iso or jis threaded headset?

Hi,
I am currently working on my first ever bike build, it's going to be a Gazelle AA Special single speed for going around London on. I have already made a fair few mistakes!

I have just discovered that the Camapagnolo headset I have fitted is probably not the right one. I have stupidly fitted the cups only to discover the crown race is too small to fit over the fork. After researching a lot I have discovered that a JIS crown race is .6mm wider than the ISO. I just want to make sure I have this right before I waste another £50.

(If you want to know the other things I have got wrong; I bought a bb with too long casing and a crankset in which the chain wheel was bent)

Best thing I ever bought. Digital Verniers.

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Sheldon Brown's crib sheets are a great resource, the one about headsets is here. The actual building of a bike is quite easy, the hard part is making sure all the parts will fit together.

I'm a little confused here: a Gazelle will use an ISO standard headset, which is what your Campag HS should be.

Even if the crown race was JIS (did you buy the HS second-hand, the parts could have become mixed-up) it would be loose on an ISO fork crown.

So either the forks aren't original and have a JIS standard crown, or you're confusing what should be a tight, interference fit with being the wrong size.

The crown race shouldn't fit easily over the fork crown and you will need a crown race setter to get it on.

The tolerances are quite fine so if all the parts should fit but don't (paint on the fork crown for example), then you could take some Emery cloth to crown/race.

As suggested above, get some Vernier calipers: easy to read digital ones are a fiver or so off of eBay. Until you know exactly what you're dealing with, you won't know exactly how to deal with it!

@Scilly.Suffolk yeah, I have since been on that crib sheet v. helpful. I am certain this is the correct fork. Well I though Gazelle would use ISO but I am certain that this crown race will not go on. I tried everything to get on, this surpasses interference fit, I managed to get the cups on after all! I have done some research and seen a few of the eighties Gazelles with Tange headsets, which strangely sit between JIS and ISO with a cup measurement of 30 and a crown race of 27. I am looking at this as my replacement http://www.ebay.co.uk/itm/281729721127?_trksid=p2057872.m2749.l2648&ssPageName=STRK%3AMEBIDX%3AIT.

What tool are you using to fit the race?

Both ISO and JIS have frame cups with an OD of 30.0mm, so if the race is 27.0mm then it's a JIS HS, not something halfway between the two.

Tange make both JIS and ISO HS: how do you know what the Gazelles you found are using? Not saying you are wrong, just curious.

Either way, I suggest you measure the race and the crown before spending any more money: the calipers will prove invaluable in the long run and pay for themselves many times over.

PS @boydsbikes is on here so if you do need that HS, ask nicely and you might get a forum discount...

Yes, your right. Sorry, I read a misleading post on some forum saying that JIS was 30.2 but obviously thats not true. The calipers are a must I guess, annoying because it's yet more money.

Ah! 30.2mm is Italian.

It was (and still is) common practice for bike shops to sell rebadged bikes and even some quite large brands.

The Dutch had strong links with the Italians, so it's not unusual to find "Dutch" bikes with Italian standard headsets and bottom brackets, because they were built by Italians.

Maybe you need an Italian headset, not JIS: Italian HS had either a 26.5mm or 27.0mm crown race.

What BB did you buy and why didn't it fit? ISO shells are 68mm wide and ITA 70mm...

This is the Gazelle thread on here: have a read.

Big discount if you buy from the website:

http://www.boydsbikes.com/#!product-page/c1iym/80cc02f9-1770-1707-90a7-d19f7de77879

Thanks for the heads up.

I have a TG235 (JIS) headset that a customer has returned if anyone wants one at a discounted price?

20% off website price (+post)