1= 30.4mm
2= 25.4mm
My forks are Tange chromoly straight track forks
Crown race from BB set fits forks just fine.
When Sheldon talks about ‘frame cup outside diameter’ what is he talking about exactly?
I am assuming that the fork is threaded. Is it?
If it is then an internal diameter of 30.4 is close to 30.0
and the steerer tube is a standard one inch
this means that it is probably a 1 1/8 inch threaded headset.
If you search on the internet you should find one for under 30 dollars plus postage
But I would strongly suggest you take it in and get a decent bike mechanic to look and see if that is true and make sure there is no other reason for the increased diameter.
I think that is as far as my advice can take you on this
fullface
Sorry azz now I am being a smartass. Missed the thread with the one inch threaded information
apologies
full face
try search 1 1/8 threaded headsets and see what you get
Good luck full face
Your problem is you’re probably matching up tapers incorrectly. I’m guessing your shimano 110mm BB is not a track BB, so will be a JIS taper. The Sugino Grand Mighty is a proper track crank so is ISO.
The problem you have is you’re mixing an ISO taper crank (Sugino Grand Mighty) with a JIS taper Bottom Bracket. That would account for the 4.5mm of offset chainline problem.
You need a 109mm ISO BB for a perfect chainline. Lke a sugino 75 one, or similar!!
Hope this helps…
Sheldon Brown RIP explained it well!
Is this the same as a BMX headset?
Isn’t 1/8 of an inch approx 3mm?
That makes perfect sense!
Thanks
The miche primato bottom bracket is ISO taper and can be adjusted similar to the phil woods. it’s also a shitload cheaper.
I’m looking at getting a Miche ISO 109mm Square Taper as I think this will be just fine.
Trying to source one currently…
Headset issues continue but I’ve contacted Diamant in Germany and asked a lot of questions in ‘interwebz translated English > German’ 
I have one. Installed and used very briefly. Still in box.
Take your time installing this, ive found they are a very tight fit and the taper can get ‘rounded’ very easily
errr the Miche Primato Pista one is 107mm (symmetrical) … not 109mm
so depending on how tight your LH side is, you might have ‘interesting’ crank/frame interference issues. Cause each side will be 1mm close in, and if you move it over to get the right chainline, your LH crank will be 2mm in. Which may hit.
if you want to get Miche locally, ring up Hillbricks, NSW, saves on the German then 
The miche does have adjustable cups though. And who knows what spindle the Suginos were made for in the first place, 107/109/111…
I’m getting a 110 Miche Primato. The Shimano 110mm fitted perfectly so this adjustable one shold be great too.
Thanks to everyone for their help…no to fix the headset cups
Hey Gemm, How do you know the Mighty is ISO? Because the track = ISO, non-track = JIS isn’t a rule for Sugino (I thought it had more to do with NJS = ISO).
I’m quite sure my mighty’s (and matching Sugino BB) are JIS.
Edit: Gemm, they aren’t grand mightys (ISO), they are mighty compes
I remember a while ago someone linked to an article that had the exact dimensions of ISO and JIS tapers (maybe it was etomato?) but I can’t find the link or the post now. If anyone can find it, I’ll measure my mightys. I’ll measure the BB spindle anyway.
Azz, if I’ve read your posts correctly, don’t you want to go to a 104mm spindle? (You said your front chainline is 45mm on a 110 spindle, so you’d need to come in 3mm (per side) to get a 42mm chainline.
Also, Full Face, going by the sheldon link below, the frame cup outside diameter for a 1 1/8 headset is 34mm. Azz’s frame inside diameter is 30.4mm (assuming he measured it correctly which I’m not sure of given he says there is 1-1.5mm of play for ‘standard’ head sets with 30.2mm ODs. Azz do you mean .1-.2mm of play?).
I suppose it could be ‘Austrian’, though that seems a bit tight. (As b.dub said: Cup OD should be 0.1-0.25mm greater than frame ID). It might go in ok, if not, reaming the HT a little will solve the problem
Azz has vintage Sugino Mightys, not current “75” grand mightys. His 45mm chainline was on a JIS taper, unknown if symmetrical or not, it’ll be less on an ISO taper of the same length.
I have a pair of vintage 144BCD road Super Mightys, and they didn’t seat properly on JIS, but did on ISO. (and a campy 111mm put the outer ring at 42mm chainline FWIW)
And now I’m unsure if my Primato is 107 or 110mm.
Just for fun, have a look into 1980’s Suntour tapers, Superbe, VX, Suntour, how many did they need?
Frame is Greman so could have Austrian head tube sizing.
I measured it correctly. Let’s make it official that there is 1mm play using a standard 1" headset cup
I stand corrected righteously
full face
^ about the headset?
fuck I was hoping you had the answer
I was wondering the same things about chainline a few weeks ago, here’s what I found out:
Sugino Mighty track cranks were originally 151 bcd, ISO taper, as a copy of the 60s Campag model. At some point in the mid 70s they switched to 144 bcd, and also started making a JIS tapered version of the same crank. The equivalent road cranks had switched to 144 and JIS back around 1970.
I tried my 151 bcd Mightys on a JIS spindle, and being ISO they didn’t go on far enough. It was pretty obvious though - the end of the spindle barely came half way through the square tapered opening. ISO = smaller square hole.
I’ve now set them up on a 109mm ISO BB, (one of these), having seen old 109mm Sugino Track BBs. It fits ok, but there’s a fair bit of clearance - a 107mm would be better. Even 105 could be possible. That’s on my regular old steel track frame.
So if your Mighty cranks are 151 they definitely need an ISO BB. If they’re 144, double check the taper first.
Also, by the way, all the Superbe Pro cranks I’ve seen seem to fit quite nicely onto JIS spindles. Obviously it’s better to match SP with SP, but the mythical “Superbe Pro Taper” may have just been clever marketing lingo for “JIS”.