Bottom bracket - sealed cartridge removal fun

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I've been overhauling the mountain bikes, and figured it was time to tackle the sealed cartridges in the bottom bracket of each bike. My 3-season bike is a 2002 Rocky Mountain fusion, and I'd never had it apart. The axle still spun freely without roughness or any noise, but I figured it had to be time. This tool, with the splined socket welded to a fairly short bar, was ineffective for me:



Likewise, a separate splined socket on a breaker bar didn't do it either:


However, the same socket used with the impact wrench finally broke it free:


I don't know why they made the socket 3/8" drive, and I should get an impact-rated adapter.

I should add, for the benefit of anyone taking this on, that on the drive-side (i.e. R side), the thread is LH - that is, CW to loosen. (This seems weird to me, as the pedals are reversed - the LH thread is on the L side). But in any case, this is something to keep in mind.

I was able to take the Shimano unit in my bike apart, and repacked the bearings with Mobil 1 grease. This video by RJ the Bike Guy was very helpful:

https://www.youtube.com/watch?v=lar7mIMmTRE

My wife's bike (Giant Iguana, 2007 or 2008) uses the FSA cartridge, which appears to not be user-serviceable. No matter, it's still working well, and I'll just replace it when the time comes.

I slathered on the anti-seize when reinstalling both units.
 
Originally Posted By: Number_35
However, the same socket used with the impact wrench finally broke it free:...
I don't know why they made the socket 3/8" drive, and I should get an impact-rated adapter.

I should add, for the benefit of anyone taking this on, that on the drive-side (i.e. R side), the thread is LH - that is, CW to loosen. (This seems weird to me, as the pedals are reversed - the LH thread is on the L side). ...
If it was that hard to loosen, it must've been either grossly overtightened, or rusted? 3/8"-drive tools should easily handle the installation torque specified by Shimano.

The right BB threads and left pedal threads HAVE to be left-hand threaded, otherwise the BB might loosen in use, and the left pedal definitely would. Allegedly the Wright brothers get credit for solving the pedal-loosening problem that plagued earlier bikes. "Italian" threaded BB's don't have the left hand threading. The BB of my Italian-threaded bike has loosened two or three times in ~214k miles.
 
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Another option besides an impact is putting the bit in a vise and holding the bicycle frame. Not only do you have a longer lever arm but you have more than one. A Of course, that is awkward.

As a guy who works on old bikes and commutes on salted roads, you do what you have to do.
 
Originally Posted By: CR94
If it was that hard to loosen, it must've been either grossly overtightened, or rusted? 3/8"-drive tools should easily handle the installation torque specified by Shimano.

The right BB threads and left pedal threads HAVE to be left-hand threaded, otherwise the BB might loosen in use, and the left pedal definitely would. Allegedly the Wright brothers get credit for solving the pedal-loosening problem that plagued earlier bikes. "Italian" threaded BB's don't have the left hand threading. The BB of my Italian-threaded bike has loosened two or three times in ~214k miles.

Agreed, it shouldn't have been so tight. I've had the bike since new, and had never had it apart. I rode it to work for at least three winters, the last one 2006/07 - that takes a toll. I should have overhauled it at that point. Lesson learned - my next bike comes apart early on, and I apply anti-seize in the early going. I understand why the L pedal has LH thread, and the R pedal has RH thread, but why not have those same threads used on the BB? Instead they're reversed - RH on the L side, and LH on the R (drive) side. It seems to me that both would be prone to loosening. (By the way, thanks for the information about the Wright brothers - very interesting!)

214K miles? Wow! I figure I've put about 50K km on this bike - almost nothing by comparison to yours.
 
Originally Posted By: bepperb
Another option besides an impact is putting the bit in a vise and holding the bicycle frame. Not only do you have a longer lever arm but you have more than one. A Of course, that is awkward.

As a guy who works on old bikes and commutes on salted roads, you do what you have to do.

That's a smart idea! However, the splined system is not a great one - the interface between the splined socket and the bracket is iffy - it's very prone to slipping. I had the bike on its side and liked having the weight of the impact wrench helping to keep the socket's splines in the splined recesses in the bracket.

Dietary salt seems to do me no harm, but I bet my blood pressure rises whenever I fight with a rusted-in part.
smile.gif
 
Originally Posted By: Number_35
... I understand why the L pedal has LH thread, and the R pedal has RH thread, but why not have those same threads used on the BB? Instead they're reversed - RH on the L side, and LH on the R (drive) side. It seems to me that both would be prone to loosening. (By the way, thanks for the information about the Wright brothers ...
I can assure you from personal experience, as well as theory, that when (fortunately rarely) the RH thread of the right side of my Italian-threaded BB began to loosen, it unscrewed itself remarkably rapidly. That happened in the middle of a ride and I tried to make do by finger-tightening the loose cup. I couldn't pedal more than maybe half a mile each time before the right BB cup became extremely loose again.

Visualize the outer surface of a cylinder rolling without slipping against the inner surface of a slightly larger cylinder that's fixed in place. Each time the center of the inner cylinder completes one revolution, its outer surface rotates slightly in the opposite direction. Right? Essentially, that's why the BB cups tend to rotate slowly in the opposite direction from crank rotation. That can be a problem if the rotation is in the direction that loosens the threads. Therefore, "British" threaded BBs sensibly use LH threads on the right side.

