Diamond

With the range of bottom brackets offered these days, I guess this is a common question. I have to say I'm confused. I have a 2005 Specialized Tarmac and the specs I have for it say the following for the bottom bracket: "FSA CK-8680". That sounds like a model number rather than a type of bottom bracket. But just to confuse things, when I bought the bike, compact cranks were just coming out so I had them swap in a compact crank an FSA Gossamer. I'm assuming they didn't change the bottom bracket but maybe I'm wrong? I'm attaching a picture of the bottom bracket to this post. From the info provided can anyone tell me what bottom bracket this is or are there simple measurements I can do to confirm what type it is?

Related to this, any chance my new two piece FSA 386 EVO Gossamer crank will fit in this bottom bracket? Well clearly the current spindle would not work but would the bearing cups work with two piece 386 crank? Or are there adapters I can buy?

Thanks for your assistance!

-Scott

HillRider

I believe you have an ISIS cartridge bottom bracket, a splined type similar to but not identical to the Shimano Octalink. They had a mixed reputation for reliability, some being decent and others dreadful. In any event they are obsolete and mostly found NOS or used.

A two piece crank will not work with that bottom bracket and, since it's a cartridge, the entire thing is basically one piece and has to be replaced as a unit.

Brian25

"greasy"

Diamond

Thank You!! The crank arm has ISIS drive printed on it (bad name these days) so that supports your statement. I'd never even heard of that type before. Since you answered that question so quickly ... may I ask ... if I bought a new crank/bb how can I tell what would be compatible with my frame? Given my bike is 9 speed, this may approach new bike day instead of upgrade but I thought I'd ask.

HillRider

A Google search for your bike indicated it has a standard 68 mm English threaded bottom bracket shell so any English threaded bottom bracket and matching crank will work.

I also looked up your FSA 386EVO Gossamer crank and FSA does make an English threaded bottom bracket for it with FSA part number 200-3201 so if you get the appropriate bottom bracket the crank will work on your bike.

Diamond

Now that's what I'm talkin bout!! Thank you very much. I see I can pick up a BB for about $50. I'll definitely do that.

pesty

I can confirm this is a standard 68mm English threaded BB. I have an '05 S-Works Tarmac and I've used both Truvativ/SRAM GXP and Shimano Hollowtech II bottom brackets in this bike. If you go with FSA, their Mega-EXO BB is very similar to these and should work fine. [edit] Just noticed the 386EVO part, but yea, Hillrider's suggested BB should work[/edit]

Bike Gremlin

You might be able to use the new 2-piece crankset with your bike - with an adapter. Wrote a few articles on BB-s. Some explaining each type (with pics for identification), some with compatibility charts for mix-matching. This is the link:

bottom-bracket

How to "convert" the frame:

HillRider

He doesn't need any "adapters since his frame is English threaded. All he needs is the correct bottom bracket from FSA. If he want to use another crank, any Shimano Hollowtech II or other two-piece one can be had with English threaded bearings.

Bike Gremlin

Didn't he mention FSA 386 EVO Gossamer crank?

HillRider

Yeah but FSA sells a bottom bracket for that crank that is English threaded so it's proper for his bike. It would be different if his frame had a BB360EVO bottom bracket shell. The English threading also, of course, allows a host of other make cranks and bottom brackets.

Bike Gremlin

The BB is the one from the video I've linked? We are talking about the same thing?

HillRider

Yes it is and yes we are.