I need a square taper bottom bracket for a vintage Campy crank. Sheldon Brown says there are two types of spindles (JIS & standard) that are not compatible.

Does anyone have a source for relatively inexpensive standard BSA BB's? White Industries makes one, but it is $152!

JIS and ISO Campy is ISO

some ideas

https://www.universalcycles.com/shop...&category=4716

https://www.universalcycles.com/shop...&category=3166

here is sheldon on tapers

https://www.sheldonbrown.com/bbtaper.html

ISO/J.I.S. Interchangeability

If you install an ISO crank on a J.I.S. spindle, it will sit about 4.5 mm farther out than it would on an ISO spindle of the same length.ISO crank on J.I.S. spindle -- small square-taper hole in crank
places it farther outboard on the spindle.



Conversely, if you install a J.I.S. crank on an ISO spindle, it will wind up about 4.5 mm farther in than it would on a J.I.S spindle of the same length.

Theoretically, ISO cranks should only be used on ISO spindles, and J.I.S. cranks only on J.I.S. spindles.

In practice, you can very often get away with mixing these sizes, as long as you select a spindle length that gives the desired chainline.

Taper matching was fairly important back in the day of loose-ball cup-and-cone bottom brackets, because these required regular maintenance/overhauls, and this required removal of the cranks. Every time you remove and re-install a square-taper crank, the hole in the crank is liable to get very slightly larger.

This was particularly an issue when using J.I.S. cranks on ISO spindles, because over time, as the crank went on farther and farther, you could run out of taper, and the square end of the spindle would become flush with the surface the crank fixing bolt/washer pushed against. At that point, further tightening of the bolt won't make the crank any tighter, since the bolt is bumping onto the end of the spindle.

Tolerances on older spindles may not be closely held, and dimensions may vary enough even with the same model number to affect crank/spindle compatibility.

If the end of a bolt-type (hollow, internally-threaded) spindle is too small, it may be ground down, as long as the spindle does not bottom out on the back of the crank and the spindle's internal threads are long enough to hold the bolt.

I (Sheldon) generally avoid mixing sizes on customers' bikes, but I have a lot of experience mixing ISO/J.I.S. in both directions on my own personal bikes, and it has never given me a lick of trouble.
These days, however, most folks are using sealed cartridge bearing bottom brackets. With these, installation is quick and clean. No routine maintenance is required, so typically the crank will be installed once, and will stay in place unless/until the bottom bracket needs to be replaced. This greatly reduces problems of wear to the interface. Phil Wood cartridge bottom brackets are the ticket when replacing older spindles because, uniquely:

• they are available in all three tapers, different offsets and several lengths,
• their right-left position is adjustable,
• mounting rings are available for all common threadings.

I have a Chin Hur off eBay in ISO that works great and was $18. Miche is another good source.

Thank you !!