External Bottom Brackets

RollYerOwn

Ok this might be a stupid question but I can't figure it out.

I am building up a hardtail mtb from parts from my old bike, a new frame and needing some newer parts.

I bought a Deore crankset several years ago on ebay and never fitted it, so I'm planning to fit that (seems to be one of the two octalink versions). My old bike had square-tapered spindle in a sealed cartridge.

I have been looking at the new-fangled external bottom brackets and was looking to pair this with a new spindle, but I can't find one on line. Anywhere. Not one bike shop seems to sell them. I can find plenty of octalink sealed cartridge bottom brackets...

I don't get it. What am I not understanding?

RollYerOwn

Just to be clear it's the spindle I can't find, not the external bottom bracket itself...

langdang

Doubt octa link will work with the external "Hollowtech"BB. The Hollowtech cranks come with an integrated spindle/axle EDIT- see below
[scouser]Octalink is crap anyway[/scouser] - got burned by that years ago and it nearly turned me off shimano altogether with their constant f***-acting with compatibilities.
A Deore Octalink can't be standing you too much, you can use as a paperweight/tribute to Shimano aresology like my almost perfect LX Octalink

ednwireland

if its octalink its not external bearing

octalink bottom brackets and chainsets arent interchangeable with the newer external bottom bracket.

external cups (the spindle is fixed to the chainring side)

http://www.chainreactioncycles.com/Models.aspx?ModelID=34674


octalink bb

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

RollYerOwn

*sigh*

Thanks guys. I was beginning to suspect something like that.

RollYerOwn

So that would mean if the spindle splines went you would have to replace the entire crankset...?

Nice.

langdang

Get an octalink BB by all means (if you can find the right one), but the Hollowtech external setup is WAY better as long as your BB shell and faces are straight. May need the BB "faced" other wise. I didn't face my old MTB BB and the external bearings are still going strong (and I'm not exactly a bantamweight)

ednwireland

RollYerOwn wrote: »

So that would mean if the spindle splines went you would have to replace the entire crankset...?

Nice.

Yup

mangled enough square tapers over the years - theres several in my shed

blorg

RollYerOwn wrote: »

So that would mean if the spindle splines went you would have to replace the entire crankset...?

Nice.

It's unlikely to happen though with a Shimano external bearing crankset. They fit together with only loose hand pressure and then are secured with two clamping bolts. If you stripped the threads on those bolts (which you really shouldn't) you can just replace the left, non-drive side crankarm.

RollYerOwn

Well as trying an external bottom bracket would mean also splashing out on a full crankset at this stage, I think I'll give it a miss. There's a recession on! Maybe in a couple of years when the new sealed octalink bearing goes.

Not much point these days in buying something to last more than a couple of years before Shimano bring out the new latest technology that requires a new set up and a new set of tools to maintain it.

I'm still not convinced that threadless headsets were necessary as I like to be able to adjust my riding position.

Anyway. Thanks for the responses!

gman2k

RollYerOwn wrote: »

Well as trying an external bottom bracket would mean also splashing out on a full crankset at this stage, I think I'll give it a miss. There's a recession on! Maybe in a couple of years when the new sealed octalink bearing goes.

Not much point these days in buying something to last more than a couple of years before Shimano bring out the new latest technology that requires a new set up and a new set of tools to maintain it.

I'm still not convinced that threadless headsets were necessary as I like to be able to adjust my riding position.

Anyway. Thanks for the responses!

Yep, if you have the new octalink chainset, then just get the matching octalink BB, you'll notice no difference once you're rolling (YerOwn).
BTW, there is a MTB specific octalink BB, it has deeper splines if I remember correctly. You can't use the road octalink.
Chainsets and BBs are probably the easiest thing on a bike to fit yourself once you have the tools. Make sure you get loads of antisieze grease in there while you're at it.

zil

blorg wrote: »

It's unlikely to happen though with a Shimano external bearing crankset. They fit together with only loose hand pressure and then are secured with two clamping bolts. If you stripped the threads on those bolts (which you really shouldn't) you can just replace the left, non-drive side crankarm.

It shouldn't but it can . My non drive crank has a habit of falling off due to lightly stripped splines on the spindle. It's only happened twice and last time I put things back together I scoured out the splines and poured half a bottle of locktite on the clamp bolts, it's lasted a few months since then so hopefully I won't need to buy a new crankset however it seems like slightly naive design that a few little 2mm splines on a spindle can ruin a €400 crankset