New bike handlebar independence and thightness

[silistra]

Hi, I just bought a new road bike. I tried to assemble it. And everything was alright until I realized I cannot adjust the handlebar. I tried to tighten it. One way, the other way - nothing happened. I took it out and put back the bar. Then I realized I must have damaged the rubber that stays between the handlebar and the bolt. So when I installed the handlebar back on it was moving independently of the front tire. Since I cant upload picture from my phone I'll do it later. The bike is GMC Denali road bike.

[DaveM]

It's a little hard to understand what you're doing based on your description. I'm guessing you are trying to tighten the bolt in the top of the stem in order to "tighten the handlebars". If so, that's not what that bolt does.

Watch this: http://bikeride.com/adjust-threadless-headset/
It may help you understand what does what on a modern headset, stem.

[silistra]

Yes, that's exactly what I was doing. But I wanted to adjust the height, because it was falling all the way down when I put some pressure on the handlebars.

[DaveM]

If your stem has a bolt on the top and also two bolts on the back side (facing the rider) then you have a "threadless stem". http://jail.sine.com/sheldonbrown/sheldonbrown.com/images/headset-threadless.jpg

If it just has the single top bolt, then you have a "threaded" or "quill" stem. Depending on which model bike you have, you could have either type of stem. But you have to know which it is as the procedure is completely different.

I was assuming you have threadless because you mentioned the "rubber that stays between the handlebar and the bolt". Try to post pictures if you can or at least be a lot more detailed in your description. But be careful, obviously it is important this doesn't slip or it could cause a crash.

[GeorgeET]

Googling up GMC Denali:

http://www.target.com/p/gmc-men-s-denali-700c-28-road-bike-yellow/-/A-11894039?ref=tgt_adv_XSG10001&AFID=Google_PLA_df&LNM=%7C11894039&CPNG=Sports&kpid=11894039&LID=PA&ci_src=17588969&ci_sku=11894039

This is not a threadles headset.

http://sheldonbrown.com/gloss_st-z.html#stem

Scroll down to stem. If you cannot tighten it clockwise with the top bolt, most likely you have a a wedge, and sounds like you unscrewed it and it dropped down into the head tube. Try turning the bike upside down and see if it comes out, look from bottom too. Otherwise you will need to get the top head nuts off and than retrieve it.