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Odd threaded stem problem(10 posts)

Odd threaded stem problemDrD
Feb 5, 2002 7:55 AM
Or maybe it's not - I dunno, I just haven't noticed this before - I am installing a new stem, and as I tighten it down, the stem moves forward and touches the inside edge of the locknut - is this normal? I suppose I should move the stem around and try another spot, but I haven't had a chance to do that yet. The stem is a Syncros hinged quill with a 1" King gripnut headset and a Kestrel fork.
no problem...mickey
Feb 5, 2002 10:32 AM
A quill stem is quite likely to move when it is tightened, particularly if the mechanism is a sliding wedge type, as opposed to the expanding collet type. There is some clearance between the quill and the steering tube that permits the stem to move a noticeable amount.
so contact is ok?DrD
Feb 5, 2002 1:54 PM
So making contact with the headset lock nut is ok? (it contacts over about a cm to a cm and a half of the circumference at the front of the stem)

It certainly isn't causing the headset to bind or anything...
Contact has been madeKerry Irons
Feb 5, 2002 5:25 PM
Think about it - it would be virtually impossible to prevent the stem from touching the steerer tube/head set nut. There has to be something to keep the stem from moving left/right/front/back and that something is the top of the steerer tube and the head set nut. It can't be any other way. Therefore, it is OK.
Ok - I was just thinking...DrD
Feb 5, 2002 5:44 PM
Ok - I was thinking that since the headset wasn't binding, I was probably fine - I think it's going to mess up the front of the stem quite a bit, but hopefully not too bad! (my other stem had a wear mark/indentation on the front of it as well - however, when installed, there was space all around it (it only touched while being ridden) - taking a mic to the two stems, the new one is 5-6 thousandths thinner than the old one - also, down by the wedge, the old stem had more of a lip, while the new one looks like it was cut off a bit short. Moving the stem around in the steerer tube, I get a bit more contact when I have it installed properly, than if it is off to the side or back, but I still get a cm or so of contact - I suppose the inside edge of the steerer could be a little rounded off from the last stem, allowing this to happen...
Ok - I was just thinking...Andy M-S
Feb 6, 2002 3:40 AM
Pull the fork and take a look at the steerer. NOW! It sounds like you have a lot of flex in the steerer--particularly worrying in this case because (as I recall) the stem you are using has its wedge oriented to the SIDE.

You might have a cracked, broken, or bent steerer tube, and while riding would be a Really Bad Time to find this out.

Remove the fork and inspect it carefully, especially the point where the wedge sits in the steerer tube...
cool - something else to worry about!DrD
Feb 6, 2002 4:11 AM
I don't think the steerer tube is broken/bent, but you are right and I should probably check - I'll try and pull it this evening if I have a chance. I would really be surprised if the steerer were broken, as the fork is only a year and a half or so old and has never been crashed - I also run the stem pretty far down into the steerer (the wedge should be below the threaded region). Also - the stem seems to make contact with the locknut irrespective of the orientation in the steerer (I can rotate it to any position, and when I tighten it up, it makes contact) - also, the upper portion of the headset does not move at all while tightening things up - if the steerer were broken, I would expect to see it shift a little bit (esp. since a large portion of the threaded section of the steerer is secured with the collet in the CK gripnut headset)

The stem has a wedge in the front (I have seen Syncros quills with the wedge on the side, but all of the hinged ones have the wedge in the front)
just so you knowTroyboy
Feb 6, 2002 6:57 AM
I broke a similar stem to that, at the weld. Led to a brutal crash. I will never ride another.
cool - something else to worry about!Andy M-S
Feb 6, 2002 9:43 AM
I had an older Syncros that had the wedge on the side--you have the newer model. I've heard reports that Syncros stems are fragile...take it for what you will.

In any event, the worst that can happen if you pull the fork is that you'll get a chance to clean and lube the headset. And if there's a problem, you can find it THEN, not after loosing some skin.
an optionsecourir
Feb 10, 2002 11:15 AM
profile adapter for threaded to threadless and a threadless stem.