no, you have to just inspect the bars with a point caliper, if at all possible.

they're probably fine, but just as a rule of thumb- if there's a problem on a bike, the LAST thing you want to do is "tighten bolts more." that's pretty much universal, unless something is coming loose.

the headset thing... well... if you were REALLY putting a lot of force on the cap bolt, you'd at very least pit the bearing races in the headset, if not pull the star nut out, if not worse. and in all likelihood, the bearing races in your 'aheadset' are just going to be slightly pitted so it will wear out super quickly.

then again, the 'aheadset by cane creek' headsets (usually an aheadset sts or similar) are crap headset anyway and probably wouldn't last long anyway... you basically are in a position where you can either - ride it with a pitted race until it stops rotating freely or becomes so unpredictable in its bearing friction that you don't want to ride it anymore or - just buy a new headset that is of good enough quality where you'll actually want to learn how to install it and adjust it before tightening any bolts.

the thing to rejoice in here is that you learned two, if not three, very important lessons...

1. measure twice, cut once...

or in this case, be absolutely sure everything fits together and is the right specification for what you want to use it for before you go installing or adjusting or using it, especially with other parts. had you taken the time to measure the stem and bars to make sure they fit together, you wouldn't have had a problem. not talking down to you, just trying to be clear that no matter what it is... you should always verify that things are right before you go and use / cut / install things.

2. screwing stuff can screw it up.

torque is a very important part of assembly. certain materials will break and you'll strip the threads off of stuff very easily if you don't pay attention to what the part calls for. you don't need to take a torque wrench to every bolt every time you adjust anything on a bike, but it doesn't hurt and simply tightening stuff is hardly ever the right answer to a problem that isn't fixed by hand tightening. thank god you don't adjust derailleurs.

3. (kinda the same as one, but let's extrapolate a little...)
Knowledge is key.

If you don't know what you're doing... don't do it. Even if you think you know what you're doing... like adjusting a headset... it's always best to check yourself before you wreck yourself. If you knew that bars came in slightly different diameters, you probably would have thought to check before you used the stem and discovered the ticking problem. It's basically the thought/philosophical application of measure twice cut once.

On the bright side... you're not hurt, your bike can be fixed, and nothing really actually broke.


A lot of people think that 25.4 and 26.0 bars are so close in diameter that you can use them interchangeably... and they're not wrong in all cases. but they're wrong in this case, and i'm hoping you didn't damage those bars(nittos are expensive for a reason... they're nice) trying to make that stem(which looks nice, but i didn't think was all that hot) fit.

another upside is that a lesser stem, or a lighter stem of higher degree of design and engineering... would have sheered on the threads if you really wrenched on the bar bolts. makes me think they overengineer the VO stem, at an expense of weight, to be really strong and fool-proof. i've had two stems strip on me, and they weren't even all that nice... easton ea30's strip easier than a drunk guy at a bachellorette party.