Fork oil..

Hi guys,  has anyone changed their fork oil to a heavier grade and if so what was the result in damping, handling and dive etc?

cheers..

Hi Ross,
I've not gone on a heavier grade of fork oil on my VX, but I have replaced it with new fork oil over winter as it does tend to get contaminated after a few years of service.

If you are worried about an overly 'soft' front end that dives excessively, then I would suggest you look at uprated springs - OR you could increase the length of the spacer tube that 'pre-loads' the spring. this does make reassembly a little trickier as you have to compress the spring more to get the cap back on the forks. You will see a lot of the upgraded springs are 'progressively wound (The pitch of the spring gradually decreasing at one end). This is good for giving an initial soft movement with increasing resistance to bottoming out - though may not preclude bottoming out depending on the load you subject it too !!! ..... some 'standard' springs are also progressively wound.

Not sure if it may help you .... but when I stripped down the forks on my VX, I found that a previous owner had been tinkering as the springs and spacers .... the spacers were much longer than standard & the springs appear to be off a Bandit 1200 - so that might be a possible upgrade option for you - & standard Bandit springs should be cheap. The VX has conventional forks - not sure if your VZ might have USD forks - if so the Bandit springs probably would not work.

hope that may help

   Yam

I just felt the front end was underdamped, so have changed over to 10 weight oil tonight , will need to wait for the rain and work to allow me a decent ride to assess the diference . I had a vx800 , it was orangey red with twin bates 1991 plate...I did the clutch shoulderbolt/spring shim fix as mine slipped under load and it had a weak/knackered fuel pump as it would cut out in one cylinder when the fuel level fell to a quarter ..took a while to get used to the handling too, American auto engineers are rubbish at making things go round corners .. 

I'll be interested to know your findings Ross? I'm pretty sure mine will benefit from new oil in the forks  

Hi Ross,
I forgot to mention '10 weight' is the standard spec for fork oil on the VX. I used a semi synthetic one from Silkolene, as it is a well established brand .... & it is in stock at a local motor factors shop.
Yes, the VX needs a little 'getting used to', and ain't no 'sports bike', but it handles in a competent and predictable manner ..... you just have to be vigilant in not allowing it to 'run-wide' on some bends. I always fancied one, and really love it as a knock around bike - but have done a bit of touring on it as well ... great for long days out runs, where my ageing frame is less appreciative of the more cramped riding position of a sports bike ! .....As I've got older I seem to get more pains in strange places when I go out on the CBR ... that did not seem to bother me when I was younger !

Hey Ross ... do you include Erik Buell in that list of American auto engineers ? ..... as I suspect EB is the exception to your rule !
Cheers    Yam

I managed a ride into work today and can safely say I much prefer the damping now ,much less choppy and smooth's the road bumps out better...I'm sure Mr Suzuki couldn't have foreseen the terrible states of the UK roads else he wouldn't have valved the forks for the lightest oil.
I used Motul synthetic 10W oil. I toyed with the idea of going up one grade to 5W but after searching a few forums decided on the 10W as this was recommended by some suspension tuning companies...