uni

operator

You don't need a chamfering tool if that's what you're asking. The YST just goes in like a normal bb

Unicornz0

Yes, I wanted to know if they installed just like a regular BB. I plan on trying a threadless BB next if this Loctite product doen't work, unless I find another frame.
Thanks

Unicornz0

My hopes for a quick and easy repair have been dashed. The Form-A-Thread did not allow me to torque the BB. If I would have left it in during the curing period, maybe it would have worked for a while. I looked in to the threadless BB, and I'm not going to go that route, one has non replaceable bearings, and the YST has ball bearings.
Thanks for the help,
Uni

BCRider

You may want to try the FormAThread again. But remove the BB a hair before the 5 minute mark where it tightens up or slightly later when the bond to the shell is slightly more complete. In your post about it you mentioned that it spun at first and then you were able to get it to come out. That spinning implies to me that you broke the bond that was forming even if you did manage to get it to come out following that point. Either way the bond was broken and obviously it didn't cure correctly to full strength from there.

Was the BB shell well cleaned and fully degreased using something really good like brake cleaner or wax and grease paint prep? Doubly and triply degreased? Even the lightest of films will potentially ruin the bond. And finally it may or may not help but a doubled application of the release agent to the BB threads might aid in the BB coming out more easily and cleanly. Perhaps wait for the release agent to dry for a while longer?


The oddball thing to this is that I just found the same issue on my old Canondale touring bike. It took me about 10 years of riding to ruin the threads but they are sure gone now. I just found this out two days ago when on a grocery errand ride. I was just coming in to the forums to see if a search would turn up any options and found your thread. They say troubles come in threes. I wonder who else will turn up with the same stripped BB theads issue....

I was contemplating setting my frame up in my mill drill and bore out clearance to press fit a sleeve with yellow loctite that I'd make out of stainless with new threading. These old style late 80's vintage Canondales have such thick BB shells that this is a realistic option. But the Form A Thread would be a lot less work if it stands up.

I can't say for sure yet but I think part of the issue was a combination of a poor original thread fit and a lack of proper support in the sleeve on the non drive side. I noticed that the NDS had some vertical float in it where it SHOULD have been a snug fit in the sleeve. This means that the forces on the NDS were levering against the threads on the DS instead of being separately supported. With the poor initial fit on the DS threads I'm pretty sure it is what led to the final total failure of the DS threading. Any repair I do will involve testing for this and shimming as required to ensure the NDS sleeve supports the BB fully and firmly. And I'd suggest that you do the same if you manage to get a good thread to take.

DMF 

It does? The fact that it spun in place (again) tells me that the new threads are ruined too. Or there was never enough material to form them properly. (Maybe it squeezed out?)

Don't they say something about greasing the "template" before screwing it in?


Edit: Oh, I see the result. I'm with BCRider. Try it again, and get the BB in quickly while the stuff is still at its loosest.


Btw, condition is the BB threads in?

DMF 

Well that nails it. I'm not removing a BB until someone else's strips out!