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Stripped BB shell on 03 Stumpjumper FSR

J

jtast17

Chimp
Dec 30, 2006
15
0
Hey guys...I don't think I have ever posted to the forums here, but have been around for a year or so now reading, etc. I really enjoy being here on RideMonkey when I get the time.

Anyways, I ran into a problem today...quite dissappointed at the moment. I have an '03 Stumperjumper FSR comp that I tore down this winter and was doing a nice R&D on. A couple of years back, I went from an ISIS style crank/BB back to a square spline XT and UN-52 setup I had (to fix problems I was having with the ISIS BB always seeming to wear out quickly). Not to mention, I was never really a fan of that system. This square taper XT crank had never let me down, etc.

So, I go to take out the bottom bracket today, and everything went smoothly. No issues after breaking loose...however, looking at the non drive side of the bike, alot of the threads of the BB shell CAME OUT with the BB. I remember installing it, NO issues whatsoever, no cross threading, etc. However, now looking at the BB I'm missing alot of threads on the non drive side and am not quite sure what my options are.

Any ideas? I know I could take her to an Italian thread....is there anything I can do? Anyone have any ideas and/or have had this happen before? (the D side shell came out great as well...no thread issues). I'm really bummed and hope the frame isn't useless now!

A pic...



There is still good thread on the inside and i really honestly couldn't tell what happened. This sucks. If anyone can help or shed light on a repair, that'd be great....

Joe
 
ultraNoob

ultraNoob

Yoshinoya Destroyer
Jan 20, 2007
4,504
1
Hills of Paradise
The Bad News:
I don't think there's much you can do (repair wise) that will not compromise the structural integrity of that bb shell. Aside from getting a new shell welded in, and getting the whole frame re-heat treated, you may be stuck buying a new frame.

The Good News:
This is a great reason to buy a new bike!
 
J

jtast17

Chimp
Dec 30, 2006
15
0
I guess we will see. From the looks of the threads, it appears that more of the actual BB cup threads shredded...rather than the shell threads themselves...this is especially evident when I run my fingers across it...

I took it to the local shop in town, they said similar, but also that they didn't have the tooling to fix it, they suggested my contacting Oswald Cycleworks in the Mansfield, PA area (about an hour from here) to see if he could do anything.
I called, had a good conversation and also sent the same picture his way. He feels confident that he can repair it and retain the English threads as well. It'l cost be 100-125 to do, but thats better than a new frame.
A new bike would be great...but i don't have the cash to do that. I have to work with what i have.

Any other thoughts...opinions would be great.

Joe
 
J

jtast17

Chimp
Dec 30, 2006
15
0
thanks,

I appreciate that and still am looking for anyone else that has had a similar experience, etc. I did search...came up with a few hits on the forums here, but nothing with pictures or that much detail.
In one instance, it was a retap to Italian threads....
In another....interesting beer can/shim mod :)
Another, was that the shell just needed a rechase and what had appeared to be trashed shell threads was actually where the cup threads got eaten up and the shell was in "ok" shape.

Again, I'm really glad this is on the nondrive side of the bike. Any other comments and ideas, experience, will be great.

Joe
 
J

jtast17

Chimp
Dec 30, 2006
15
0
I'm going to read that link on chemical thread repair.
I really am looking at how I think alot of the threads that "appear" missing are actually there and what I am seeing is the BB cup threads actually just stripped out. Either way, they are embedded at the very least and it will need to be clean/reamed, etc. I'm going to take it to the shop this weekend. No one at the local shop had the tool to go through it. If i'm lucky, I won't have to leave her there for a week to get fixed...and its easier that I thought...hoped....we'll see

Just want to get it fixed...spring is calling soon I hope and a few new/used parts have arrived!

Joe
 
J

jtast17

Chimp
Dec 30, 2006
15
0
So, another update on this.

I ran the frame down to Mansfield, PA today. I took it to the shop I mentioned above, Oswald Cycleworks and they were great about helping out. I mentioned last week that I was going to take it there and had conversed a bit with the shop owner, etc. about what we could do. Took the frame there so they will have it for about a week before I'll get it back.
I have to mention to anyone...these guys are top notch...very nice, and build some beautiful custom rigs. Check it out at www.oswaldcycleworks.com if you are interested. They have alot of good info and some nice galleries of bikes.

