# Please Help!!! I broke the bottom bracket lock ring!



## Bart (Mar 4, 2004)

Please Help!!!  
I broke this bottom bracket lock ring while trying to remove the bottom bracket.
It's made of plastic! The one at the drive side is fine but too tight to remove.
Any suggestions what I should do with this? or I better take it to the bike shop?
Also, anyone knows the bottom bracket size for 01 Specialized Stumjumper M4 Comp?
Thank you!


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## Haroow (Mar 10, 2004)

Bike Shop.... that sucks... maybe go with a S-h-im anal BB square taber if you can get one...or if you have the dough go isis or octlink...and get new crankset.... .03


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## ToddM (Feb 3, 2004)

Yep, sadly this is the crap shimano is making now for the square taper BBs. I was going to get a un-73 BB the other day seen it had a plastic non-drive side threaded cup and gave it back to the guy. If the plastic ones don't break like yours then end up stripping over time or the teeth break off.

About your only option if you can't get it out from the drive side (usually it's easier on the non-drive, but obviously that's no longer an option), is to take it to a shop and hopefully they can get it out using the drive side with a larger wrench or more arms on it. Also just in case you didn't know the drive side is reverse thread so you have to have a ratchet set to tighten to loosen it, that could be your problem. 

When you get a new bottom bracket either find a older un72 or 52 with the threaded metal cups on both sides, or get an FSA bb, or someone else's design with metal cups.


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## supercorsa (Jan 18, 2004)

nashbar offers a taiwan manufactured square taper cartridge bb with aluminum cups on both sides.

http://www.nashbar.com/profile.cfm?...rand=&sku=2288&storetype=&estoreid=&pagename=

cheap, but looks to be well made. the one i picked up for a commuter project had a slightly boogered cup (lip bent a bit) but nothing that 30 seconds with a file couldn't fix. the cartridge unit itself seems comparable to a un52/un72. they are definitely on my "i'd buy one again" list.

-eric

oh yeah, as far as removal of the pieces goes; pull the cartridge out from the drive side. make sure you're cranking clockwise to remove it, as english bb's have a reverse threaded drive side cup. once the cartridge is out there will no longer be any pressure on what's left of the non-drive side cup, you should then be able to spin it out with your fingers.

good luck...

ps: for what it's worth i've never had an issue with the plastic cups. i was exceedingly skeptical with the first one i encountered, but i've had no problems to date. my methods may account for this perhaps, as every bike i build gets fully reamed/faced/tapped before anything goes on it. as well, i liberally grease the threads in the bottom bracket shell, the threads on the cups themselves, and the cup/cartridge interfaces before installing a cartridge bb unit. it could be that rough or paint clogged threads in the shell generated enough additional friction that you snapped the lip off. check your threads closely once you get the pieces out, if they look at all suspect take your bike to a shop and have 'em chase the threads with a bb tap set.


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## Lab Worker (Mar 22, 2004)

ToddM said:


> Yep, sadly this is the crap shimano is making now for the square taper BBs. I was going to get a un-73 BB the other day seen it had a plastic non-drive side threaded cup and gave it back to the guy. If the plastic ones don't break like yours then end up stripping over time or the teeth break off.
> 
> About your only option if you can't get it out from the drive side (usually it's easier on the non-drive, but obviously that's no longer an option), is to take it to a shop and hopefully they can get it out using the drive side with a larger wrench or more arms on it. Also just in case you didn't know the drive side is reverse thread so you have to have a ratchet set to tighten to loosen it, that could be your problem.
> 
> When you get a new bottom bracket either find a older un72 or 52 with the threaded metal cups on both sides, or get an FSA bb, or someone else's design with metal cups.


What's wrong with plastic cups? They weigh less, will never corrode to the frame, and will not creak. A plastic cupped bottom bracket should never have any problems, as long as its correctly installed. Clean the BB threads, chase them if needed, face the frame if needed, apply some grease and only do the cups up to the recomended torque.

Before you try to get the driveside cup out make sure you remove the small bolt that might be under your bottom bracket holding the cable guide to the frame. Sometimes the bolts on these guides can be long enough to wedge the bottom bracket.

To remove the BB from the drive side, if worst comes to worst you can use a tool with flats for a large socket. I think Lifu make a tool that has 6 flats for a 32mm wrench, but a 6 or 12 point socket fits over it very well. Bolt the tool to the bottom bracet spindle with whatever bolts and washers you can find (this will stop the tool slipping), pop the 32mm socket into the rattle gun, and off you go.

Once the BB is out you should have no problems getting the plastic cup out. Again, if worst comes to worst you can (very carefully) hacksaw two slits into the cup (going from L to R in the frame) and remove the two plastic halves.

The BB for your specialized should be 68*113.


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## ToddM (Feb 3, 2004)

What's wrong with plastic cups?......see the above pictures. Not the first one I've seen that way. Granted maybe some shop monkey ham fisted it, or there was a lot of crap in the BB threads, or it was just a defective cast/mold batch, ever seen a AL BB cup do that? I doubt it. On top of that the few I have played with with plastic non-drive side cups when tightened to torque specs the plastic cup seems to introduce some friction to the BB spindle, it's not much and it may go away with time but it's slightly noticeable compared to a AL cup.

