Fork triple clamps

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Fork triple clamps

Postby GregT » Mon Dec 16, 2019 7:00 am

Hi - I recently liberated a set of teledraulic forks from a friend's cache of assorted parts. The aim is to use them on a 50's lightweight race special - a bitsa, not to restoration standard.
What has been written previously about pulling out OE bakelite bushes is correct in every frustrating detail - but getting the legs hot enough and applying penetrating oil does help - ultimately....
However what has got me curious is the triple clamps. The top one is straight, no probs. The lower is bent - both longitudinally and laterally. Luckily the stem appears straight. Heat and patience will take care of the misalignment.
But - checking the offsets, top and bottom it appears that this set has stanchions not parallel to the stem. I've struck this before - but on exotica, not British. I'm always prepared to accept there are exceptions but would like to know if this is correct.

The top triple has 42G3 FF21 cast in - and M12 A5 stamped on.
The lower has FF17 cast in

The forks use 29mm stanchions

Have I got a mismatched set - or are they supposed to be non-parallel ?

Thanks

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Re: Fork triple clamps

Postby Rob Harknett » Mon Dec 16, 2019 10:15 am

Looks like you have war time WD forks there. This will help you see what you have in confirming the parts / numbers correct.
http://archives.jampot.dk/book/Spares_l ... t_1050.pdf
You may have problems getting things apart and out. Getting parts back in may be more of a problem. Unless you can make the new parts yourself.
Perhaps some of the WD lads will come along and tell you if they know who's making new parts or how they overcome the problem of no repro part being available.

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Re: Fork triple clamps

Postby alanengineer » Mon Dec 16, 2019 12:58 pm

A photo might help, but the later ones were non parallel from front to rear
Last edited by alanengineer on Fri Dec 20, 2019 9:23 am, edited 1 time in total.

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Re: Fork triple clamps

Postby SPRIDDLER » Mon Dec 16, 2019 5:03 pm

Welcome to the website, Greg. :beer:
If it's of any help here's a set of yokes from a '54 bike. The 1 1/8" (c. 29mm) stanchions seem to fit parallel to the stem. Later bikes had 1 1/4" (c. 32mm) diameter stanchions.
(I'm not sure whether as a non-subscriber you'll be able to see the photo).

CIMG0004 (640x480).jpg
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I poke badgers with spoons.

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Re: Fork triple clamps

Postby GregT » Mon Dec 16, 2019 5:33 pm

Thanks for the quick replies. Yes, I can see the pic. Lower yoke same as mine, upper quite different. Mine is flat - albeit with a cast "tubuilar" section across the front - and no bar mount provision.
My forks would appear to have a chequered past - the stem is welded in which suggests replacement at some point. The offset difference is too great to simply be the stem welded into a sloppy hole.

I'm accustomed at this end of the world to making replacement parts. Top bushes won't be a problem. The stanchions are of course pitted but not too bad on the operating area. For the amount of use this bike will see, it's probably not worth sourcing new stanchions. Seals I think I can source locally.

At least I know the non parallel yokes could be OE. From talking to family friends in the trade post war I know NZ got some very odd stuff. The export drive was such that machines were built from what was on hand at the time...

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Re: Fork triple clamps

Postby Rob Harknett » Mon Dec 16, 2019 7:45 pm

My first reply gave a link for a WD parts list. It was then said a picture would be handy. There was a picture in the parts list that showed the crown in question is the same as the picture in the parts list. It shows the same part number the person stated in his first mail. A picture of a crown was later shown that differed from the part in question. I took the trouble to do some research on part numbers, confirm what you have was a WD fork as seen in the parts list. Was I wrong? Did you look?

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Re: Fork triple clamps

Postby GregT » Tue Dec 17, 2019 2:39 am

Interesting. I realise that I'm on probation so to speak, so if the moderators don't like my reply, at least pass it on to Mr Harknett please.

No it was not of help. I'm on slow dialup and having now found the time to download 22 pages of which two pics on one page were of any interest, I can confirm that.
The parts nos on my pieces don't match that list. Most of the exploded diagram does match what I have - but it doesn't tell me anything I didn't already know.
A simple reply to the effect that some sets of forks are known to be non-parallel would have sufficed.

Thanks for the time.

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Re: Fork triple clamps

Postby matchless » Tue Dec 17, 2019 4:00 am

Hi, From memory there are about 6 different tree assemblies introduced from 1940 to 1966 and 4 of these were for the 1-1/8" fork legs. So it may be difficult to know exactly what you have got, without some images. However, if not worried about originality, then you can mix and match. Bear in mind that the later manufactured models, which were a malleable casting (Not alloy) were a lot stronger than the early WD type.
I note the fork legs had to be set at a different angle to the stem, in order to get the correct trail angle. Compy models were set differently again (That's another story).

Happy Hunting...........David

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Re: Fork triple clamps

Postby Rob Harknett » Tue Dec 17, 2019 10:31 am

OK . Even with pics of all yokes used , I do not think will tell you what you seek. What you have got now is a result of a war time bikes end result after at least 3 years of war, followed by another 75 years of make do and mend. FF17 with number cast was first used on late 30's girder fork bikes. It seems the top yoke changed a bit, if parts were not available during war time mods were made, as your top yoke has something additional stamped, it does suggest in war time a mod was made to this part. Do not expect to find your bike matching up to what it was 80 years ago. I will attach a parts pic of what it was 80 years ago in 1942. Just the one page from the book. If I knew the frame and engine number of your bike I could perhaps find a parts list from the WO contract your bike came from. Which may be contacts from bits you bike same from. As it probably now bits and spares from many bikes. Its been made/ bodged to go together.
Ashampoo_Snap_17 December 2019_10h07m42s_001_.jpg
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Re: Fork triple clamps

Postby Rob Harknett » Tue Dec 17, 2019 10:35 am

Theres a top yoke on e bay right now looking like the one in the parts list page I showed.

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