Bicycle Mechanics - Threaded headset adjustment - before I start.....

... a couple of quick questions.
My recently aquired (last night) MBK Amateur has a 1" threaded headset that is ´sticky´at the straight ahead position i.e. it doesn´t want to turn away from straight on.

Am I right in thinking that the headset is likely to be overtightened? It´s Shimano 105.

Would the Park Tool headset adjustment viideo be a good place to look before I start unscrewing stuff?

I thought I would break with tradition and actually ask for advice before I start wrenching on a bit of the bike.

Thanks in advance!

Simon

Explain more.
Is the stem stuck inside the head-tube. This is not a headset issue at all.
Is the locknut stuck on the headset.

... My ..has a 1" threaded headset that is ´sticky´at the straight ahead position i.e. it doesn´t want to turn away from straight on.
This usually means that for one reason or another the bearing races have become dimpled, and when the balls line up with the dimple[s] it acts as a detent. Backing off on the bearing preload might make the issue less noticeable, but is unlikely to make it go away. Going from caged balls to loose balls is another popular way of trying to prolong life in damaged headsets, the idea being to break up the alignment between dimples and balls.


..Am I right in thinking that the headset is likely to be overtightened?

Probably not, or only partially, depends on how bad its sticking. In a perfect world an overtightened headset would simply be smoothly resistant to turning whatever angle the wheel is pointing at.


Would the Park Tool headset adjustment viideo be a good place to look before I start unscrewing stuff?

Depends on you mechanical skills. If you're concerned enough to ask it's probably a good idea.

would like to know too

Seychelle Gabriel (http://seychellegabrielfan.com/)
Watch Tron Legacy Online (http://watch-tron-legacy-online.com/)

I found this (http://www.atomiczombie.com/ct-headtube.html#headtube) website very helpful when I first took apart a headset.

yes i need more details

Right chaps, thanks all for the replies.

The stem is not stuck in the head tube, although it did require a light tap on the top to release it.

The stem has been tightened up again and the problem is still there.

I am inclined to go with the dimple theory.

I will let you know how things go. It´s a shame because the rest of the bike was more or less ready to ride from the get-go, I just don´t feel confident about taking it through traffic with this steering issue.

It's not an adjustment issue. Have the headset replaced.

dabac is correct. Another option is to remove the cups, and reinstall them so that the dimples don't line up together any more. A new headset is ideal, but not necessary depending on how picky you are.

OK, to the shop it is :-(

Thanks all for the advice.

If it's dimpled, then it may turn freely, but it will sort of "click" into place in the straight ahead position, and take a tiny nudge to turn one way or the other. If it's tight to turn no matter the position, then it could just be an adjustment issue .... too tight.