SO, I guess this has happened to a frame before. No one is quite sure what happened...it may very well be my fault, but either way, its going to be fixed.

The options:
1.) The first thing that they are going to do is to take the non-drive side of the BB shell and TAP it for Italian thread. Then, they are going to use a sleeve, helicoil/insert of sorts that is essential an italian thread on then outside and the English thread on the inside. Thread this into the BB shell and locktite it in there for a finished product. I will then be able to use an English thread and it will be essential "new" with no ill issues, hard to find BB's etc.

2.) If for some reason they couldn't do this, they suggested that they would tap it out to Italian and I could run a modified ROAD x-type bb that they could press heavier duty bearings and seals into if I wanted them too. The suggested BB was a cheap Shimano 105 unit with the heavy duty bearings and new seals installed....however, they didn't see the need for this and think that option one will fix it up just fine.

Now the question is which XC crank I want to go with...since I'll probably go ahead and finally retire the good ole' square taper XT crankset I've been using for so long....

Joe
 
K

kuksul08

Monkey
Jun 4, 2007
240
0
You could put some filler in there to make it thicker and then re-tap the threads. It's not like they take a huge load or anything, they just need to hold the BB in.

I think surface welding would mess up the heat treatment of the frame in that critical area. Maybe some kind of strong and well-adhering compound would work.
 
J

jtast17

Chimp
Dec 30, 2006
15
0
I think I like the idea of the method that Oswald is going about to fix the bike. I know there are a number of ways that I could have done it "shade tree", but this is a frame that when i'm ready to sell, I'd like to sell with confidence, etc... Whenever that happens. We'll see, I'm anxious to get it back to start building the bike back up for the next month here.

I'm student teaching right now and I really needed to "relax" from the idea of school today and decided to attack my TALAS fork... it was pretty scuffed up, etc. and TALAS blue really doesn't go with the frame...so, I cleaned, sand, masked and re-masked the fork today and went to town with it. I'm super happy with the results, came out looking very professional and should stand up nicely to the elements.

Here it is 2 prime coats, 2 base coats and 3 clearcoats later!





Not the best pics...still working on using this new digi cam...fun.

Thanks for the responses though guys...got the gears turning.

Joe
 
K

kuksul08

Monkey
Jun 4, 2007
240
0
Ahh I didn't see that part about the helicoil...That sounds perfect. They shouldn't need to take out too much material either :)
 
BrooklynMachine

BrooklynMachine

Monkey
Sep 1, 2007
320
0
16 powers st BKLN NY
While it sounds like you have a winning solution, there is a cheaper option to try out before you resort to going Italian:

The YST "repair" BB is a cartridge BB with externally threadless cups that screw into the BB body internally. Basically, if your threads are stripped it pulls new cups and bearings into the shell and allows you to run a square taper BB.
It's not the most elegant of solutions, but it is cheap with street price averaging 20 bucks, and may be worth a shot.
 
J

jtast17

Chimp
Dec 30, 2006
15
0
Yeah, I saw that and such. In the interests of upgrading my crank though and going with an xtype unit, I want to try this and see. They seemed completely confident that the sleeve will work, that my situation isn't as bad as some that they have seen. It'll allow me to still use any English threaded unit and get away from having to run the square taper unit. Its def. time to retire that XT crank I've been using...

Joe
 
J

jtast17

Chimp
Dec 30, 2006
15
0
I am hoping that if they need to just chase the threads...that it is what they do. We'll see. Going to call the shop Thurs. or Friday...

Joe
 
B

booner05

Chimp
May 15, 2009
2
0
Also curious how this turned out because I received a bike with a cross threaded BB.

Welding on an aluminum frame (even to add material for threading) without re-tempering will make your frame much weaker (6061-T6 is ~3x stronger than untempered 6061).

If the BB shell is thick enough, could you have it machined to fit spanish BB? I thought euro has a 31mm pitch diameter while spanish bearings have a 37mm outer diameter?

Someone please correct me if the info I have here is wrong.
 
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