Bottom bracket help!

i have a question that is related to choosing a bottom bracket, as i think i have chosen the wrong one, but i can't figure out if it's the crank or the bottom bracket that's wrong. this is my problem:

is this ok/normal? it doesn't look right to me...
what can be done to remedy this?

That looks a LONG way outboard to me. Here's a collection of common mistakes when doing a 1st build, all of which are easily doable, but after you have done them once, hopefully you won't make the same mistakes again:

• BB spindles come in different lengths (from close to 100mm to over 120mm)
  
• BB spindles come in different tapers (ISO and JIS)
  
• BB cups come in a variety of different sizes and thread directions (English, French, Italian...)
  
• Cranks almost always specify the length they need for correct chainline (particularly crucial if you are running fixed/ss). It is highly unlikely that just whopping any old BB and cranks together is going to be acceptable.
  
  

I'd suggest that you swot up here:

http://sheldonbrown.com/bbsize.html

http://sheldonbrown.com/chainline.html

Sam

mine's like that except not that far from the shell. I just keep tightening the bolt until it literally can't go anymore lol

Probably not the best way but I'm not too fussed about the beater whereas yours is probably your main bike?

I'm not an expert on this but I think you have the wrong type of bottom bracket for the crank you are using. If you let people know what crank it is and what bb then I am sure someone will know. As far as I am aware, there are two types of square tapers, one is jis but not sure about the other.

Too late, read above :-)

You will get a little bit of adjustability by tightening more or less, but this is not advisable as you can damage your components. You don't want to tighten so much that you initiate fatigue cracks or stretch out the taper in the crank. Usual torque figures are somewhere in the 32-39nm range.

On the question of removing a chainring, you can, but will need to space with these otherwise the bolts will not tighten properly:

http://www.jejamescycles.co.uk/id-outer-chainring-item153898.html

You can usually mount the remaining ring on the side of the spider which gives the better chainline if you're doing a beater job, though putting it inboard may not be aesthetically pleasing.

thanks for your reply. i was not aware that there were different tapers on the bb spindle. (yes, as you can tell, it's my first build!)

the bb is a shimano one i picked up on
ebay and the crank is a sturmey archer fct 46:

Shops selling the crank say that it needs a spindle length of 110mm, (which is what my bb is) and needs a 'square taper', does this mean JIS or ISO?

Sheldon Brown says:

If you install an ISO crank on a J.I.S. spindle, it will sit about 4.5 mm farther out than it would on an ISO spindle of the same length.

which halve the distance i'm getting, so i have feeling my crank needs a ISO spindle, but this doesn't feel right as the recommended bb by sturmey archer is a JIS!

Apologies for the mass confusion and bad writing, any suggestions/pointers would be greatly appreciated.

Both JIS and ISO are square taper, they just have differing dimensions which is why a set pair of cranks will sit different distances out on each. It sounds like your cranks and BB are both JIS, which would mean that likely culprits are:

• You haven't torqued the crank bolts to the right value.
  
• The BB is installed the wrong way around
  
• The spindle size is the wrong length.
  
  

Have you done a sanity check to make sure the spindle is the length that you meant to order?

Hey guys

First of all i have a problem similar to Alemera. I've removed my buttom bracket from my frame.
At the spindle of the buttom bracket it's shown that's a 3P buttom bracket model.

http://sheldonbrown.com/bbsize.html

My question is what buttom bracket i should get for my frame?

• The rear chainline meassurement is 110 mm.
  
• My crankset is http://www.chainreactioncycles.com/Models.aspx?ModelID=54762
  
  

Regards balle

Hi,
I am trying to overhaul my bottom bracket, I am really new to this, all I know about the BB is "CH chromoly axle", and I am not sure which tools should I get, will any hook tool do? and especially the pin spanner, I can't find info to make sure which one will fit this particular bb.
Also what can you tell whether it is a cone/cup or some kind of cartridge?, I.E should I get just some caged bearings and grease?

Apologies for the basicness , I have searched the forum but since this question is specific to this bracket I couldn't find my answer.
Many thanks in advance

1 Attachment

you need to take the cranks of first...

Damn I thought an allen would do for the crank, now i see I need another tool for that.. I'm happy to learn to do this for the first time I just don't want to buy the wrong tools..

Yeah you need a crank puller, worth buying one as you'll probably need one at some point again and theyre not that expensive

cool cheers, they're standard then no chance to go wrong? and for the bb tools any way of telling which hook/pin spanner without taking out the cranks?

Read Sheldon Brown's website first.

Be careful that the "CH" isn't short for Swiss. It probably isn't.

You want a c-spanner which is built into the side of any shitty pressed-steel multi tool like you get in a Poundland puncture repair kit. Or use a large blade screwdriver.

You don't generally need a pin spanner to adjust the adjustable cup; just use your hand to adjust it assuming it hasn't seized. Or a pair of needle-nosed pliers which you don't care about.

Strip, and bung in a load of your favourite grease. If the bearings look scuffed, then replace.

Don't bother removing the drive side cup unless you want to swap out the whole unit.

@ono: that's a cup and cone, for sure. With the right tools, you do NOT need to remove the crank in order to adjust the bottom bracket. You'll need a standard BB lock ring spanner (eg Park HCW-5) and a pin spanner (eg Park SPA-1).

Sheldon explains how to do things here: http://sheldonbrown.com/tooltips/bbadj.html. Just remember to loosen the lock ring before trying to use the pin spanner on the cups.

And if you want to service the "fixed" cup on the other side, you can do it without removing it (which can be really hard and uses a special spanner) by a) taking off the drive side crank and then b) loosening the non-drive side cup completely c) pulling the axle through so it comes out the non-drive side. Put an old t-shirt down to catch the ball bearings otherwise you'll be searching for them for the next couple of decades.

Thanks rodabod and benbrangwin, I'll get those in amazon and give it a good go.

I've worn out my second GXP BB and I can't be bothered replacing it every six months, even though they're cheap as chips. I know Hope + spacers is an alternative but are there any others?! Could I run a Shimano Hollowtech with the Hope spacers?

Possibly, but the GXP system relies on the NDS bearing & cup to resist forces pushing the axle left and all other systems give that job to the DS bearing so it would be a bit dodgy.

Early failure might be a sign of poor alignment - did you get the frame faced when they were first installed?

Hello All!

I need to swap out an octalink bb to a regular square taper (probably gonna be a campag)

It's an italian threaded Pinarello treviso if that helps, but I as you can imagine what to make sure I get the right bb!