# Overtightened Stem



## Ivy Mike (Sep 17, 2017)

Beginner's mistake. I tightened (and tightened) the compression bolt on top of the stem when my bars were moving around a lot. I know better now, and got it sorted out with the correct bolts.

I'm curious what negative effects this could have. What is likely to break or fail in the event of over tightening the top bolt? Is the frame in jeopardy, or mostly the stem and fork? I have an aluminum frame that I'd feel like a real dingus for damaging already.


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## Sideknob (Jul 14, 2005)

I assume you didn't loosen the pinch bolts on the steerer clamp before torquing the top cap / preload bolt?

I very much doubt you've done any damage apart from maybe pulling the starnut up a bit or deforming it.

Not really an uncommon occurrence and not much to worry about as long as your bars turn smoothly, there are no knocks and the stem steerer pinch bolts are tightened up.


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## RS VR6 (Mar 29, 2007)

Over tightening the top cap just usually results in the headset binding. How tight is "over tightening"?

I suggest picking up a torque wrench. This way...you'll know exactly how much you'll be tightening a bolt.


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## Battery (May 7, 2016)

You could potentially snap the bolt. 


Torque wrenches are spendy but well worth it because it could save you major headaches down the road.


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## RonSonic (Jan 8, 2005)

Ivy Mike said:


> Beginner's mistake. I tightened (and tightened) the compression bolt on top of the stem when my bars were moving around a lot. I know better now, and got it sorted out with the correct bolts.
> 
> I'm curious what negative effects this could have. What is likely to break or fail in the event of over tightening the top bolt? Is the frame in jeopardy, or mostly the stem and fork? I have an aluminum frame that I'd feel like a real dingus for damaging already.


At worst, if the stem bolts were loose, you over-tightened the headset until you got it sorted. If now that everything's adjusted properly the fork turns smoothly without binding and without excess play, you did no damage.

Less dangerously but still not right, you could have damaged the bolt in the top cap or jacked the star-fangled-nut. This is trivial both of those only serve to make adjusting the headset easy. Either is an easy fix.

Check the headset for free and smooth turning and that there is no play. If so, go ride.


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## Ken in KC (Jan 12, 2004)

Battery said:


> You could potentially snap the bolt.
> 
> Torque wrenches are spendy but well worth it because it could save you major headaches down the road.


If he snaps the bolt he referenced, he has a defective bolt. He'd pull the star nut out of the steerer tube first.


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## Ken in KC (Jan 12, 2004)

RS VR6 said:


> Over tightening the top cap just usually results in the headset binding. How tight is "over tightening"?
> 
> I suggest picking up a torque wrench. This way...you'll know exactly how much you'll be tightening a bolt.


It does? I've been riding and maintaining my own bikes for a couple years (25 or so). How would over tightening the top cap bolt bind the headset? The headset is pressed in to the head tube. The only thing the top cap bolt does is compress the headset race against the bottom headset cup.

Please educate me.

A torque wrench is a fine tool for some applications. I'd suggest this isn't one of them.


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## Ken in KC (Jan 12, 2004)

Sideknob said:


> I assume you didn't loosen the pinch bolts on the steerer clamp before torquing the top cap / preload bolt?
> 
> I very much doubt you've done any damage apart from maybe pulling the starnut up a bit or deforming it.
> 
> Not really an uncommon occurrence and not much to worry about as long as your bars turn smoothly, there are no knocks and the stem steerer pinch bolts are tightened up.


^^This^^

It's not nothing but it's really not that big a deal. The worst you'll have done is move the star nut that the bolt joins with. Adding to the the "as long as": Everything Sideknob said and as long as there's no play or movement of the fork when you jiggle your handlebars.

The worst you may have to do is push the star nut back down. A nut driver with a socket that's a smaller diameter than the steerer tube will do the trick. Put the socket on top of the star nut and lightly tap the nut driver with a hammer. Don't go too deep. Approx 1/2"-3/4" down from the top of the steerer tube and you'll be fine.

Go ride.


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