External Bottom Brackets

The plastic spacing bush that sits between inner bearing surface & crank axle are often made of shit grade plastic. What happens over time is the oil/ grease/ anti-seize that you have pasted your axle in, have infact, been swallowed up by the plastic bush and swell onto the axle.

Older suspension forks used to do the same thing, the very oil thats meant to lubricate & damp them, actually made all the plastic components swell up and seize, jokes eh!

Get a shimano XT or ultegra grade EXT BB or try and find one of the higher end RaceFace or Hope ceramic or stainless bearing BB's. They will last a proper amount of time, though you pay for that, just like anything. Some EXT BB's don't have the plastic spacer, just axle > bearing surface, but obviously, in England, not a great idea.

Also can't stress enough how important facing the BB shell is. Essentially if you don't get it done*, expect trouble, nothing less.
*and done by someone who knows what they are doing

That about sums it up.

I've run a Hope SS BB and Race Face Cadence cranks for over 12 months and 4000 miles. Still smooth and silky like new.

the tolerance shim bb's and cranks are made to is tight

first face chase the bb

degrease the threads

antiseize all threads

install bb with correct spacing and to the right torque ~40nm drive side tightend first

clean of exess antiseize

film of grease all over crank axle

push crank through bb should go through by hand ... no hammering, even by hand!

retract crank slightly and wipe of lip of grease between bb seal and spider ... stops crap biulding up

push crank back in

install non drive side checking that saftey tap is in position

tighten plastic or ali end cap into axel by hand.

back it off

use torque wrench to tighten it to 2.5-3nm usualy off the scale of most home torque wrenches. might also need an icetools tool which uses a 8mm allen key to drive it.

tighten the pinch bolts evenly to 12-14nm

evenly means tigthtening progressivly there is no need to half a turn on each

wipe of an mis grease / antiseize

check pinch bolts and gunk biuld up every 2 weeks - month
dependant on how much riding / dirt you get up to.

my sram cranks:

bit of grease on threads

screw the cups in by hand

tighten the cups with the tool as much as you can by hand

put on the cranks

external bb rocks

so simple to install, have them on all my bikes now

Can I change the thread title now? External BBs are great, I have sex with them, fuck yeah!

external bb's are better than 531 unless you are a luddite

I'm a luddite.

Even a 2008 frame may not have been faced if it wasn't sold with an external BB from new.

I fitted an Ultegra BB to my cross bike and it stills runs like new after a years use in all weathers and conditions (it is my only bike and used for everything), hosed down each weekend etc,.

I don't however remove the chain set and it never creaks. What threads start creaking on an external BB chainset?

The two pinch bolts in the non drive crank.

I'm going to get my bbshell faced and buy some anti sieze. Just been using grease.

though I would add, mechanic in blue door bikes in Crystal palace said he wasnt surprised my tiagra bb cups fell apart after 3000 miles, much of it wet and or offroad.

It's all about Raleigh threading and cotter pins.

I don't see peoples trouble with cotter cranks? I rode a set of middle of the road stronglights that were about 30/40years old with the right size pins in them. Did about 750miles in a month on them and they never gave any bother. Flexible as fuck compared to modern external BB cranks, but then thats like comparing a Lotus Exige with a 3wheel Morgan in a torsional stiffness test.

anyone care to suggest a good quality externall BB that will give me years ot trouble free cycling ?

Shimano Ultegra ? DA ? Hope Creamic ?

Just buy one that fits and replace it when it needs it.

If someone says "my Hope Ceramic has lasted 4 years and over 20000 miles and is still going strong" does not mean you'll get the same.

1. Is your frame faced?
   
2. Are you light in the loafers?
   3, Do you mash the pedals?
   
3. Do you climb seated or are you always out of the saddle?
   
4. Do you keep your drive train clean?
   
5. Do you use a jetwash ever?
   
   

These will all have an effect on the longevity of a BB

Chris King do a Hollotech ii implementation. I'd imagine that should you install it correctly it would treat you right.

Having said that external Hollotech BBs are pretty simple to replace and as I understand it replacing them has no affect on the longetivity of your cranks - unlike square taper. I reckon the Hollotech philosophy is that you replace the BB when you strip and clean your crankset every 3000 miles or so.

