Bottom bracket size and spindle length

ricktabor1

Hi everyone,

I've just bought a 2007 Kona Caldera frame to replace my 2008 Cindercone (i'm a very old fashined kind of guy!).

The bottom bracket in the Cindercone was 73mm (FSA powerdrive). The Caldera requires a 68mm BB. I want to switch my Chainset over.

If i buy a similar BB to the original one but 68mm, will i still need the same spindle length?

I hope i've supplied enough info.

I notice that most bottom brackets have three spindle lengths - is this for singlespeed, double or triple chainsets, or is it more complicated than that?

Any help would be greatly appreciated.

Thanks Rick

nicklouse

bin it all and get new.

but yes same axle length for your cranks.

supersonic

Yes, should be same axle length. Most chainsets tech info supplies the needed lengths for certain chainlines. So unless this new frame requires something different, is the same length axle.

ricktabor1

Thanks for the fast replies.

Nick, why do you think i should get rid. Is the Power drive system a bad one?

nicklouse

cheap and nasty. not really and engineered solution.

but it works and is cheap to replace bits.

ricktabor1

Do you think square taper is better?

I would get Hollowtech II but i don't really want to spend too much.

supersonic

The axle type must match the crank.

Square taper is very reliable, but heavy and can flex.

ricktabor1

Sorry, yes i know that the axle must match the crank but i was just wondering what would be the best option for the least amount of cash.

I guess that just replacing the bottom bracket will be cheapest but if i got another option that wasn't too expensive, i'd go for that.

supersonic

WHat is your budget? 7, 8, 9 speed?

ricktabor1

It's 9 speed. I'd settle for Truvative isoflow or, deore standard chainset,

supersonic

The Deore Hollowtech 2 is great value, but you will need to face the frame.

Alivio Octalink is also good, and uses an octalink cartridge BB:

http://www.jejamescycles.co.uk/shimano- ... 65396.html

ricktabor1

Thanks supersonic. Much appreciated.

I take it that Octalink is considered better than Powerdrive then.

Irealise that i'm asking a lot of questions but........ are powerdrive and ISIS different systems?

dan1502

I have a Raceface Evolve XC chainset taken off my 2008 Kona Kula Deluxe 29er. I bought it as new less than a year ago so it's basically had less than a year's use. The chainrings are all fine and I have a brand new spare outer ring too. However the bottom bracket though running freely felt a bit 'gritty'. I removed it and found that an inner plastic bit had cracked off a bit. I regreased it all so it may be ok so though I would throw it in you might need to replace it but could probably use it for a while.

I have just taken my frame in to be faced as although it had an external BB fitted from new, Kona don't face the frames and it had paint on. I wondered if this might be why the BB failed so soon. The LBS reckon without facing the frame the Shimanos BBs only last a few months too.

nicklouse

PS and ISIS are different (there is also another FSA version) and the 2 Octalink standards.

Octalink used to come on the top of the range shimano stuff. XTR and down.
Powerspline is entrylevel and OE stuff.

supersonic

Yes, powerdrive, powerspline, octalink, ISIS and square taper all have different interface, but use a screw in cartridge system.

Not sure of the axle length you need with that Alivio chainset - but should say on Shimano's website in the tech docs.

ricktabor1

Thanks for all that info everyone.

Sorry about my late reply..... I fell asleep with my laptop on my knee!. Serves me right for hitting the ale on a school night!

Thanks for the offer of the chainset Dan. How much are you looking for for the set and BB?

dan1502

Sent you a pm a couple of days ago. Let me know if you're interested before I advertise them.