Another bottom bracket removal problem

[Bman]

Went into the LBS today and asked about my crankshaft as it has lots of movement or "wobble"? I have previously done all repairs and maintenance on my bikes myself. But Im not a mechanic and have never messed around with cranks or shafts before. So I'm a little out of my depth but would still like to do it myself. I'm only just getting to grips with the terminology!

After looking at the bike and weighing up options, he sold me the crank arm removal tool and some new bearings. The tool will be useful in future even if the bearings dont fix the problem. The bearings were very cheap anyway.

Managed to get the cranks off fine, just as he explained. however trying to get into the crank shaft itself in order to change the bearings seems impossible.

The setup is almost identical to this diagram (I hope parktool.com wont mind me hotlinking ) :

I have no idea what is between the cups and within the "shell" but I can only assume it is very similar to this diagram.

Ive managed to remove the Lockring, but neither of the cups want to move at all and I dont want to damage the part where the tool grips the cup. I can see the thread on the cup so know which way to turn, but my spanners dont grip enough of the metal to get it to turn.

Is there a better tool (other than an ordinary spanner) that Im supposed to use to remove the cups?

 

[tyred]

Are your cups the type which take an ordinary open ended spanner (11/16" I think or is that only on Raleighs?) or does it have a serious of pin holes for a pin spanner? Unless you are replacing the cups, you shouldn't need to remove the fixed cup. The diagram is pretty accurate as to what you'd find inside. The bearings may or may not be in a retaining ring.

If you're using an ordinary open end spanner, can you use the crank in some way to clamp it in place so it doesn't slip off?

 

[top-tube]

Fixed cup should have 2 flat sides. IME, use an adjustable wrench around the flat sides, and a quick firm bang on the wrench handle with a hammer should see it loose.

Adjusting cup - should be a raised section in middle of cup allowing a thin spanner to get some purchase. I've normally managed it with adjustable wrench - again hammer required to work the cup loose. If all else fails, screwdriver/chisel against the raised section assisted by hammer on end of screwdriver to knock it loose.

Makes sense to add some anti seize grease when putting it all back together.

 

[TheDoctor]

Or get the LBS to remove it and replace with a sealed BB. That's what I'd do.

 

[Bman]

Its difficult to explain. its almost like I need a spanner with longer "fingers?" to grip the cup properly. Or possibly two of the same size?

I didnt want to have to draw a picture, but I've had to. (should have taken a pic when the cranks were removed).

The attached pic is of the two cups, the right is the drive side.

I was having the biggest problem with the left cup, the spanner only just grips the top half of the rectangular part, that and it only protrudes a few Millimeters. If I could find my other spanner, I could give it more force.

I also tried the hammer and screwdriver trick to try and loosen it. After I failed I assumed there must be a specific tool to remove them.

Im using just an adjustable spanner, because I cannot find my standard ones

The Doctor, If I can repair this, I shouldnt ever need to do it again. The bike has seen many miles and is nearing the end of its life

 

[tyred]

You only need to remove one (preferably the adjustable one) if you are only replacing the bearings. Spray with WD-40 and leave overnight. A good fitting adjustable spanner with minimal play in the jaws is probably best. Hit it a hard crack with a hammer to unscrew as the shock may loosen it. You could try some heat, not too much. Just remember that the left hand side has a left hand thread.

 

[PpPete]

I got a headset spanner 30/32 & 36/40 that will fit most trad BB cups. Works a lot better than adjustables. Actually I prefer it to those horrid spline jobs on cartridge BBs.

I did have one recalcitrant BB though - maybe like your left pic. LBS had a special ring spanner with an elongated sort of lozenge shaped hole that had it off in seconds. Didn't charge me either !

 

[Bman]

That sounds like what I need. I might have to pop back down the LBS again when I can be bothered (or when it stops raining!). I want to fix it myself to save money and learn something new. I'll see if I can just get them to loosen it for me. They seem helpful enough.

Of course I will say that I loosened it for him!

 

[Landslide]

In the past I've had success in removing the LHS (adjustable) cup with either gas pliers or a pair of mole grips.

 

[Ivan Ardon]

I use two spanners on the L/H adjustable side, one on each end of the flat bit with the axle on the middle.

 

[TheDoctor]

I'm sure there's a bodge for this, involving big bolts that go through the cup, and nuts to grip with a spanner...

 

[Bman]

[snip]
If you're using an ordinary open end spanner, can you use the crank in some way to clamp it in place so it doesn't slip off?

Just tried this, no luck. The spanner didnt slip as much, but the cup still wont move.

Its soaking in WD-40 at the moment

 

[andrew_s]

I'm sure there's a bodge for this, involving big bolts that go through the cup, and nuts to grip with a spanner...

That's for getting the fixed cup out after the adjustable cup and axle have been removed. The fixed cup is generally the hard one to get out as it would normally be left in place until a new BB is needed, whilst the adjustable cup should be removed at regular intervals for servicing and regreasing the BB bearings.

 

[02GF74]

Just remember that the left hand side has a left hand thread.

nope. we refer to sides from thje riders perspective when riding in the correct position.

the right hand side - where the chain rings are or the fixed cup - is left hand thread.

the other side or adjusable cup woitrh lock ring is right hand i,.e, normal thread.

so attach the left hand cup and undo it as you would a normal bolt.

not if you have stell frame and the cup has been in there for a long time, it can be a right bugger to undo.

use plus gas or proper pentrating fluid instead of wd40.

try to undo as well as tightne it to break the bond. you may need proper spanner and a length of pole to shirt it - you will need to apply a lot of force so be careful the spanner does not fly off and smack you.

 

[Bman]

Ive had no luck with this lads....

Days of soaking in WD-40, two adjustable spanners, brute force, mallets, heat. Ive even tried tightening it to break the seal. I'll have to take it down the LBS and challenge them to remove it