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Old 09-22-06, 08:36 AM   #1
corny
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Flipped Stem & Noticed Problem!

Hi to all,

I have flipped my stem in order to see if a slightly longer reach is more comfortable, and undid the four screws holding the handlebars fine. I also undid the two on the other end of the stem, holding it to the steerer, and finally the screw on the steerer to take the stem off. However, now when reinstalling it once flipped, there seems to be a gap between the FSA ring and the part below (see pic). When I tried to initially tighten the screw on the top it clicked, and now has tightened a bit further but not reduced the gap - is this normal?

The gap here leads to the bike rocking if holding the front brake on and trying to move forward.

Cheers in advance!

A slightly concerned James!
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Old 09-22-06, 08:40 AM   #2
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It sounds like you are not pre-loading the headset (this play can be felt when you hit the front brake and get tha clunk feel). I can't quite tell, but is the steering tube extending above the headset? There needs to be a gap of a few millimeters so that the cap can push down on the stem and spacer stack.
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Old 09-22-06, 08:43 AM   #3
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Hi barba, thanks for the reply.

Is the headset the end/top of the stem , and the steerer tube the part inside?

Cheers,

James
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Old 09-22-06, 08:50 AM   #4
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Hi James,

The stem is the piece that you flipped (attached to the bars). The steerer is the top of the fork (the part the stem clamps to). In order to work smoothly, the headset (the piece circled in your pic) has to have the right pressure on it so the steering will be smooth. The cap on top is used to put pressure on the stem and spacers bellow it to get the right pressure on the headset before you clamp the stem down with the bolts (after that the cap doesn't really do much). In order for the cap to do its job it needs to be able to press down directly on the stem. If the steerer is too long, all it does is press down on the steerer tube of the fork. No pressure means a loose headset and that clunk when you hit the front brake.

Parktool.com has a good repair section that will walk you through the procedure if my ramblings over coffee are not making much sense.

Cheers,
barba
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Old 09-22-06, 08:53 AM   #5
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Flipping the stem should have no effect on the required steer tube length if you're using the same amount of spacers though. I suspect incorrect tightening sequence. The top bolt has to be tightened before the clamping bolts are.
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Old 09-22-06, 08:54 AM   #6
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Originally Posted by I_bRAD
Flipping the stem should have no effect on the required steer tube length if you're using the same amount of spacers though. I suspect incorrect tightening sequence. The top bolt has to be tightened before the clamping bolts are.
Agreed, but in the pic it kind of looks like something is sticking up above the stem. OP, did you take a spacer out by any chance to get the bars lower?
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Old 09-22-06, 09:12 AM   #7
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Thanks for your help guys, the problem is incorrect tightening sequence - i did the clamp bolts first and hence the other bolt could not put pressure down. I shall correct this now and I hope I haven't caused damage!!!
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Old 09-22-06, 09:19 AM   #8
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Having corrected the tightening sequence, there were no clicks (good!) and the jerky front brake syndrome has disappeared - thankyou both for your help.

Do you think my tightening in the wrong sequence has caused damage? Secondly, how tight should the top screw be?

Cheers again,

James
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Old 09-22-06, 09:23 AM   #9
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The clicking was (hopefully) the star nut slipping in the steer tube. Probably not a problem unless it's a carbon steer tube.

You should adjust the bearing preload to allow free rotation without any play. Test this by applying the front brakes and trying to push the bike back and forth. Once it's set up, then you tighten the clamp screws.
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Old 09-22-06, 09:54 AM   #10
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Thanks, thats what I have now done. Its not overly tight, although when first loosening it, it was fairly loose! The bike used to rock a little before so steering should now be smooth - and the rocking is how I identified the problem!!

Thanks I bRAD and all other contributors!
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Old 09-22-06, 09:57 AM   #11
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Originally Posted by corny
Thanks for your help guys, the problem is incorrect tightening sequence - i did the clamp bolts first and hence the other bolt could not put pressure down.
That is a very common mistake people make. Glad you figured it out...
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Old 09-22-06, 10:00 AM   #12
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Originally Posted by The Fixer
That is a very common mistake people make. Glad you figured it out...
Yep! If you're used to quill stems, you don't realize that a threadless stem does double-duty as preload for the headset Sounds like it's all fixed now though.
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