Adjustable cup bottom brackets use a locking ring to secure the adjustable cup against the frame, and that ring requires a pin spanner to install or remove properly. The Park Tool SPA-1 handles this job with a straightforward design: two hardened steel pins sized to fit the holes in standard locking rings, connected by a comfortable handle that gives you the leverage to snug things down or break them loose.

The pins sit 48mm apart center-to-center, which matches the hole spacing on most adjustable bottom bracket locking rings. You'll find this style of bottom bracket on plenty of vintage road bikes, some track frames, and various fixed-gear builds where riders prefer the serviceability of cup-and-cone bearings over modern cartridge units. The pins themselves are 2.2mm in diameter—sized to engage the locking ring holes without slipping out under load.

Using the SPA-1 is simple enough: seat both pins in the locking ring holes, apply pressure toward the frame to keep them engaged, and turn. For installation, you're tightening the locking ring against the adjustable cup to hold your bearing preload in place. For removal, you're backing it off so you can access the adjustable cup beneath. The handle shape keeps your knuckles clear of the frame while you work, which matters when you're applying real force in a tight space.... Read More