Lockring for ISIS Bottom Bracket?
 

Hi,

I'm swapping out a Truvativ ISIS triple crank for a Shimano Ultegra double on my '05 Cannondale CAAD7. I picked up a Shimano Octalink V1 BB to go with the new crank.The ISIS BB that is on the bike at the moment appears to have some kind of lockring holding it on. As far as I can tell, the Octalink bottom bracket that I will be replacing it with does not have a lockring and is held in place by the retaining cups on each side. My question is: do I need a lockring spanner to take this thing off, or will a large pair of channel locks suffice, since i won't be reusing the lockring once it is removed?

Thanks!

I have ISIS BBs on two bikes, including an 04 CAAD7, neither one uses a lockring. I think what you are seeing is the cup. ISIS cups are not like shimano, they have notches around the outside edge that the BB tool grabs onto, while shimano cups have notches machined inside the face of the cup for the tool to seat into. What you need is an ISIS BB tool like those in attached. http://www.shopwiki.com/search/TRUVA...BRACKET%20TOOL

I have both. The PARK BB18 is strurdier and I find it grabs onto the notches better than the Truvative BB02. Howvere, you can't use a torque wrench with the Park tool unless you rig up something funky. So I do most of the work of removing and installing with the Park tool, then do final torque with the Truvativ. Since tightening is not relevant to you since you are switching to shimano, go with the Park BB18.

If I had to name one thing that makes Shimano Octalink preferable to ISIS BBs its the cups. Shimano cups are just easier to install and remove because the tools grab onto and hold the cups more securely. But I kinda like my Truvativ Rouleur cranks, so I live with the ISIS.

I cant see what you have but I suspect that its a Truvativ ISIS BB and it has a O-ring spacer, not a lock ring. Truvativ ISIS BB's require their own tool to remove and the cups on them have a pattern not unlike a lock ring. Its annoying to need a special tool for a one off removal but I suspect thats where you are at. Its times like these where having a relationship with a local bike store is useful.

Anthony

I have both a BBT-18 and the Truvativ tool. I found the Park version to be utterly useless for installing the cups for two reasons:

1. The fit was terrible. Because the ID was too large, the teeth barely engaged the cups at certain points. I thought I was going to ruin the cups with that tool.

2. The 8 sided protrusion on the rear of the tool can only be grabbed by a big adjustable wrench (or similarly sized normal wrench but I didn't have the right size). Why Park did not put a hex on the back of the tool is beyond me.

Anyway, I found the Truvativ tool to be excellent. It fit snugly with no sign of play (actually it fit so tight I almost thought it didn't fit at first) and the 1/2" square drive made using a torque wrench as easy as it should be.

Side note: I think it's only Truvativ that uses the 8 notch cups for their ISIS BBs. My other bike has an FSA BB and it uses standard internally splined cups. I'm pretty sure both the Stronglight and American Classic ISIS BBs I was originally considering also used internally splined cups.

Wow, this clears it up, thank you everyone. It seems a little idiotic to buy another tool for a BB that I'm getting rid of, so I'll probably take it to a bike shop around here for removal. I had assumed that the splined Park Tool BB remover that I had would fit both the Octalink bracket and the Truvativ BB but apparently it only fits the former. Thanks again.

I've had the opposite experience. My BB18 teeth are a bit bigger than the teeth on the truvative version so seem to fit and hold the notches more snuggly; while the truvative tool sort of sildes around a bit when engaged. That said, I do agree that the fat 8 sided wrench flats are a pain to deal with.

Yes, I should have been clearer. Its the Truvativ ISIS cups that have the 8 notch cups.