jambon

Hi ,

As in the title , I changed out a stem on a bike with a threadless headset . But after doing so the headset wont tighten up . I assume the new stem is slightly shorter than the old one and so the total height of spacers and stem combined has decreased .I tighten the cap bolt as much as I can but still the spacers are not pressurised and can jiggle about freely .

Will putting a 3mm spacer in there sort this out ? I say 3mm as that is the smallest I can seem to come across wirth an online search .

Thanks for any help ,

J

evan326

You didn't tighten the stem all the way first did you?
I've gotten 1 1/8 spacers as small as 2mm, pretty sure I've seen as small as .5mm

MikeOK

Your steer tube should be slightly shorter than the top of your stack of spacers. Like maybe 1/8". You don't need that cap to be super tight, just tight enough to take the slack out. What you want tight is the pinch bolts on the stem, that's what actually holds everything together.

corrado33

None of us will be able to tell if a 3mm spacer will work because we can't see the bike.

But you definitely NEED a spacer, of some kind. And the top cap bolt does NOT get tightened all of the way, just enough to preload the bearings.

fietsbob

If the stem is flush with the top edge of the steerer tube, the top pre load cap cannot work as designed.

then you must put a spacer above it... stem bolts loose, around the steerer, until after the headset is right.




...

jambon

Yes thats the problem .

I have the stem at the bottom (40mm) then the two spacers above it (10mm) each . The top spacer is flush with the steerer so the pre load cap is not working . I was thinking a 3mm spacer but will this work sitting unsupported by any steerer tube on top of the 10mm stem below it ? Would not a better move be to remove the top 10mm spacer and pop in a 13mm or 12mm spacer if such a thing exists ?

corrado33

Remove a 10 mm spacer, place 3mm spacer under, replace 10mm spacer, replace top cap.

djb

Isn't it possible that from overtightening the top bolt that he has borked the starnut?

Don in Austin

I once bought a fork at swap meet and wanted to put it on my bike to ride home. (threadless) I didn't have enough spacer thickness for the length of the fork so I recruited somebody to put all their weight on the bars and stem, tightened it and rode home. It steered fine, but I did get another spacer.

Don in Austin