I'm not sure how true the bit about the Wright brothers is. I read it somewhere, pre-internet.
 
Epicyclic rotation will cause the fixed cup to tend to loosen as you pedal. This is why a bicycle's left hand pedal and fixed cup are left hand thread.
(Unless it's an Italian bike, in which case the fixed cup tends to fall out.)
Bit of trivia: It was the Wright brothers who figured this out and adopted the LH pedal thread in the left pedal.

Absent the power, a generally sure-fire way to get that cup out is to hold the tool in place with a bolt and use a vise.
 
Originally Posted By: AZjeff
That's a well used bike. It looks like it might be one size too small.

Interesting - I never thought about the sizing, because I've always found it to be a comfortable bike. The rationale back in the day was to go with as small a frame as possible (for weight savings) and then to raise the seat and handlebars accordingly.

"Well used" - indeed. It's seen a lot of use, has had the rear wheel stolen, and has been beaten up by our bad roads. On the upside, when there was a rash of bike thefts at work, the thieves overlooked my bike in favour of 29ers, etc.
 
Originally Posted By: 853okg
Epicyclic rotation will cause the fixed cup to tend to loosen as you pedal. This is why a bicycle's left hand pedal and fixed cup are left hand thread.
(Unless it's an Italian bike, in which case the fixed cup tends to fall out.)
Bit of trivia: It was the Wright brothers who figured this out and adopted the LH pedal thread in the left pedal.

Absent the power, a generally sure-fire way to get that cup out is to hold the tool in place with a bolt and use a vise.

One of the YouTube videos (I watched a few while fighting with the frozen-in cartridge) showed the Sheldon Brown method for removing a seized bracket on the drive side (old school bracket, for accommodating loose bearings or a bearing race). It involved running a bolt through in place of the axle, clamping the bolt to the bracket, and then turning the bolt out. Clever! Not applicable to my situation, but I always enjoy learning new stuff.
 
Originally Posted By: CR94
I can assure you from personal experience, as well as theory, that when (fortunately rarely) the RH thread of the right side of my Italian-threaded BB began to loosen, it unscrewed itself remarkably rapidly. That happened in the middle of a ride and I tried to make do by finger-tightening the loose cup. I couldn't pedal more than maybe half a mile each time before the right BB cup became extremely loose again.

Visualize the outer surface of a cylinder rolling without slipping against the inner surface of a slightly larger cylinder that's fixed in place. Each time the center of the inner cylinder completes one revolution, its outer surface rotates slightly in the opposite direction. Right? Essentially, that's why the BB cups tend to rotate slowly in the opposite direction from crank rotation. That can be a problem if the rotation is in the direction that loosens the threads. Therefore, "British" threaded BBs sensibly use LH threads on the right side.

Thanks, good explanation, makes sense now. This also explains why bike tubes 'walk' within the tire, resulting in the valve stem being at an angle, correct? (And why, in the '60s, Chryslers had LH-thread lug nuts on the driver's side wheels.)

Obligatory automotive note: I see that you had a 2nd-gen Mazda GLC that you got incredible mileage out of. My wife bought one new in late '82 - the only new car either of us has had. It was an outstanding car - written off in '96 unfortunately, after being rear-ended.

Ours was a blue 2-dr hatch, with the 1.5 l engine and a 5-speed manual. Very good on gas, and a very reliable car.
 
Originally Posted By: Number_35
Thanks, good explanation, makes sense now. ... (And why, in the '60s, Chryslers had LH-thread lug nuts on the driver's side wheels.)

Obligatory automotive note: I see that you had a 2nd-gen Mazda GLC that you got incredible mileage out of. My wife bought one new in late '82 - the only new car either of us has had. It was an outstanding car - written off in '96 unfortunately, after being rear-ended.

Ours was a blue 2-dr hatch, with the 1.5 l engine and a 5-speed manual. Very good on gas, and a very reliable car.
Yes, thanks! I'm still skeptical whether Chrysler really needed their left-handed lug threads, considering that adequately tightened RH ones generally don't loosen on other cars.

Correct about the GLCs. Mine was almost identical to yours, except its color ("Calm Beige") and clock (the only visible change for '82). The engine never showed any clear sign of wear, although it had a few other problems.
 
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Can't say my Italian threaded bottom bracket has loosened at all, but she's only got about 100k on her. I don't see an issue if it is adequately tight and well adjusted, but it is possible.
The lug nuts wouldn't matter, they don't see a torque in use.
 
From my experience, a steel BB cup or body into an aluminum frame shell is asking for trouble and I buck the practice of using grease or Shimano's dry-applied threadlocker for a coat of Loctite C5-A. Never had a problem removing my Shimano Hollowtech II bottom bracket shells since I did that.

Shimano did try to mitigate this with plastic or Al/Ti non-drive side thread adapters, only to fail. It's worse with BB30/PF30/BB386/BBRight - carbon fiber bikes don't have precise tolerances and driving a steel bearing into an aluminum frame is asking for trouble.
 
I like using a park socket with a bolt into the spindle holding the socket in place. Then you just take a large wrench to the flats on the socket and work it loose.
 
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