1" Steerer- worn threads

[Halla]

Good Morning all.

The threads on the1" steerer of my old touring bike have worn and the headset now will not stay correctly adjusted.

I have secured it with blue/medium thread lock, but not tested the repair by riding the bike yet.

Should the thread lock be considered a permanent repair or should I seek a better solution?

I posted some months ago about raising the handlebars and could now combine both modifications together.

Can steerer extenders/raisers be used to secure the headset and raise the bars whilst converting to an ahead-set type stem?

The headset is a Stronglight A9 with needle bearings, not sure if will make a difference.

The solution needs to be cheapish and easy as the bike is now only used during the winter for rides up to about 30 miles.

Thanks for your help.

Andy

[rjb]

If the headset is an aluminium A9 it may be wear on the alloy threads not the steel steerer. Try wrapping a few turns of PTFE tape around the threaded steerer to see if you can improve the fit.
Ps poke your right thumb in the top of the steerer and your fingers then show the wrapping direction for the PTFE tape.

BBB made an aheadset converter for threaded steerers but you would need to use an aheadset top race and coller.
viewtopic.php?t=154091#p1740178
viewtopic.php?t=133591

[KM2]

You can use an extender system. As used on Airnimal’s.

[531colin]

I’ve had a rummage and I’ve got the thing (that used to be) made for the job.
1” headset which has a threaded collar which substitutes for the damaged thread. Threaded collar clamps to the damaged steerer, top adjusting race threads on the collar. To keep stack height, adjusting race has a pinch bolt to lock off not a locknut.
£25 to either Sustrans or Cyclists defence fund.
I may have pictures on file, I’ll get a coffee and have a look.
Bottom race is needle bearing exactly as A9 top bearing is balls in retainer.

Threadless headsets are made to work on the (smooth) steerer, I don’t know how they would work on a threaded bit of steerer, or on the spacers of one of those steerer extenders

[rjb]

Threadless headsets are made to work on the (smooth) steerer, I don’t know how they would work on a threaded bit of steerer, or on the spacers of one of those steerer extenders

I know where you are coming from. In an ideal world the compression ring works on a smooth steerer. You may be lucky and find that the compression ring sits below the threads but in practise they seem to work ok on the threaded section too.
The BBB one mentioned above gives a lot of extra height capability too which may be a bonus.

[531colin]

005 by 531colin, on Flickr

Thats another way to do it, while I've got the photo.
Internally sleeved with part of a steel quill stem and silver brazed an extra bit of steerer on.
Still need to find a one inch threadless headset, which I haven't looked for in years......

[531colin]

Found the pictures of the "mending" headset.

IMG_5367 by 531colin, on Flickr

Top pinch bolt fixes the sleeve to the steerer.
below that is the adjusting cup, with its own pinch bolt to lock off the adjustment . (if you could find a one inch adjusting cup with a pinch bolt, that on its own would do you. This one, of course, isn't threaded for the steerer, its threaded for its own sleeve.

IMG_5364 by 531colin, on Flickr

This is the bottom of the adjusting cup and the inside of the sleeve.

IMG_5368 by 531colin, on Flickr

Finally, the destructions! Mine doesn't have the brake hanger.

£22.50 on the box.....add at least 20 years inflation, I reckon its a bargain at £25 to charity.

[Brucey]

stronglight A9 is one of my least favourite headsets.
IMV the only 'correct adjustment' possible is to lob it into the bin. Since all headsets end up using a slightly different section of the steerer thread, you may find that there is enough undamaged thread to permit a different headset to be used. IIRC tange used to make a steel 1" headset where the adjusting race is a cone, not a cup. Not only can this be configured to be very low stack height, but it can often be used with damaged steerer threads like yours.
This works because the damage is usually confined to the part of the steerer against which the adjusting race bears. Typically the tange adjusting race uses previously unbesmirched threads well below those used by the A9 design. Normally there is enough good thread above the damaged portion for a locknut, or a spacer + locknut to be used. At one time every other cheap bike used a similar headset so it was usually possible to do something clever. Now however, finding the right headset might be tricky.

I have also saved forks with a damaged steerer by just dropping a few blobs of MIG weld onto the damaged area and then dressing back before recutting the threads, This works best if the adjusting race is steel but it allows plenty of freedom when it comes to headset selection. A downside to this method is that whether or not the weld penetrates the steerer, there is usually enough 'pull' in the weldments to ensure that the ID of the steerer needs to be dressed afterwards, although I think this can be overcome.

[rogerzilla]

If it's a really good/cherished bike with a brazed - not welded - fork, you can have the steerer replaced. It will need repainting afterwards, though.

I've had new steerers put on a couple of forks. Sometimes you find the ideal fork for a frame, e.g. a track fork with round blades, but the steerer is too short.

[Kings]

Several solutions suggested but usually with a worn thread it is often possible to recut the thread. You might find a bike shop that can do this for you, it will only take 5 minutes work if you can take the fork in. You can still use Thread Lock after if you want. Worth checking, an easy solution.

[Halla]

Thank you all for the replies.

The bike in question is a Nigel Dean World Tour 531ST with 531 forks, so quite decent.

I will take time to consider the next move as it needs another repaint.

I also need to raise the handlebars to help with advancing years .

I have just raised the bars on my summer bike to see if there is an improvement in my lower back.

The owner of my LBS agreed about the alloy A9 headset and suggested using a steel alternative. He was not so keen on using thread lock though.

Regards Andy

[mattsccm]

I created something similar to Colins . Based on an old clip type headset but I just used an ahead/threadless spacer and drilled and tapped a m5 hole. A bolt is then used as a grub screw. Brutal but works well.

[Brucey]

it is not a headset with a cone adjusting race, but the tange passage can have a low stack height so it might just avoid any damaged threads on the steerer. My guess is that the A9 has a stack height of ~40mm and the chances are that the threads are damaged at 32-35mm or so. The tange passage has a stack height of 30.2mm which probably means it normally uses the steerer threads in the 22-30mm range If you fit the tange passage with a ~9mm spacer, the spacer may straddle the region of the damaged threads whilst allowing replacement of a headset with a much higher stack.

FWIW nitto make some quill stems with a longer quill for folk that need their handlebars to be raised but they are certainly not the only game in town.