how tight does a threaded stem need to be?
 

My stem seems lose? I've tightened it down now pretty good, but when I put the wheel between my feet I can still turn the stem with some force? Is this normal? I don't believe the stem is inserted enough to be into the butted part of the head tube? so what gives?

It should be solid when you've torqued it to around 8 to 10 foot lbs.

and since it's not....what does this mean??

Overtightening a threaded style stem isn't good. It can forme a bulge in your steerer tube which can be a big problem down the road.

As long as your stem doesn't move side-to-side during normal use, that's tight enough.

threaded? threadless?

I go by the rule-of-thumb method. If I can turn the stem in steerer it is not tight enough. Its also important not to tighten it too much. You want your stem to turn inside the steerer in case of a collision. A collision causes a lot more force than just your hands can handle. bottom line is, that your not tight enough.

So since its still turning, I assume it's not tight enough? but would it be possible to create a bulge in the steerer tube while it can still move overly easily??

oh and threaded

Not likely, unless you got some very thin steel making up your steerer tube. What I do, and have done many times on quill, wedge threaded stems is

1)make sure the steerer tube is free of junk on the inside.
2) thin coat of grease on the wedge .
3) insert, align, tighten down with an L shaped allen wrench until its snug.
4) test the grip the wedge has on the tube by holding the wheel between my legs and turning the handle bars.
5) if the stem rotates, I'll re-adjust and keep tightening until I can't move it in that position.

this method has worked fine on all but one of my bikes, many of friends families bikes, and the occasional one I sell.

save the torque wrenches for the carbon fiber!

i've pretty much tightened it as much as possible with the L allen wrench on its own, (and I'm not a weak guy) and it's still moving....but it's a short lever? so what do you think, should I go crazy on the little lever I've got and figure I'm not getting too tight? and hope that it snugs up?

Nope, pull it out and check out what's going on. There is no way at all that a good pull on the allen key handle will not lock a properly functioning stem solidly.

Check out the stem down by the wedge for signs of trouble. Ensure that the wedge is able to slide along the angled interface easily and without catching. Esepcially make sure it can slide along the face enough that the upper pointed end of the wedge clearly moves past flush with the upper part of the stem. Tighten the bolt to do this so you're sure the threading is long enough to suck the wedge fully up past flush so you KNOW that the wedge will properly lock the stem and that the threads on the bolt are able to pull it that far easily.

I'm sort of guessing that your stem bolt may have been replaced at some time or the thread is damaged and it is not able to screw freely into the wedge far enough to properly lock the stem in place. Either that or there's something interferring with the wedge being able to slide along the angled face far enough to fully lock the stem in place.

If the stem checks out then I'd suggest undoing the headset and drop the fork out the bottom for a looksee. Check for bulges or signs of splitting or other deformities. If you have a set of calipers check it for roundness and eveness of the outer diameter along it's length in spots with particular attention to where the wedge would be sitting. If the stem is all good then there's a good chance that there's something going on inside the steering head that will likely scare you out of a year's worth of life.

Alright, so.... I pulled the stem out and inspected it. I couldn't see that there was anything wrong (plus the stem and bike are essentially new... although not of the highest quality). So I pulled out the fork and again everything seemed to be normal, but I do not have a set of calipers to check to see for eveness/roundness. Put it all back, and still the same deal. I doubt that it would come lose during riding, but perhaps on and bump turning or some such out of the ordinary its a bit scary.<br>
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So...any other ideas? I'm a do it yourself type, and I hate to take it in, but at this point it seems to be either that or just ride it as is?

The stem bolt will easily pull the stem wedge up past flush so the top of the wedge is sticking out?

If so what about the wedge? All of mine on the forged stems have steel wedges that have vertical small ridges on the outer surface so they tend to dig into the inside of the steerer. Does your wedge have those as well?

Any time I've ever adjusted my bars to straighten them I have to undo the wedge quite a bit to let the bars move. If I snug it just a hair too much to sort of lightly hold it from falling down then I feel like my front wheel will taco from the side force before the bars will move. And that's from a LIGHT sort of pinch on the allen key. Once I bear down on the allen key they may as well be welded in place for all that they are able to move from me forcing them.

Any chance of a picture of the wedge and lower stem?

here are some pictures.

Well that clears all that up. I honestly don't know what to say. Your stem is so doggone similar to all of my oldies that they could be the same thing.

As I posted last time if I snug them up a hair too much when trying to just pinch them so they can be aligned with the front wheel I need to ease them off because they grab like a cat climbing a set of drapes. Once I reef them down they may as well be welded in place.

Yet you say you can grab them and turn them in the steer tube. Amazing..... Is this stem the right size for the steer tube? As in does it fit down in the tube with almost no perceptable slop side to side? It should fit well enough that you can't imagine slipping so much as a little sliver of writing paper in along with the stem. If it's much looser than that I think there's a sizing issue at work.

In any even if the stem can be moved as in your case the stem will not stay where it is supposed to stay. It may not swing around and make you crash but it'll work itself up or down in the steer tube depending on if you're lifting on it going up hills or leaning on it more than you're lifting. But sure as shootin' it will wiggle its way up or down and probably alter the angle slightly as it does so.

I'm stumped from this end whithout being able to see the situation in person I'm afraid. I'm sure there's SOMETHING that would jump out when the guy looking at it knows what to look for but it's hard to figure out long distance like this. If the stem is a non sloppy fit in the steer tube as mentioned above I can only suggest take it to a different LBS where they have someone that remembers what the old threaded stem issues were "way back when".

Best of luck with this thing.

One last item. I can't imagine this making a difference but I slather on grease over the whole thing. On the bolt threads, under the head where it turns against the upper cap, on the slopes of the wedge and on the wedge and lower stem itself. I then gloop the stem down into the steer tube and tighten the bolt with a regular length allen wrench and just a good twist without popping a blood vessel or severley nerve damaging my fingers. I don't know if all the grease helps things slip and lock but it may be worth a try.

Sorry I can't be more help and get you safely on the road again.

OK, one last "one last" thought. Use a fine cut metal file or an oil stone to polish up the sloped face of the jam wedge. If it's overly rough it may be digging into the alloy upper part and not sliding as easily as it should..... yes this IS a shot in the dark and my last grasp at the straw.

Thanks, I appreciate all the help. When I slide the stem in without tightening up the bolt there is a bit of play front to back, very little side to side, but it's not as tight as it could be. This is interesting because the stem and fork were sold together as a new complete bike...so it'd have to be a machining issue then? I'll take it in and see what they think. Thanks a lot though!!