B17

I'm in the midst of buying a Tange Passage headset, and I'm not yet sure which size my crown race is, and I have no digital calipers to measure. eBay offers both size headsets and both crown races separately, so my plan is to buy one complete headset and a crown race in the other diameter, and use whichever crown race fits my fork steerer. That should work so long as all the other parts are the same on both size headsets. Are they?

Thanks in advance!

Moe Zhoost

The Japanese standard is 27.0, while 26.4 is common on high end Italian bikes. When in doubt, the best thing is to measure. There are plenty of inexpensive digital calipers on the market so you should buy a set at earliest opportunity. To answer your question, either crown race will work with the other headset components.

dedhed

Yes, buy the extra crown race and use the one you need. Totally exchangeable. Make sure the stack height works for you.

Crankycrank

I vote for getting some inexpensive digital calipers. You'll eliminate the cost of 2 headsets and calipers will come in handy for many other uses for your bicycle and other things. It's always a good idea to measure the frame surfaces before installing a headset anyways as sometimes the original was installed on a frame not within specifications (out of round, too tight, etc).

dedhed

While I agree a cheap set of digital calipers is a basic bike tool, he's not looking at purchasing 2 headsets, just an additional crown race. Plus he doesn't have to pull anything apart until the parts arrive.

Fissile

Cheap Hazard Fraught calipers are your answer. I have a set of these and I've compared them to much more expensive calipers.....the HF are dead on.

With a coupon you can get these for around 15 bucks. More than adequate for DIY bike mechanics.

https://www.harborfreight.com/6-in-D...per-63711.html

HillRider

Along with crown race diameter differences, the cups of JIS and ISO headsets differ. JIS press-in cups have an OD of 30.0 mm while ISO cups are 30.2 mm OD. A JIS cup will be a loose fit in an ISO headtube.

Get a decent pair of calipers and measure your bike frame and fork before ordering. At a minimum, tell us the make, model and year of your bike and we may be able to make a more informed suggestion.

Fissile

There are some mixed 1 inch headsets that are made with 30.2mm cups (ISO) and 27mm crown race (JIS). This is pretty good quality but on the heavy side.

https://www.ebay.com/itm/Tange-Levin...4383.l4275.c10

B17

The frame is a Bianchi Osprey, Superset 2 lugged. Not sure what year atm (probably early 90s)- it's not here at my home, but across town, stripped to bare metal and primed, waiting for me to shoot it in celeste. It was originally black with these decals (this is the eBay photo)



I'm getting the new HS because the difference between the steerer tube and the head tube is only 34mm, but the headset that came installed is a Hatta Vesta, which I googled at 38mm without the Dia-Compe hanger. It should not have fit at all, and I wasn't thinking about this when I removed the top cap and had the cups removed. In my paranoia, I'm thinking I may have only a Hatta top cap and the rest is from some other headset. I didn't look to see how much thread was remaining when I took it apart because there was no reason to suspect anything. I don't want to have to have my LBS put all this together and find out I didn't have enough thread to begin with, so I'm starting fresh with the Passage, which is 30.something mm and will work with a standard cro-moly hanger.