[mccett]

Sorry for the stupid question but i'm a bit old school and have always used square taper BBs with Middleburn RS7s (what? says all the overseas viewers - they're british and strong!).

Anyway, new frame (Demo 8) comes with a Truvativ ISIS Giga Drive BB so i figured i might get into the 21st century and get some new cranks but am confused by the new BB shapes...(apologies if they arent that new, i've been away a while)

I think ISIS and ISIS Giga drive might be the same and just a name Truvativ give their ISIS cranks, but octalink?? I see Shimano use those as well... is this as well as ISIS?

AAARRGGHH!

Please Help - i want to build my bike! cheers
Mc

 

[chicodude]

If I am correct, I do believe the ISIS and Octalink are different.


I think ISIS and ISIS giga are the same.

 

[Wumpus]

If I am correct, I do believe the ISIS and Octalink are different.

Yep, they are different.

There are two kinds of octalink(1 & 2). The owner of the LBS told me that Octalink 1 is only for older xtr and the rest of shimano uses octalink 2.

 

[binary visions]

Octalink is different than ISIS and is Shimano's propriatary take on a splined interface. Different spindle size, different spline pattern...

I'm sure Truvativ's website will tell you what "Giga Drive" is, I've never heard of it.

 

[Wumpus]

Probably more than you want to know: http://velonews.com/tech/report/articles/6799.0.html

Page down to the third response.

 

[mccett]

Cheers guys, that helps a lot. ISIS = everyone else. Octalink = Shimano being awkward. No change there since i've been away from the sport!

Off to find some nice cranks now.

Thanks a lot.
Mc

 

[Stinky Boy]

I read an article about a year ago that Shimano was asked to be part of the ISIS program but did not want anything to do with it. I think that if Shimano became part of it, it would be alot better for us! Just a thought.

 

[Silver]

Wasn't Shimano first on the block with splined cranks?

 

[sama1ter]

Wasn't Shimano first on the block with splined cranks?

yes with 5 letters

 

[Spunger]

They are both different but very much the same. Having multiple contact points on the arms. I don't think octilink needs such a tight taper fit like ISIS cranks do.

I think you'll see Shimano stick with the external BB idea as well as Truvativ and Raceface. That idea sloves problems that have plagued bikes for years. You haven't seen a Saint crank snap yet, or any other of those external BB deals. They might have to work out some bugs on the bearings and such but that's not a biggy. I like that idea a load better than the current ones.

 

[JRB]

The giga may have a bigger spindle, which means a smaller bearing. I can't wait for the fsa exo isis to come out. Should be next month. I've had several failures or loose spindle/bearing interfaces with truvativ giga pipe sls.