Headset not screwing onto forks correctly

I'm trying to install a new headset, using a 1inch ultera threaded headset. It fits but then when i screw it on i get about 1/2 an inch onto the fork it seizes up and i cannot tighten anymore. i'm using a large park tool wrench so i'm getting more than enough torgue on it but it won't keep going. I've tired:

1. undoing it and cleaning the thread
   
2. putting it in the freezer (thought it might shrink metal)
   
3. force
   
   

should i invest in a real headset wrench or is there another solution / issues that i'm missing?

any help much appreciated.

Is it a different model headset to the one you're replacing? And are they the same forks?

i've changed the forks as the ones originally on it are too short for the new headset the new ones are the same width just longer. does this matter?

i've changed the forks as the ones originally on it are too short for the new headset the new ones are the same width just longer. does this matter?

in addition to above the headset is also different as i'm doing a retrofit on an old Charlton frame.

Is it possible that the fork is too long at the moment? The headset topnut can only wind down so far

maybe but the bolt fits really well for about 1/2 an inch - is this as far as it would go?

if so looks like i'll be moving this post to the trading area!

This is what I'm getting at:

If the lip is hitting the top of the steerer you need to trim the steerer.
Presuming I'm understanding what you're saying that is.

Which bit are you trying to fit? The upper race or the locknut?

Which bit are you trying to fit? The upper race or the locknut?

the upper race or ' upper head cone housing'

nope i saw that image on park tool's site (or sheldon brown) but it doesn't have a lip to catch and seems that the thread is getting wider on the stem (it is already well past the lip before it seizes and you can still crew but it needs loads of force.

Ooooh I see, it's the upper race not the topnut. Ignore all I've said. I reckon a dose of HTFU should sort it in that case.

The fork definitely has English threading, yes?

Definetely both 24 TPI? If the forks are genuine Carlton they may be 26 TPI, depending on their age

The fork definitely has English threading, yes?

How old is the Carlton frame? Raleigh had their own type of threading back in the day...

I've fitted the same piece on a old raliegh fork and a antoher charlton fork (both incorrect steering length) and the piece seems fine.

The difficult really is after 1/2 inch onto the steering (before that the part fits perfectly) - it seems to get wider????

Definetely both 24 TPI? If the forks are genuine Carlton they may be 26 TPI, depending on their age

sorry what does TPI stand do?
and yes definitely english treading.

Ooooh I see, it's the upper race not the topnut. Ignore all I've said. I reckon a dose of HTFU should sort it in that case.

posting 3 times in a row - but does this reply mean that i should buy the right tool and just apply more force????

you shouldn't need to apply a lot of force if the upper race is not yet near the bearings (in fact you shouldn't need to apply force even if it was as this would overload the bearing). Options include:
1) The thread on the forks is different to thread of the upper race
2) Thread on fork not clean or obstructed by swarf/rust/crap

If the old headset top race goes on/off without excess force (still - try it now) then it would suggest no.1. If the old top race gets stuck now it would suggest no.2.

Excess force should not be required, and indeed is likely to permanently damage an Ultegra top race since it is alloy.

cheers for that - yep, i've been worried about damaging the alloy. hence thinking about buying the 'proper' tool but i'm getting enough force therefore threaded down the fork must change or the thread up the fork has been mangled in the past hence fitting fo tht efirst bit. i'll source a new fork.

Yeah, to be more specific, if the threads on the fork are good and you have greased them, the nut should go all the way down to the bearings without any need for tools - something's up somewhere!

Like R-d-C says really - as it's alloy go easy on the HTFUing ;-)
If the thread is damaged in any way it'll be obvious to the naked eye.
I've actually got a set of forks at home where the steerer has been extended and this presents a similar problem, as obviously it is fairly tricky to extend a bit of threaded tubing correctly - might be worth checking that this isn't the case here...

Oh and TPI is threads per inch - bearing in mind an inch is 25.4 mm you're looking at a little bit above or below 1mm between 'peaks' on the thread depending on your threading type

Like R-d-C says really - as it's alloy go easy on the HTFUing ;-)

Oh and TPI is threads per inch - bearing in mind an inch is 25.4 mm you're looking at a little bit above or below 1mm between 'peaks' on the thread depending on your threading type

TPI is indeed threads per inch, I don't understand the second part of this sentence.
1" forks relates to the diameter of the steerer not to the TPI

Well without getting too technically - if you measure between two peaks on a thread and it's just under a mil then you could hazard a guess at it being 26TPi, or if it's just over a mil, 24TPI - the 1 inch bit wasn't a reference to diameter more just a confusing method of working out how TPI you're dealing with on a fork thread. Works for me, but I seem to like doing things the hard way for some reason...

^^ Ah yes, I understand now. Sorry I'm a bit tired and consequently, slow.

Likewise, burning the candle at both ends at the moment...

The difficult really is after 1/2 inch onto the steering (before that the part fits perfectly) - it seems to get wider????

Sounds like someone has overtightened a stem into the fork, and caused a buldge in the fork steer.

If that is the case, it trash basically. New forks, or get then steering tube swapped out by a frame builder.