I have a really nice, older, carbon octalink chain set sitting in my garage doing nothing. I may as well get some use out of it on the winter road bike but am unsure what length BB to get for it.

It’s a road C/set, double, 39/53; am I right in thinking that I will need a 109mm BB?

BB

It does depend on the frame and chainline but my Planet-X Superlight had a 109mm Octalink BB.

Yep, a 109 should do the trick. Got one in my Planet X and Cervelo.. 😉

for those old enough to remember the system

😯

One of my road bikes has a Dura Ace Octalink c set on it. The system isn’t that old though replacement BB’s aren’t cheap these days.

Oh and I concur with 109mm for a double C set.

109 for double, 118 for triple. It was that simple 😀

The system isn’t that old

Superseded in 2004, that’s pretty old! Agree I’d expect most to remember them though!

Thank’s guys.

I only put about it being old as I was surprised that I can’t find any seller selling anything other than the 105 BB, thought there would still be plenty of Ultegra/DA available at discount prices!

BB

thought there would still be plenty of Ultegra/DA available at discount prices

it seems that once stuff stops being specified as original equipment on new bikes and existing stocks at bike manufacturers/discount places are exhausted it all goes back to full retail with not much discounting to be had.

Shimano discontinued the Ultegra version a few years ago hence why you are struggling to find one.

To be fair there was no reason to keep going with Octalink, HT2 was lighter, cheaper, simpler and more durable! Those adjustable DA BBs were a PITA!

How were the Dura ace octalink bbs adjustable? Genuine question – i’ve just bought one to go on my winter bike. As far as i can tell it’s a non-serviceable cartridge unit with a fixed drive side cup and a loose nondriveside one.

There were some Dura Ace BBs that were servicable, see HERE

Finbar out of interest what number is on your BB shell? BB-7700 or BB-7710?

finbar, you don’t adjust them, they are a sealed unit.

I’ve got Octalink on an old MTB and quite like it, seems pretty durable, stiff enough as well.

finbar, you don’t adjust them, they are a sealed unit

As said, not all of them were, the BB7700s had 2 sets of needle bearings with a couple of lockrings, they did last forever, but could be a bit of a ballache to service. These days I’d be surprised to come by one of those though!

7700. This one:

http://www.ebay.co.uk/itm/230674665772?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Maybe it is servicable then. That is, if i can get the lockrings off in a year or so’s time 😆

I’ve still got ISIS. 😳

ISIS FTW, brassneck.

That looks like a servicable one to me. But I haven’t seen one in a while.

I still have ISIS and Octalink BBs / Chainsets running fine, they’re far from obsolete.