You are reading a single comment by @Jonny69 and its replies.
Click here to read the full conversation.
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
Jonny69
Some hopefully non-dumb answers (but watch out, I may be just another uninformed chopper).
1) I've seen some ISO headsets advertised as NJS. Not seen them in the flesh, though. I had thought they would only be certified if they were JIS. Headsets should be stamped JIS (27/30) or ENG/ISO (26.4/30.2).
Stacks should be similar, but not necessarily identical. My two NJS frames have about 0.3mm difference in the amount of stack needed.
Someone had bodged ISO cups and a JIS crown race into my Makino. The dodgy interface chewed the crown and took some fixing.
2) Yes, 68mm shell, BSC/ISO thread. But always check if someone has messed your threads.