Bottom Brackets

[francovendee]

I grew up at time when adjustable BB's were the norm and found they were OK.
Along came sealed BB's and I found these extremely long lasting and maintenance free, a huge improvement.
Looking at a bike on offer it comes with an Octalink BB.
I have no experience of these and wonder what are the pluses and minuses over the square taper I'm familiar with.
I guess a whole new load of tools would be needed to change one?

[simonineaston]

I agree - it's a freekin' bottom-bracket nightmare out there - and as has been commented here recently, a lot of them have the timerity to call themselves 'standards'! This isn't bad at all (use Ctrl + F and search for "octa")

[the snail]

I think the -ve with octalink is that the larger spindle means that there is less space for the bearings vs. ST, which is why they went to external bearings with HT2. I don't know what the choice of parts is, but I think octalink is a bit of a dead-end design, with ST still persisting, at least with some manufacturers.

[Brucey]

I grew up at time when adjustable BB's were the norm and found they were OK.
Along came sealed BB's and I found these extremely long lasting and maintenance free, a huge improvement.
Looking at a bike on offer it comes with an Octalink BB.
I have no experience of these and wonder what are the pluses and minuses over the square taper I'm familiar with.
I guess a whole new load of tools would be needed to change one?

You need TL-UN74 (or similar) which also fits BB-UN** ST bottom brackets.
You also need an Octalink compatible crank extractor. This is identical to a ST one, except that the 'pusher' has an adaptor on it which is larger diameter, so that it can push on the larger diameter octalink BB spindle. Most crank extractors are now made to do either ST or Octalink.

Octalink BBs usually don't last as well as ST ones . The better quality octalink BBs are now no longer made. When buying an octalink BB you need to worry about the usual things (BB shell width, threading and spindle length) but also whether the octalink is V1 or V2, which are not compatible with one another; the spline lengths are different.

Octalink cranks normally work OK but occasionally one will work itself loose in such a way that you don't notice when riding and this wrecks the crank; they only 'fit properly' if the mating diameters are a light interference fit. If the fit goes, it is invariably the crank that is bad, IME.

It is possible that shimano will abandon the octalink design entirely (it is still 'current' in some models, in V2 form) and that there won't be any more bottom brackets to buy; octalink V1 BBs are now 'hard to find' in some lengths. I think that octalink will go extinct at some point and when it does you will still be able to buy ST stuff.

cheers

[keyboardmonkey]

... Looking at a bike on offer it comes with an Octalink BB... I guess a whole new load of tools would be needed to change one?

If you currently have a crank extractor it may be compatible with both ST and Octalink BBs.

For whatever reason I ended up getting a fiddly little ‘plug’ to use with my ST extractor: TL-FC15. Something to consider...

BB tools

They cost a fiver now

TL-FC15

[printedland]

If you currently have a crank extractor it may be compatible with both ST and Octalink BBs.

For whatever reason I ended up getting a fiddly little ‘plug’ to use with my ST extractor: TL-FC15. Something to consider...

They cost a fiver now

I have one bike with the Octalink BB. I needed to buy a new crank puller for it, but found one pretty cheap on ebay which is of perfectly decent quality
https://www.ebay.co.uk/itm/Bicycle-Bike ... 2749.l2649

FWIW, It also happens to work (without the additional loose plug on the end) for an old Tange square taper BB where the spindle has a built-in threaded end, rather than the threaded holes for the usual BB bolts....

[simonineaston]

So I have a frame which was fitted with a Stronglight 'Activ' triple chainset and very nice it is too, although I'm not going to use it on my lastest build project, so off it came and I search for a suitable tool to remove the bearing cups. Bit of digging on the internet and I put 2 & 2 together and work out that the bearing cups will take a Shimano tool made to work with their 'Hollowtech' bearing cups. I have one
For the sake of this arguement, we'll call these bearing cups 'Hollowtech-shaped'. As both the Stronglight bearing cups still on my frame and the bearing cups supplied with the new Shimano cranks are 'Hollowtech-shaped', I fondly imagine that they accord to the same standard... So, that got me thinking. If both sets of bearing cups are 'Hollowtech-shaped', can I just pop the new (Shimano) cranks into the old Stronglight 'Hollowtech-shaped' bearing cups?? I bet the answer is No. I bet they do not share a standard at all!!

[Brucey]

BB cups for cartridge bearings vary in internal diameter etc. They might turn out to be compatible.... but you shouldn't take it for granted, eg FSA cups look about the same but don't interchange with shimano; the difference in diameter is almost too small to measure.

cheers

[Sweep]

If you currently have a crank extractor it may be compatible with both ST and Octalink BBs.

For whatever reason I ended up getting a fiddly little ‘plug’ to use with my ST extractor: TL-FC15. Something to consider...

They cost a fiver now

I have one bike with the Octalink BB. I needed to buy a new crank puller for it, but found one pretty cheap on ebay which is of perfectly decent quality
https://www.ebay.co.uk/itm/Bicycle-Bike ... 2749.l2649

FWIW, It also happens to work (without the additional loose plug on the end) for an old Tange square taper BB where the spindle has a built-in threaded end, rather than the threaded holes for the usual BB bolts....

I can also recommend this crank puller for octalink and square taper.
Branded lifeline but was Xtools - not sure why branding changed.
https://www.chainreactioncycles.com/lif ... -prod10181

[reohn2]

I grew up at time when adjustable BB's were the norm and found they were OK.
Along came sealed BB's and I found these extremely long lasting and maintenance free, a huge improvement.
Looking at a bike on offer it comes with an Octalink BB.
I have no experience of these and wonder what are the pluses and minuses over the square taper I'm familiar with.
I guess a whole new load of tools would be needed to change one?

My experience of Octocrap was solved on our Cannondale tandem by changing the cranksets to Stronglight Impact tandem set when the Octocrap failed at 6k miles.
I priced up decent quality SKF Octolink BB's and found it cheaper to change the chainsets once I'd sold the old Octo's on Ebay
SinL had one on his commuter which died early and I swapped it for S/T,problem solved.

You could buy the bike,run it until the BB dies then swap to S/T there's lots of S/T bargains out there,not least Spa's own offerings

Thread drift alert:-
I've compained long and hard about external bearing BB's(EBB),and the Deore one fitted to my Longitude died at less than 800miles even though I stripped on purchace pumped it with more Shimano greasd and torqued it up properly.
I replaced it with a Token EBB which is still as smooth as silk and spins as good as a S/T when the crank is flicked with the chain off.
SInL's Vagabond is fitted with a Shimano XT EBB which is lasting well much to my surprise as his service regeme is 'when it makes funny noises take to FinL'

My 2d's worth.

[francovendee]

You could buy the bike,run it until the BB dies then swap to S/T there's lots of S/T bargains out there,not least Spa's own offerings

I have almost come to the same conclusion. Off to try the bike next week, if as they say it's in stock.

[rjb]

Shimano are also guilty of changing the spec of there square taper installation tools as i discovered here.
viewtopic.php?f=5&t=125896&p=1286081&hilit=shimano+bottom+tool#p1286081