Page 2 of 2

Re: Fork oil weight

Posted: Mon Dec 12, 2011 5:52 pm
by JoKing
Hi,

is here somewhere a link to the "how to" for fork adjustment?
I fitted my fork with progressive wilbers springs & am looking for the right amount & type of fluid.

Currently i think i will take 7.5 or 10W, (110kg riders weight, racetrack & country roads...)

Re: Fork oil weight

Posted: Mon Dec 12, 2011 6:15 pm
by paso750
what does the manual of the Wilbers springs say ?
I`m using Hyperpro springs and if I remember well the oil that came with it was a 2.5 so totally different than original.

G.

Re: Fork oil weight

Posted: Mon Dec 12, 2011 7:38 pm
by JoKing
Didn`t come with manual :-/.
Is a used set with 5tkm from a friend of mine who crashed his 907 some years ago...

/edit: are the hyperpro springs progressive as well? I think i should try 5W then...

Re: Fork oil weight

Posted: Mon Dec 12, 2011 9:39 pm
by paso750
yes they are.

Re: Fork oil weight

Posted: Wed Dec 14, 2011 9:37 am
by blazing928
hi
from memory ASR suspension in Oz, put 5w in the compression leg and 10w in the rebound leg, and around 175mm oil level.

Re: Fork oil weight

Posted: Wed Dec 14, 2011 5:24 pm
by JoKing
The compression leg is the one with the anti-dive system, right?

I did not know, that the function is devided...

Re: Fork oil weight

Posted: Thu Dec 15, 2011 11:05 am
by blazing928
yes different in each leg, but not sure about any anti-dive! The bike does dive under brakes.
I reckon that's a function of the compression circuits, slow speed and high speed.
There is an article in the tech section about the M1R fork and search posts about them.
There is a mod where a hole is drilled in the leg to let the oil move faster at slow speeds , therefore making it more supple. This was done to mine, but I never really rode the bike with stock forks so I can't give a comparrison.
i had springs to suit my weight and riding style, and ASR spoke with another company in Sydney who advised him on the oil weights. Also fitted a Wilbers rear shock.

As an aside my new MTB fork, a 2010 Magura Thor 140ATM, doesn't collapse much under braking but still remains supple and absorbs a larger bump under brakes. They tell me its because the low speed circuit is quite firm so it stops it the collapsing under brakes. It feels quite frim and as if there is a lot of stiction when I bounce on them but when ridden they are lovely. Also very stiff and mated to the bike, a Liteville 301 rips corners beautifully.

Re: Fork oil weight

Posted: Thu Apr 12, 2012 8:17 am
by JoKing
I just assembled the both fork legs.
Filled them w. 440ml(!) oil in fully compressed state, w/o spring in them.
That leads to 160mm air cushion (the 907 manual says both, 160mm (twice) & 180mm (once), so i do not know wich is "correct", but i even wanted to have a strong progression because of my weight & size (115kg @ 2,12m).

Left leg: 5W, right leg: 10W.

Now the question:
I can compress the left leg fast with nearly no resistance (except the spring load), and it travels back very fast as well.
The right leg shows much more resistance during compression, and moves back much more slowly. This can not be all caused by the difference in the oil.
I think the right leg has to move back very quick as well.

Is this behavior correct?
I think i did assemble everything the right way...

Re: Fork oil weight

Posted: Thu Apr 12, 2012 9:42 pm
by ducbertus
I've installed White Power progressive springs.
fully compressed without springs the air chamber in upright position is 160 mm.
the oil is a 5W10 oil, if I remember well.
the right leg raises much faster than the compression stroke.
the left leg I can't tell for sure about the difference in speed in compression and decompression.
generaly spoken I'm happy with the M1R.
if your right leg decompresses slower as the compression stroke, there something wrong in the way you stacked the shims in the decompression mode.
as the left leg only has restriction in the decompression stroke, the feel can be completely different than the right one as their function is different.

Bertus

Re: Fork oil weight

Posted: Fri Apr 13, 2012 5:12 am
by JoKing
Fu.. so something has gone wrong. I do not know what, because the shimming thing i did not touch...