thehammerdog

I want to upgrade my old Crankset and BB but not sure how to determine what I currently have. I know there is now a half dozen sizes and styles so what is the trick?
2007/2008 Bianchi c2c 928 FSA gossamer with external BB cups

TimothyH

Best bet is to pull it apart and ID the actual bottom bracket parts.

My guess is that this bike comes with an english threaded BSA bottom bracket shell. Almost certainly if it is 10 speed.


-Tim-

Eggman84

You have a 2007/2008 FSA Gossamer crankset with external BB cups. Most likely a 68mm BSA threaded BB shell. Suggest you remove the crankset and one of the cups to verify. Should not take but 10 or so minutes assuming you have the tools. If you don't have the tools, take it to your LBS and they will properly identify what you have and make some recommendations on replacement. Finally, inquiring minds want to know why you are wanting a new crankset.

ksryder

It's an FSA Gossamer-- I think that pretty much explains why he wants to upgrade.

Iride01 

I'd agree it's probably english threaded BSA. So that means it's 1.37inches Diameter threads with 24 threads per inch. Be very careful not to confuse a 1.375 inch x 24 TPI because that is Italian threaded and that .005 inch does usually make a difference though I sure someone here probably tried and it worked for them.

The other thing you need to know is the BB shell width. The mfr or google search might find that but you also can find that out by taking it apart and measuring the width of the shell from one side of the bike to the other side. Usually you need that measurement in millimeters. Some BBs are made for a specific width and others are designed for a narrow range of width.

You also need to know what your crank is. And then you have to find an English threaded BB of the proper width that also fits your particular crank or the new one you might purchase.

What are you expecting from upgrading the BB? If it's working and you are okay with the current cranks you really won't gain much, except maybe the knowledge of how to change one.

thehammerdog

Bike
Indeed
well I suppose the thing needs grease or bearings or something plus i want a nicer lighter set cannot afford nee bike so figured why not make this upgrade

shelbyfv

I think Italian bbs are threaded opposite so you are unlikely to confuse them. Current Shimano cranks with HT II all use the same bb, though there are several group levels to suit your budget. I'd suggest a current Shimano crank that matches the rest of your components.

JohnDThompson 

No, 1.375 x 24tpi is ISO thread, and compatible with English. Italian is 36mm x 24tpi, and an English or ISO cup will simply fall into an Italian thread shell without engaging any threads.

English and ISO thread shells use standard thread on the non-drive side, and reverse ("left-hand") thread on the drive side to prevent precessional loosening. Italian thread shells use standard thread on both sides. As noted above, an English or ISO cup will simply fall into an Italian thread shell without engaging any threads.