Have some 2nd hand SIDs; lovely condition and only v light use. They're replacing my Pace forks.

However, it seems impossible to get the crown race squarely seated in the headset, so the forks won't sit square (so they end up rubbing on the top headset) and when tightened, grind. They look as though they sit higher at the back of the crown race.

This is still the case if I rotate the forks 180 degrees (and they rub at the same point and still look high at the back of the crown race) so it's not a bent steerer. I've tried 2 different headsets. Alternative forks fit fine and dandy. The LBS is mystified. The SIDs ran fine on the one previous bike they were on according to the owner.

Any suggestions of what to look at – much rather keep them than return them.

Ta

you are changing the crown race on the fork for each headset aren't you? Crown races differ between headsets (even fromt he same company).

that should sort you out?

If the crown race is seated properly, then something must be bent or misshapen.

Firstly you are using the same crown race that you had in your last forks?

If so, perhaps you bent it when you removed it?

Yep – using the respective crown race with each headset.

Certainly the race doesn't look bent, and my Pace forks refit perfectly square.

Plus the 'gap' always seems to be at the bottom of the headtube between the race and the headset and at the rear of the headtube. This remains the case if I rotate the forks 180 degrees so if the race was misshapen, then I'd imagine the 'gap' to move too?

What else could be bent / misshapen???

If the steerer / crown race / top race was a slightly smaller diameter or not compressed into position properly the steerer wouldn't be sitting perfectly square in the bearings.
The angle of the head tube/forks would then cause a gap to open up at the bottom and at the back (and also at the top and front, although this may not be as obvious)…..

Do you have the top race fitted properly?

glenh – makes sense. I 'think' all's correctly in position.

Certainly, if I pop the race onto other forks (with no adjustment to the installed headset) then other forks fit fine. I've carefully tried to ensure the crown race is firmly and cleanly seated

have you tried the SIDS in another frame?

tbh does sound like it's the SIDS having 'issues' – have you put a straight edge down the steerer?

Are the bearings the right way around i.e.

what headset have you got ?

Sometimes top and bottom bearings are different sizes? But this doesn't really explain the rubbing when twisting?

Is the crown race sitting level?

This is still the case if I rotate the forks 180 degrees (and they rub at the same point and still look high at the back of the crown race) so it's not a bent steerer.

[/b]

Plus the 'gap' always seems to be at the bottom of the headtube between the race and the headset and at the rear of the headtube. This remains the case if I rotate the forks 180 degrees so if the race was misshapen, then I'd imagine the 'gap' to move too?

I'm confused – or stupid – which is it?

Aus,

YGM re Canon G9

Oh, and good luck with your forks/headset! :0)

BB

cynic-al – my poor writing! Once the forks are installed, it looks as if there is a v small gap between the race and the bearings at the rear of the headset.

If I take the forks out and re-install back to front (ie. the forks spun 180 degrees), the gap is in the same place.