Quill Stem Question
 

Hi All, I've just had my third stem that the handle bar clamp didn't release the handle bar enough to seperate the two without resorting to forcing the clamping area apart. My guess is that the bars and stem have been attached for at least 15 years. The first two were Nitto stems and the third is a copy of the Nitto made by UIM(?) in Japan. I tested a fourth UIM stem that wasn't clamped to a handle bar and it accepts a handle bar normally.

Is this fairly common?

TIA, Brad

I never owned all the Nittos ever made but I do have a Technomic stem and that one had no issue releasing the bar, nor have I had with any bar/stem. If you're having to pry apart the clamping area then someone may have either way over tightened the clamp, or the bar was too big for the clamp and the previous owner pried the stem apart to but it on.

rekmeyata, The handle bars that I removed showed no sign of being forced into the stem, but certainly a PO may've somehow installed an oversized handle bar. I just never came across this in past years and then these three in the last six months or so and I'm just curious if anyone had the same experience.

Brad

Short of being corroded into place (which I have never seen but it is possible), or the size of the bar was incorrect as discussed earlier, there is no reason someone would have to pry the stem apart to get it to release the bar. In fact if the right size bar is used the bar should slide freely inside the clamping area of the bar even at the bends (though at the bends you do need to turn the bars a bit to get it past the bend.

Prying on a aluminum clamp that wasn't designed to be bent could result in a cracked stem clamp, so extreme caution needs to be taken when attempting such a move. If the stem is going to be replaced then no big deal if the old one cracks. The best way to open the clamp if you need a bit of space instead of using a screwdriver is to unscrew the clamp bolt and insert a penny into the slot, then tighten the bolt against the penny, this will open the clamp a bit, but don't open more than what it will take to make the bar slide. Leave the clamped penny installed while removing the bar. You can do the same thing when reinstalling either with a new stem or a new bar.

You could also a quarter, BUT, if the aluminum clamp is of the thick variety it could crack it, so do so but only at your risk. It shouldn't have to open more than 0.5mm, any more than that it you risk damaging the clamp.

There are some designed stems that the penny trick will not work, so it depends on the stem you have.

Also you can use hand soap to help the bar to slide easier once it's loose.

Even with that bit of space scratching the bar will occur, however only around the bends of the bar which tape will cover anyways.

Consider the coin method of inserting and removing bars. It's relatively easy and summarized by Jan Heine here. Tight bar and stem combinations are common.

Reads like there might have been an over torqued bar binder bolt.
If after spreading the stem a bit and moving the bars to the side enough, if the bar is deformed to any extent there is your answer.

Just ran in to a similar problem, bought a bike and the Cinelli 1R stem was missing its wedge bolt, and the bars are tight. Going to have to decide on what to do there.

Don't like stuck bars...

But hate loose bars more...

Nothing gave the appearance of being over tightened, based on the handle bar after removal and none of the three pinch bolts felt overly tightened. I used a hardened washer to seat against the pinch bolt to loosen the clamp, no more than a 2/3 turn at most on the worst of the three was required.

I think the corrosion theory might be the most likely and with one I discovered last night could've also been a small piece of dislodged casting flash. After cleaning the inside of that one and filing away the remaining flashing I reused that one and it took about a 1/4 turn of the pinch bolt to install the new handle bar.

Brad

They just like each other, perhaps. I've often had to insert a screwdriver, turn it sideway, and lodge it there in order to get a bar "cleanly" out of the clamp. So often, that I consider it normal.

I've had that happen, but only if someone's worked a 26.0 bar into a 25.4 clamp (not that uncommon a situation), or if it's simply been oxidized onto place; in which case soaking it in household ammonia for a day or two does help to break down some of the oxidation. That, and a lot of Liquid Wrench.

The 'penny' method is the one I've used (and it's usually worked), but If you try the 'sideways screwdriver' method, be very careful in applying torque and rotating the driver blade: cast aluminum can snap.