Unknown bottom bracket
Posted: Wed Mar 13, 2013 2:44 pm
Hi All
I've been given the task of rejuvinating my mother-in-law's bicycle
She's had it since new and finds it comfortable, but I've been finding some really obsolete bits and pieces on it (as in, parts that weren't around for long, and were not high end at the time). I've figured out ways around most things, until I got to the bottom bracket. I measured the shell at 70mm. Goodo; possibly Italian, probably not though. Taking the crank off, I noticed that the square taper is bigger than JIS/ISO. Oh well, I'll replace the BB and the crankset with a JIS one, I thought.
I couldn't get the drive side to budge, so I got stuck into the non-drive side and was quite surprised with the way it came apart. The lockring was more of a sleeve than a standard lock ring, and removing the non-drive side cup I found what looked like a sleeve wedged into BB shell. There are no threads cut into the shell itself. Some gentle persuasion with a drift and a hammer and the whole sleeve popped out, with the drive side cup still in the sleeve. I haven't got a vice, so am struggling to uncouple them. It's also difficult to determine the thread direction on this side. Looking at it, it appears to be a RH thread. I'd be surprised if this was correct, but it would fit in with all of the other odd stuff going on with this bike.
So anyway, what have I got here? And what are my options to rebuild? Service the existing setup and try to find a 106BCD 3-arm chainring to replace the worn one? Replace with...?
Ta
I've been given the task of rejuvinating my mother-in-law's bicycle
She's had it since new and finds it comfortable, but I've been finding some really obsolete bits and pieces on it (as in, parts that weren't around for long, and were not high end at the time). I've figured out ways around most things, until I got to the bottom bracket. I measured the shell at 70mm. Goodo; possibly Italian, probably not though. Taking the crank off, I noticed that the square taper is bigger than JIS/ISO. Oh well, I'll replace the BB and the crankset with a JIS one, I thought.
I couldn't get the drive side to budge, so I got stuck into the non-drive side and was quite surprised with the way it came apart. The lockring was more of a sleeve than a standard lock ring, and removing the non-drive side cup I found what looked like a sleeve wedged into BB shell. There are no threads cut into the shell itself. Some gentle persuasion with a drift and a hammer and the whole sleeve popped out, with the drive side cup still in the sleeve. I haven't got a vice, so am struggling to uncouple them. It's also difficult to determine the thread direction on this side. Looking at it, it appears to be a RH thread. I'd be surprised if this was correct, but it would fit in with all of the other odd stuff going on with this bike.
So anyway, what have I got here? And what are my options to rebuild? Service the existing setup and try to find a 106BCD 3-arm chainring to replace the worn one? Replace with...?
Ta