Sorry if this has been covered before, but I was wondering if anyone has any info on these cranks? I picked up a pair today on a 1977 Carlton track bike. They are the 5 bolt no spider variety mated to a TA ring and spider. Theres a good chance they were taken off another bike to be used on this one, so the date probably doesnt mean much. I couldnt find a single other marking on the cranks, not even a length.