Headset collar tightening?

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,802
1,538
Checking my bike today, I found the top collar on the headset to be loose.

This is the actual heatset:

2015-07-16-059.jpg
I didn't have a big enough spanner, so I used a pair of mole grips. It's tighter than it was before, but I didn't want to apply too much torque in case I damaged the collar.

Two questions:

1) Is there a standard size for these collars, as I want to buy the correct spanner.

2) Is there a procedure to tightening the two collars correctly?
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
I always use two adjustable's, but I'm an ape.

Slacken the top one, tighten the bottom one until play is gone but bars move freely. Hold bottom one steady, nip up top one. Check, 're-adjust if necessary.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,802
1,538
I always use two adjustable's, but I'm an ape.

Slacken the top one, tighten the bottom one until play is gone but bars move freely. Hold bottom one steady, nip up top one. Check, 're-adjust if necessary.
Lovely, thanks Mike :)
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
Only snag is the bottom one is often very thin. Swan neck pliers and one adjustable might be better, but the right tools are available on EBay for £10. Search for 'headset tool'.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,802
1,538
So, if these two collars were to become loose, would there be a risk of the handlebar stem from coming out?
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon
Unlikely. It would become unridable before it fell apart.

These two nuts hold the fork steerer tube into the frame. The handle bars (connected to a quill stem) goes down inside this tube. This shows the quill stem: