Great site gtiller - thanks for the heads-up.
Don's (madass) document does have more info on the install & setup than this site though - still worth looking at.
PS: I bought mine from Don - smooth transaction
use 10w oil
Lansdowne Fork Dampers – Instructions.
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Thank you for purchasing the John Bould designed Lansdowne Fork Dampers. I have secured the rights to continue manufacturing these and I'm sure John would be pleased that the results of his efforts will continue on for a long time, to the benefit of the Norton motorcycle community.
FITTING INSTRUCTIONS - Basically it’s a case of out with the old and in with the new, some notes:
John was always very adamant that it was essential to have fork sliders in good condition, to the extent that worn sliders would not make the Lansdowne dampers work as they should and in fact could make the situation worse. So it’s imperative to have sliders in near perfect condition.
It’s possible to remove the old damper assemblies and fit the Lansdowne's without removing the lower sliders but it’s important to start off with clean parts so removing the slider makes cleaning internally easier plus simplifies the removal of the damper tube fibre washer and gives a chance to replace fork seals.
I fitted the Lansdowne dampers to my own Commando without removing the sliders, a bit tricky to fish out the old fibre washer in the bottom, (a new fibre washer is included with your new dampers).
DO NOT mix up the top fork nuts (bolts) on the Lansdownes.
DO NOT adjust or remove the brass needle valve in the fork nut (bolt).
DO NOT use a 3/16" allen key to tighten the new damper tube retaining bolt, use a 5mm allen key.
DO NOT remove the fork spring retaining nut on the new Lansdownes, (the new Lansdownes come with new standard fork springs).
DO NOT remove the fork springs.
Fit the new dampers as they are supplied to you.
So, assuming your sliders are fitted, remove the top alloy fork nut (bolt) with the brass needle valve attached, the alloy fork nut (bolt) is supplied only hand tight.
Be careful not to lose the small needle valve spring when removing the top fork nut, its located underside of the fork nut.
Fit the new damper assembly with new fibre washer attached in to the fork assembly.
Fit and tighten the damper tube retaining screw with alloy washer using 5mm allen key (not supplied).
Push up slider so fork spring is protruding through the top yoke 3" or so.
Slowly pour in 150ml of fork oil.
Fit top fork nut (with speedo/Tacho and washer) and tighten against fork spring retaining nut (17mm open end spanner) and use a 12" adjustable wrench or 1-3/8" open end spanner to tighten the fork nut (bolt).
Repeat procedure for other side.
Fit wheel, brakes, fender etc.
With front brake applied pump the forks about 10 times to prime the dampers.
Now and only now you can adjust the brass needle valves with the 2.5mm allen key (supplied).
The fork nuts are supplied with the needle valves adjusted 3 turns out, this is to aid in priming the dampers.
With the 2.5mm allen key rotate clockwise the Compression (C) needle valve approximately 3 turns until it bottoms out, DO NOT force it, you will know when it bottoms out.
Adjust the needle valve anticlockwise about 1 to 1-1/4 turns and then pump the forks with the front brake applied, you will feel the dampening effect at work.
Adjust it out or in about 1/4 turn at a time to get a feel of the dampening effect.
When you think it’s somewhere near ok then repeat the same procedure to the Rebound (R) side.
Lansdowne Fork Dampers – Instructions.
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I found the rebound side initial setting to be somewhere around 1/4 turn out to start with. The
rebound side seems to be more affected with smaller adjustments.
Now with small allen key kept handy start riding and adjusting the dampers to your liking,
remember only make the smallest adjustments.
You are done. I can always be contacted firstname.lastname@example.org
Remember, I am not the expert on Lansdowne dampers, I am only the manufacturer and Norton nut.
There is much discussion on the Lansdownes over the years on accessnorton.com and its worthwhile
doing some research there, I'm sure many of you already have