This type of BB was common amongst early cheap square taper chainsets. Rather than bolts to hold the cranks on, it used nuts. I had a bike with a SR chainset like that in the 70's. As said above, I just used a standard crank extractor screwed out a bit further.
This type of BB was common amongst early cheap square taper chainsets. Rather than bolts to hold the cranks on, it used nuts. I had a bike with a SR chainset like that in the 70's. As said above, I just used a standard crank extractor screwed out a bit further.