Have been collecting parts and doing measurements for this for a while and having taken the first steps to fit a new set up (a tapered fork to a frame for an internal 1+1/8 headset/non-tapered fork) I was foiled at the first step! Pressing the new headset cup in it stopped going about 1mm before snugging up with bottom of headtube. What to do? Creatively ‘shorten’ the inner sleeve of the new cup? deal with the 1mm gap? or try and source another cup?

The frame is a voodoo bakor, and yes, I have considered fork length and geometry.

Why not just leave the normal top headset in as it will fit the straight bit of steerer? Or is the taper too long for the headtube?

I am guessing you are fitting an external lower cup to push the wider bit down?

Hiya, I didn’t describe it right. the lower cup fits in to the headtube but not all the way leaving some of the inner bit, what I called the sleave, of the cup exposed at the bottom of the headtube.Basically this

http://singletrackworld.com/forum/topic/voodoo-bizango-owners-headset-advice

in fact, mebe I am wasting your time given this already exists as a thng on stw. Then again, might try the lathe option.

This happened on my brothers carrera fury. He just left it with a 2mm or so gap

Ahh sorry was thinking top cut for some reason.

If there is any material to trim off the cup I would so do, otherwise there is not a lot you can do. You could look for something to use as a shim like a bottom bracket spacer (but 44mm ID not 35), although if you split a BB spacer and put the split round the back it will fill the gap.

I would really advise trimming the headset down over a spacer though as it will raise your A-C and increase the bending moment on the base of the headtube.

Edit: all at your own risk of course.

there is an engineering lathe at work. apparently they are going to let me use it tomorrow morning, what could go wrong?!

You could leave it and it wouldn’t be a problem, or cut it down with a hacksaw which is what I did with mine. I am pretty good with tools though so it was straight and even!

I would really advise trimming the headset down over a spacer though as it will raise your A-C and increase the bending moment on the base of the headtube.

It’s 1mm. It will make bugger all difference.

but without the headset butting up to the base of the head tube it’s not as stable and he is already extending the moment arm compared to an internal bearing. It’s just not a nice solution, what he is doing with trimming the cup is much nicer.

AC wont change cos that’s in the fork, what will change though is axle to bottom of headtube, which will already be extended by the fact there is an external cup rather than an internal cup.
Take the excess of the bottom cup

I’d slice just over 1mm off in the lathe. pretty easy to do but if you aren’t handy on the lathe you do risk damaging it. Key will be getting it held right in the chuck. To tight or too loose and you’ll knacker it. Less risky way would be be to lay some wet and dry on the bench then rub the headset on it, checking regularly to make sure you are taking off an even amount.

lathe-ing worked great. decided to take more than 1mm off, turned out i had plenty of material to play with. sits in frame now ready for fork.