Catnap 

I’m building up a Kalavinka road frame and the fork uses a JIS 27.0 crown race. I’d like to build the bike with a vintage Tange Levin aero AR-202 headset because it will match the NITTO Crystemblue stem I’m using. However the only AR-202 headsets I see on the market come with ISO 26.4 crown races. They also made versions with JIS crown races but they are even rarer and none are available on the secondary market currently. Yes, I could mill down the fork to accept ISO crown races but I’d rather not alter the frame.

My assumption is that the ISO and JIS versions are identical except for the crown race inner diameter. I’m considering buying an AR-202 and swapping the crown race for a JIS one, but I know not just any one will fit. I was wondering if anyone had a Tange AR-202 on hand and could tell me if any other Tange headset crown races are interchangeable with it.

Catnap 

Bump... hoping someone here might have this knowledge

unworthy1

I don't have the knowledge but do have a few ideas: the AR-202 appears to use caged bearings which might be common to other Tange HS, plus pix show a fairly non-exotic looking (steel) crown race so my guess is you might see a visual match by comparing with other (Levin models) races, the only thing distinctive to my eye is this AR-202 race is thicker than some (such as a Passage).
I'd say count the bearing balls and start looking at Tange HS (in person or good "exploded" pix), I think a good chance you may find a match in 27.0





BUT just remembered there's one more detail: the cups that come with either 26.4 or 27.0 races are often sized for either 30 or 30.2 headtubes, so do some checking into that especially before dropping big $$$ on a rare HS

embankmentlb

I don’t have a solution but sounds like a you have some cool bits to work with!

Catnap 

Thank you unworthy1 for the good ideas! I agree that’s the way to go about it in the absence of having one of these headsets on hand. The one seller on eBay who has several NOS examples lists them as being for BMX but says the head tube size is 30.2, which is for a road bike. I saw one on Yahoo JP with a 27.0 crown race, so I know they exist although I didn’t win that auction.