Bottom bracket question.

The tax man

Hey folks, I'm giving my bike an overhaul atm and took the BB out last night.
It's one of these and all my previous BB dealings were with the cup and cone type.
My question is how these should feel i.e how freely should the spindle turn by hand? Mine feels as if it's full of treacle and not grease, so turning the spindle by hand feels stiff. No gritty or dry noises at all.Spindle turns smoothly,just not freely enough as I thought it should. BB is about 4 yrs old now but hasn't done much mileage until I started back on the bike this year. I'm talking roughly 2,000kms max on dry roads.

So is this resistance I'm feeling normal or has the lubrication contents of my BB gone off over time through lack of use?

Thomas_S_Hunterson

Stick a pair of cranks on it and see how it feels. It probably just feels stiff because you are just turing the axle with no leverage.

biker_joe

While you have it stripped, you may aswell replace it, I have seen 105 BB on probikekit for around 30 Euros ...... it's one of those parts thats always moving so better safe than sorry .... if you feel anything while turning it by hand the bearings might be shot.... so yea it does sound a bit F**ked ....and it's a sealed unit ... so defo get a new one !!!

Biker Joe...

The tax man

Sean_K wrote: »

Stick a pair of cranks on it and see how it feels. It probably just feels stiff because you are just turing the axle with no leverage.

When I took the chain off for a clean and started turning the axle by the cranks is when I noticed it first, even with the extra leverage.

For €27 from CSS I think I'll just replace it.

Cheers guys.;)

zzzzzzzz

http://www.chainreactioncycles.com/Models.aspx?ModelID=906

http://www.chainreactioncycles.com/Models.aspx?ModelID=11726

Excuse my ignorance here, but is the first link there a cartridge style BB and the second link a "cup and cone"?

Also - how can I tell what BB I need (do I have to remove it to check or is it easier than that?)

Húrin

biker_joe wrote: »

While you have it stripped, you may aswell replace it, I have seen 105 BB on probikekit for around 30 Euros ...... it's one of those parts thats always moving so better safe than sorry .... if you feel anything while turning it by hand the bearings might be shot.... so yea it does sound a bit F**ked ....and it's a sealed unit ... so defo get a new one !!!

Biker Joe...

If the ball bearings are 'shot' he only needs to replace them, not the entire BB.

blorg

aidan.offbeat wrote:

Also - how can I tell what BB I need (do I have to remove it to check or is it easier than that?)

Generally will be determined by your cranks, on most modern racers they will have a crank-integrated-spindle external cup system, probably Shimano, Campy or Truvativ/SRAM. The cups are pretty cheap, in the £25 bracket.

Slightly older bikes may need Octalink or ISIS, older still, SS/track/fixed or entry level may be square taper.

The tax man

Húrin wrote: »

If the ball bearings are 'shot' he only needs to replace them, not the entire BB.

Can a sealed cartridge be taken apart easily?

The tax man

aidan.offbeat wrote: »

Excuse my ignorance here, but is the first link there a cartridge style BB and the second link a "cup and cone"?

Also - how can I tell what BB I need (do I have to remove it to check or is it easier than that?)

Top one is a cartridge BB,bottom one is the old style cup and cone type BB.(re: pic)
I didn't know I had a cartridge BB till I took it out. I thought a cartridge BB only referred to the BB in your second link,the ones with outboard bearing cups.
I seriously need to catch up on bike technology.:D

Handy link

zzzzzzzz

The tax man wrote: »

Top one is a cartridge BB,bottom one is the old style cup and cone type BB.(re: pic)
I didn't know I had a cartridge BB till I took it out. I thought a cartridge BB only referred to the BB in your second link,the ones with outboard bearing cups.
I seriously need to catch up on bike technology.:D

Handy link

Deadly - that link makes everything very clear.

I was looking at the octalink wondering how the hell my cranks would attach... have one the same as the top one in your pic.

DirkVoodoo

The tax man wrote: »

Can a sealed cartridge be taken apart easily?

Not that I know of. Sealed units have to be replaced once they wear out.

The tax man

DirkVoodoo wrote: »

Not that I know of. Sealed units have to be replaced once they wear out.

That's what I thought.

biker_joe

Húrin wrote: »

If the ball bearings are 'shot' he only needs to replace them, not the entire BB.

can you read ! it's a sealed unit, and sealed unit are not serviceable and can only be taken apart by sledge hammer !!!

God you try and give a bit of advice .....

rant rant rant

biker joe

doozerie

The tax man wrote: »

My question is how these should feel i.e how freely should the spindle turn by hand? Mine feels as if it's full of treacle and not grease, so turning the spindle by hand feels stiff. No gritty or dry noises at all.Spindle turns smoothly,just not freely enough as I thought it should.

If it turns smoothly then it is probably fine. They do feel a bit "mucky" when you turn them, even when brand new, it's because they use relatively thick grease. A lot of force is exerted on the bottom bracket when pedaling, and if a lighter/thinner grease were used then chances are your bottom bracket would last no time at all before the bearings were worn out.

The same is true for the axles in your hubs and pedals (which usually use a lighter grease) - if you turn the axle itself it typically won't spin, but if you turn the "outer" object (either the wheel or the pedal) then the extra weight allows it to spin round the axle.

doozerie

blorg wrote: »

Slightly older bikes may need Octalink or ISIS, older still, SS/track/fixed or entry level may be square taper.

Age is the determining factor far more than whether something is entry level. Before ISIS and the like came long, pretty much everything used square taper, from the most basic stuff right up to Campag Record and Dura-Ace. I wouldn't buy a square taper crankset if I were buying now, but my square-tapered 10-year old Campag Chorus crankset is still a very good piece of kit even today.