Bicycle Mechanics - headset adjustment

Hi
I have a jdx stronglight headset and it was beginning to bind a little and i found i could unscrew the top part with my hand.I have greased it but how do i torque it.I am used to
a locknut but this came apart in one piece.It looks like two pieces with a plastic slip ring.
as usual any info much appreciated

Does your headset look like this?

http://velobase.com/CompImages/Headsets/D924F364-B1E2-4FF3-9168-019FF1B885F4.jpeg

http://velobase.com/ViewComponent.aspx?ID=6FC753AD-1486-4AAE-82C0-C9FF3B7A3C17&Enum=111&AbsPos=6

I think there is a special tool that gors in the "slots" but also if you carefully remove the black ring, very carefully don't break it, there is likely to be a allen bolt to tighten it after adjusting it.

That Stronglight headset does not really have a locknut as we normally know it. It uses a Delrin (that black plastic portion on the top nut) insert within the top nut to act like a "nylock" nut against the threads and not loosen. If you were able to remove that top nut with you hands, it might be that the Delrin insert had worn to the point that it is not providing enough friction to retain it to the steering tube threads....it's most likely worn out and needs replacement. Never really liked this design by Sronglight, but I guess they expected it to work well and long enough.........BTW, JPR used the same lock nut system on their headsets. I have both headsets (NOS) in my stash. and I'm reluctant to use them on any future bike project because I question how well the top nut will be retained on the bike by the Delrin. One thing I'm kinda sure of, is you shouldn't really remove and reinstall these headsets too much after you first install them as the Delrin part WILL eventually loose it's ability to properly retain the nut to the steering tube.

Chombi

One thing I'm kinda sure of, is you shouldn't really remove and reinstall these headsets too much after you first install them as the Delrin part WILL eventually loose it's ability to properly retain the nut to the steering tube.


Well that seems kinda stupid...

OP, I hope your headset isn't worn out. Good luck.

Well that seems kinda stupid...

OP, I hope your headset isn't worn out. Good luck.

Hey man!, it IS French!:D

Chombi

That Stronglight headset does not really have a locknut as we normally know it. It uses a Delrin (that black plastic portion on the top nut) insert within the top nut to act like a "nylock" nut against the threads and not loosen. If you were able to remove that top nut with you hands, it might be that the Delrin insert had worn to the point that it is not providing enough friction to retain it to the steering tube threads....it's most likely worn out and needs replacement. Never really liked this design by Sronglight, but I guess they expected it to work well and long enough.........BTW, JPR used the same lock nut system on their headsets. I have both headsets (NOS) in my stash. and I'm reluctant to use them on any future bike project because I question how well the top nut will be retained on the bike by the Delrin. One thing I'm kinda sure of, is you shouldn't really remove and reinstall these headsets too much after you first install them as the Delrin part WILL eventually loose it's ability to properly retain the nut to the steering tube.

Chombi

Really? how interesting. Since all I had to go on was the pic from VeloBase I thought it was like the later Mavic HS

Really? how interesting. Since all I had to go on was the pic from VeloBase I thought it was like the later Mavic HS
Yup, that whole top nut is pretty much one piece There is no separate jam nut. Notice that there are no threads on the top aluminum portion of the thing. I think the black Delrin portion was moulded right into the top nut. It sure does not come apart for me.....

Chombi

I forgot to ask the OP,....
did you also check if the steering tube is long enough that you get full engagement with most or all of the treads in the delrin portion of the top nut before the bearings bottom out? This headset is sensitve to steering tube/threading legnth, and if you are only engaging a minimal amount of the Delrin bushing, it will not stay on the steering tube and will unscrew too easily as wyou will not get enough locking effect from the top nut. I think I have mounting instructions for the headset and IIRC, there is information in it on how long the steering tube has to be. I will try post a pic of it for you as soon as I can.

Chombi

Thanks everybody that picture from bianchigirll was very useful.Judging from experience i would say there is about 300in/pds of torque on it.
I rode 50 miles today on rough roads and it stayed true.It's a 98 bike that was never ridden so maybe the binding was the old grease and me parking it beside the hot radiator at home, who knows.
Cheers

So, maybe the top nut was never screwed on all the way as it was an NOS bike.......thus you could take it off using only your hands........unless you have really strong hands?
Glad to hear it worked out then..

Chombi