As to your arguement about not creaking or corroding to the frame, a properly installed AL cup will not do that either. Weight......I suppose there are a couple grams difference between the two for the real weight weenies. Also since the drive side is still AL it doesn't really fix any of those issues as it can still happen with the drive side. It would be intersting to see if anyone experiences compression of that cup over time causing some BB slop since that area would be about the highest stressed drive component of the bike, I highly doubt it though.

I agree that if properly done there should be few problems with them, and it's probalby not a huge issue since one isn't exactly pulling the BB out all the time. However all you have to do is have one shop monkey do it wrong (and few of them do it right), or just slip with that BB tool once and that plastic cup is done. How many shops pull out the BB and face and chase their BB's on new bikes from major manufacturers that come mostly pre-assembled, few to none. Most around here don't even have the tools to do it on bikes they build up, and if they did you wouldn't want them anywhere near your bike with a thread chaser or face ream. The Al cups are more reliable and a better design, period. 

About the only real advantage I could see to the plastic cups is that if cross threaded they probably would not damage the frame threads. However again it doesn't do anything for the drive side cup which is still AL it's only a 50% fix. And since we are assuming the person reams/faces/chases the BB and greases the threads and installs it properly that's not an issue.


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## Lab Worker (Mar 22, 2004)

I agree that in most cases an aluminium cup would be better, I just don't like people jumping on the anti-Shimano bandwagon because its cool, or seeing people complain about a product because they lacked the intelligence, tools or common sense to install it correctly. If the gentleman above did not install his BB himself then I do feel sorry for him.

I certainly don't like the spongy feeling that plastic cups give when you're trying to undo the last idiots work. Having said that though, I’ve seen many an aluminium cup’s tool surface become rounded out because someone though that using the extra-long breaker bar and some locktite to install the BB was a good idea. To get rid of the creaking in my BB all I have to do is tighten it, right???

Choosing to buy a more expensive Truvativ or Taiwanese made Raceface square taper BB over a plastic cupped UN5x or UN7x doesn't make a lot of sense to me....generally a Shimano BB goes into the bike and comes out many years later when its finally shagged. No you can't adjust them, no they are not cool, but they last well in most non DH/FR bikes, and they generally cost less than most.


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## ToddM (Feb 3, 2004)

All good points, I suppose I am kinda of nit-picking, while I prefer the al cups, if done right and care is taken the plastic cup should work fine as well. I've seen those rounded out AL cups too, along with the tell tale blue loc tite residue on the threads. Like you said too often the first answer anyone thinks of is it must have to be tighter.

I don't hate shimano they make some very good parts, in fact their BB's are some of the best deals out there at $20 and they last pretty well forever if installed correctly. I know I've had some last 5+ years with no issues. They make a lot of good parts, their cassettes are tops, they are the standard for front rings that everyone is compared to. 

If everyone took the time to do quality work and install things right and use some common sense with most of these parts they'd last a lot longer than they do. They'd probably also be cheaper since there would be less warranty replacements for improper install, and lets face it consumers pay for that in higher prices. Unfortunately most of the time you never know if the guy that installed them had any clue or care. We've all no doubt seen things done that should have never been done to bike parts. I seen one the other day where someone had put a shimano octalink on with the splines miss aligned and got it half way on before they figured something must be wrong.....ruined a crank and BB. There's no part made that will keep people like that from messing it up.

One reason I like to build bikes up from the frame, it costs a little more sometimes, and can take a little longer, but you know everything was installed with care, and hopefully done right. At least if it wasen't you have no one to blame but yourself.


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## Lab Worker (Mar 22, 2004)

ToddM said:


> A I seen one the other day where someone had put a shimano octalink on with the splines miss aligned and got it half way on before they figured something must be wrong.....ruined a crank and BB.


Hows this one:

Got a warrenty recal notice from of the the largest bike makers here in NZ the other day. On a large percentage of the mid to high end road bikes there had been some issues with the recessed nut holding the front brake to the fork. We were asked to check all our floor bikes and contact customers where we could. Somewhere along the line the wrong length nut had been used, and on one bike I checked the front brake was being held to the fork by 1.5 threads!! Whoever assembled the bike didn't seam to notice that the nut tightened up in 1.5 turns.

Or the guy the other day who covered both disk brakes in motor oil because they were sqeaking. This happened twice this week.

The right idiot with the wrong tool can destroy anything.


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## Bart (Mar 4, 2004)

I finally took the BB off from the drive side. Thanks


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## jonowee (Apr 8, 2004)

Now why in hell would anyone make something out of plastic for such a high stress area (your lard arse is crashing down when you're standing on your pedals)? %-|
Even if it made of polycarbonate (Lexan), it's only going to last 3-4 months -> one ride for most MTBikers.
Plastics on MTBikes should be limited to not mech. things like saddles, bottle cages and ahh... that's all I can think of that I would like my bike to have that's made of plastic. Use carbon fibre metal matrix, steel, aluminium or magnisium but plastic, you have to be joking! 

Respect, jonowee


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