Is this bottom bracket interface (bb tube) original or did the previous owner cut and weld something special to fit the bottom bracket?
by Dialed_Inn
Is this bottom bracket interface (bb tube) original or did the previous owner cut and weld something special to fit the bottom bracket?
by Dialed_Inn
2 Comments
That would be an eccentric bottom bracket, it’s a real thing but if it’s the original spec one I’m not sure!
Nobody transplanted an eccentric bottom bracket into an aluminum frame. That would be a massive undertaking, and they certainly would not have put the original Cannondale warning sticker back on the downtube after doing so.
These eccentric bottom brackets have a tendency to seize. I would take it out, put a thin layer of copper or aluminum (doesn’t matter) anti-seize on the shell interface and the bolts, being careful not to apply so thick that it could ever get on the crankset spindle and contaminate the bottom bracket bearings, and reassemble.
One *could* use it to make *marginal* changes to the chainstay/seat tube geometry, but we’re talking extremely marginal, and on a bike with extremely short geometry by modern standards and a “sloppy” fork. It’s a real princess and the pea situation and nobody would notice the geometry changes in real life.