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How to take Teledraulic Forks apart!

First of all why am I taking them apart? Well the do not go up or down at all! and I mean even with those big sash clamps on in the photo at the top!. At this point I have no idea why not other than something is stuck, broken or rusted.

The first thing to do is to remove the wheel and mudguard etc. If you can't do that, give up now and go watch T.V. Once the wheel is off, undo the two stanchion nuts at the top of each fork. These hold the stanchions in place (Main central support bars). On the next level down you will see two clamp nuts about 8 inches below the top nuts on the outside of the forks. They grip the stanchion rods, so loosen them off. You should now be able to pull out each stanchion rod. If not tap something wooden down the top nut hole. Do not damage the internal thread! If the are really stuck, loosen them by putting the top nuts back on all but a few mm and tap it with hammer.

how to release a stanchion

If you can't get the stanchion cover off hold the cover in a vice and heat the stanchion near the oil seal until very hot. Wait for it to cool for a minute then wobble it off. If you heat and wait, it will come off easier than heating and pulling due to the different contraction rates. Now lets look at how they work....

how to take apart AMC teledraulic forks
How to do Teledraulic Forks Work?

Now we have them off the bike you can see more how they work. One of the main things you wonder is what moves, what is fixed and what is what. In a nutshell the only bit that moves is the lower black stanchion covers. They are the black outer tubes that the wheels bolt on to. The rest is fixed to the bike.

As the wheel hits a bump it pushes up against the main spring or the bike pushes down, which ever you prefer. The main spring compresses and as it does so oil in the bottom flows back and forth through the small tapered hole in the bottom of the main stanchion rod. If it nears bottoming out the taper hole is closed by the taper shuttle that is screwed to the bottom of the stanchion (inside). You don't need to removed this. As the oil flow is restricted it the forks slow down rapidly until they move no more. To stop the forks banging when the drop low (like a wheely) there is a small spring inside the cover tube as well.

The oil seal both stops the oil splashing about and leaking out and is also what the main spring pushes against. These oil seals and not that strong and the weak point of the whole fork. Leather washers are used to seat the main spring (see below) and between the main spring and the stanchion there is often rubber to act as a stanchion protector. You can use old inner tube for this if you like.

On this bike the stuck or stiff fork action was caused by the plastic bushes which weirdly shrink with age until the grip so tight the stanchion won't move. (see previous section).

how teledraulic forks work?
Leather Washers (AJS Part 010698)

These leather washers essentially act as padding for the main fork springs and there is one fitted top and bottom. So the oil seal goes on, followed by a leather washer, then the spring, then another washer.

For some reason these seem to always be out of stock and the two companies I spoke to had been waiting for months. So I decided to make a cutter on the lathe and cut my own.

The original part numbers are AJS 010698 and Matchless 021116, but you can knock out your own in an hour if you have a lathe. I used aluminium as that is all I had around and whilst not that hard it has cut them with no problem. A you can see they have turned out perfectly. In case you are wondering the leather was from an old builders work pouch but you could use a belt. The outer OD is 2 inches and the inner in my case is 1 1/8th by 2mm thick.

AJS leather fork stanchion washers
AJS leather fork washers
Reassembly

Reassembly is quite easy but remember the leather washers. The trickiest bit is getting the stanchion rods back up to the top nuts. You really need a special stanchion puller tool.

AJS Matchless stanchion puller tool

Make sure you get the right one to match the internal thread.You can make one yourself from an old stanchion nut or some people use a thin broom handle and poke it down the tube and hammer it into the stanchion then pull it back up. Once you pull the stanchion up to the point where the top of the fork retaining nuts can reach the thread, bolt up the external clamps on the bottom of the handle bar fork section (below the light holders), then fill with 9oz of oil and put the stanchion nut back on. The stanchion will stay put once you have clamped it using the lower clamp bolts below the light holder. .

Remember to buy the correct parts for the 1 1/8th (up to 1955) and 1 1/4 inch from 1955 onwards.

Comments
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Comments:

Boris Urs Fantechi   15/05/2018 at 15:14:59
Dear Sirs, we are owners of a Norton P11 750 1967. The fork springs are soften too much. We would like to buy new springs, heavy duty or progressive, if exixsting. Can you help us? Please let us have a quote comprehensive of transport to Switzerland, Europe, B Regards, Boris Boris Urs Fantechi via Max Frisch 7 6962 Viganello TI Switzerland
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Boris Urs Fantechi   15/05/2018 at 15:14:35
Dear Sirs, we are owners of a Norton P11 750 1967. The fork springs are soften too much. We would like to buy new springs, heavy duty or progressive, if exixsting. Can you help us? Please let us have a quote comprehensive of transport to Switzerland, Europe, B Regards, Boris Boris Urs Fantechi via Max Frisch 7 6962 Viganello TI Switzerland
Reply -------------->

Paul   24/06/2017 at 00:42:34
Great article, can anyone tell me the correct way to fit the close coils, (to the top or the bottom) have not found it mentioned anywhere.Paul
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 - Julian   04/07/2017 at 22:25:28
Hello, Im not sure quite what you mean? do the springs just drop in over the stanchions and i dont recall anything unusual about fitting them?
 - paul wahlstedt   05/07/2017 at 10:51:42
When a front spring is viewed about one third of the spring has closer wound coils (closer together) there is usually a recommended way to fit the close coils (top or bottom) when fitted.
 - Julian   05/07/2017 at 11:38:58
If your springs are visibly wound differently then i would fit the looser wound part in the most contained element. The only real difference would be the amount of lateral flex under load. So wider coils will require more support and closer ones less. I looked at an AJS set and there isnt an obvious difference. You can probably best figure this out by noting that the top fork slides over the lower on load so youd want a tighter spring at the top and looser at the bottom because the top cover has a bigger diameter over the spring so is less containing.
 - paul wahlstedt   06/07/2017 at 15:42:15
HI Julian,i dont believe it is to to do with lateral support, it to do with softer dampener effect (close coils)and heavier dampener effect bigger bumps (wider coils) according to my spring maker, he says that there is probably a recommended witch way to place the close coils. I have about 10 springs of different years from 1947 to1953 of different lengths for the various years and they all have closer wound coils one end.I am suggesting that the spring that you have may not be originals and that maybe you could look at, if possible some more springs that are obviously closer wound one end and you will understand what i am on about,thanks Paul
 - Julian   07/07/2017 at 16:13:01
Yes I considered the difference between the coils and their springiness but was working on the basis that as your man says, wider coils are softer and tighter coils firmer when the springs are difference and the young's modulus is constant; but when variances in closeness are within the same spring, the I'm pretty sure that the only differences would be 1) That spring travel is greater in the wider part of the spring and thus is the risk of lateral deformation is greatest. With these two factors in mind, I sure the wider coil section must go in the the tighter support structure, so typically the lower fork.



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