Bicycle Mechanics - Bianchi Stelvio BB upgrade

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : Bianchi Stelvio BB upgrade

debecker13
04-30-04, 01:55 PM
I am rebuilding a Bianchi Stelvio steel frame, and attempting to upgrade the components with a used ultegra group. My problem is that the original bottom bracket from the bianchi is a larger diameter than the new ultegra bottom bracket. Are there any suggestions for making the ultegra double crank work. I would prefer to use as many parts as I can from the ultegra group I have now.

demoncyclist
04-30-04, 02:04 PM
BBs are cheap. Just buy the right one.
debecker13
04-30-04, 02:27 PM
BBs are cheap. Just buy the right one.

My question is what bottom bracket will work with an ultegra crank set when then ultegra bottom bracket is not the correct diameter for the bottom bracket shell on the bianchi?

demoncyclist
04-30-04, 07:14 PM
They come in different sizes for different bottom bracket shells. My guess is that your Stelvio has Italian threading instead of the slightly smaller, and much more common (on today's bikes) English threading.
Retro Grouch
05-01-04, 09:21 AM
I am rebuilding a Bianchi Stelvio steel frame, and attempting to upgrade the components with a used ultegra group. My problem is that the original bottom bracket from the bianchi is a larger diameter than the new ultegra bottom bracket. Are there any suggestions for making the ultegra double crank work. I would prefer to use as many parts as I can from the ultegra group I have now.

You appearantly need an Italian threaded bottom bracket. Shimano bottom brackets are available that way. Getting one shouldn't be a big deal. Be sure to use a torque wrench to install it because it has all right hand threads and it takes more torque than most people will intuitively use to keep it from coming loose in use.
John E
05-01-04, 09:45 AM
Italian: 36mm diameter x 24 TPI, RH thread on both cups
French: 35mm diameter x 1mm, RH thread on both cups
Swiss: 35mm diameter x 1mm, LH fixed cup thread
English/ISO: 1.375" = 34.925mm diameter x 24 TPI, LH fixed cup thread
olde Raleigh roadster: 1.375" x 26 TPI, LH fixed cup thread

Having experienced alot of trouble with self-loosening fixed cups on Bianchis and Peugeots in the past, I always LocTite the fixed cup threads of (self-loosening) Italian and French BBs.

Personal editorial: It is unfortunate that Swiss BB threading is obsolete and rare, as this was the only correctly engineered standard which was also purely metric.
debecker13
05-03-04, 03:32 PM
You appearantly need an Italian threaded bottom bracket. Shimano bottom brackets are available that way. Getting one shouldn't be a big deal. Be sure to use a torque wrench to install it because it has all right hand threads and it takes more torque than most people will intuitively use to keep it from coming loose in use.


Thanks for all the responses... I was just in need of an Italian BB. I was unaware of Italian BB's being a different diameter, I only thought the threading was different. Thanks again, the bike is running smoothly, looks classic....