Headset keeps loosening

[nathanm26]

Hi,

the headset on my dynatech keeps loosening. I have tightened the lower nut, and then tightened the upper nut onto the lower nut, but both keep loosening when out on the bike. I keep having to tighten both by hand intermittently during a ride. Its become second nature now but I'd rather sort it out.

(I'm referring to the 2 nuts that thread on to the steerer)

This evening I tightened the lower nut until the headset bearings almost felt crunchy and then tightened the upper nut as much as I thought was sensible with a big wrench, but it still happened after 3 miles.

Any ideas????

N

 

[Robbied196]

That's a bit of a strange one.

It could be worth checking the cups in the headtube are tight, if they are loose its possible they could work the locknut loose.

Do you have loose bearings or caged? Worth a check if they are caged that they both face outwards from the headtube, although even if they are the wrong way around it would be unusual to loosen the locknut.

Sometimes there's a keyed spacer between the top cone and the locknut. That allows the locknut to tighten without adding pressure to the cone, I'm not sure whether a dynatech has one or not but could also be worth a check.

You also don't want the cones to tight, they should just touch the bearings. A good check is to apply the front brake and push down on the forks rocking backwards and forwards. If there's no play and the forks turn smoothly then the adjustment is right.

 

[lewisfoto]

as much as I thought was sensible

That is a tough one to figure out sometimes. I had the same problem with my Colnago for a while but was able to get it sorted out.

If I had to guess it would be that you are not putting enough torque on the top nut.

 

[Midlife]

Is there a spacer between the two? If there isn't there can be trouble.....

http://i41.tinypic.com/4er6o.jpg

Shaun

 

[joe careless]

sounds like your bearings are worn/damaged. use a biro to feel the faces of the head set cups for any defects and replace the bearings. caged bearings are an enathema, slightly worn and they start screwing the facings imho

 

[keithglos]

My experience is somewhat older, but we always used 2 spanners and tightened one against the other. The tabbed or flatted washer does help.

 

[glpinxit]

Worth checking you have the correct size balls in the top race (guess how I know).

 

[nathanm26]

Hi all, and thanks for the replies.

Yes bearings are caged. I do the rocking test when it's tightened Robbied, and when it loosens out on the road you can imagine what it feels like!
Yes Shaun I think I recall a spacer between the two when I was putting the headset back together but will double check. I think I will do a bit of examining this evening (will also take a look at the headset cups as you suggest joe), take a few pictures and report back. As Keith and Lewis suggest, maybe to do with not being tight enough, but I certainly felt like I couldn't have taken it much tighter.

N

 

[Woz]

My experience is somewhat older, but we always used 2 spanners and tightened one against the other. The tabbed or flatted washer does help.

This. I had the same problem once. Check that the threads are good to begin with and not worn, and try cleaning off any excess grease from the top lock-nut too.

 

[hamster]

A better way to tighten:
1 Do up bottom nut .
2 Tighten down top nut
3 Holding the top nut with the spanner, loosen the bottom with a second spanner - this tightens the two against each other. I reckon an inch or two of movement of the bottom spanner end in my hand usually (so around 1/8 to 1/16 of a turn).