You could also try replacing the bearings in your cups with some high quality ones and see if that gives you the result you want.

ah now thats an idea
i guess you could pop out the black ring here and see what lie behind ? sks roller bearings ?

Standard cartridge bearings. You can push the black dust cap off to get access to the bearing. You can then raise the seal on the bearing with a scalpel and re-grease it if you need to. Or you can pop the bearing out and replace, but to do it properly you'd need some kind of bearing press - I think a headset press will do.

Oh, and that pic is a GXP BB which - as I understand it - isn't compatible with hollotech ii. Just in case you have a truvative or SRAM crankset and were thinking of replacing the BB with Shimano / Chris King / Mega Exo etc.

A lot of lbs now have a ht2 bearing press as they are also fed up of constant cup changes. i think they can do it with cups still in the frame.

My next bb will be a hope ceramic, havent heard as many good things about anything else

Yep, annoyingly found out recently that shimano, fsa and sram all have different external bb's

so is that right, you can just replace the bearing cartridges instead of the whole cup?

A lot of lbs now have a ht2 bearing press as they are also fed up of constant cup changes. i think they can do it with cups still in the frame.

My next bb will be a hope ceramic, havent heard as many good things about anything else

We don't and I'd rather just change the whole bb. Wasteful maybe but they ain't expensive and it's usually a 5 minute job if that. I imagine pressing bearings in and out would be a bit more labour intensive and surely the cups will have a limited lifespan if your removing/replacing the bearings which are an interference fit?

Unless you've got a CK or other exotic and expensive BB it's probably better to replace the cups.

But if you want to experiment with high quality off the shelf bearings buy a basic external BB then pop the bearings out - it's surprisingly easy - then put the new ones in with a suitable press. Just be careful not to crack the black dust seals - they are pretty brittle.

Compatibility: IIRC some basic FSA Mega Exo chainsets will work with Hollotech ii BBs, but SLK-Light / Force do not. <-- read this on the internet somewhere when trying to figure out what BBs would work with an old FSA Team Issue crankset, so you probably would need to confirm it before committing.

Truvative / SRAM have their own system that requires a specific BB.

We don't and I'd rather just change the whole bb. Wasteful maybe but they ain't expensive and it's usually a 5 minute job if that. I imagine pressing bearings in and out would be a bit more labour intensive and surely the cups will have a limited lifespan if your removing/replacing the bearings which are an interference fit?

This is pretty much my view too. Once the bearings have died, chances are there is going to be some distortion to the cup, or the bearing may well have seized and slipped around in the cup, making it oversize, so pressing fresh bearings in is just a waste of time /effort.

But, some of the MTB guys swear by this method, they just pick up a shimano XT BB, and a dozen bearings, then just keep on top of them.

Remember ISIS and how often those used to go ? I've got a raceface signiture Ti ISIS BB from about 1999/2000, which cost a small fortune (£180? back then!) but its still going strong, has an obscene milage on it and has been on a SS MTB/commuter for last 7years now.
Its a 4x bearing job, and when/if anything goes wrong with it, you send it back to RF with receipt and they give you a new one/ press fresh bearings in/ whip the tech who made it.

Pretty much you get what you pay for!

This is pretty much my view too. Once the bearings have died, chances are there is going to be some distortion to the cup, or the bearing may well have seized and slipped around in the cup, making it oversize, so pressing fresh bearings in is just a waste of time /effort.

Which is why, IMO, Trek are wankers for putting BB30s or whatever those stupid arsed press fit things are called, on their mtbs. We have had so many of them go wrong.

Installing an external bottom bracket for the first time (campaign centaur) on a steel, Italian threaded frame. Instructions recommend the bb has a water training hole. Is this critical?

Also, when it recommends facing the bb shell what does this mean? It obviously has threads for the installation of the original bb.

First full build so any help appreciated.

^ read the thread from top to bottom.

One way or another, water gets into bike frames and flows down hill to the bottom bracket. A drain hole lets it out. Without one, you can accumulate rust slurry which will kill your bearings when it tries to seep out through them.