Which fork oil and how much ?

[Ian-man]

Hi all, Since I got my R6 shock converion last year which is amazing, my front forks have felt even worse. I have looked into full rebuilds with cartridges and at the other end of the price range, Hagon springs.
For the mileage and riding I do I have decided to buy K-Tech springs so I can specify spring weight and new oil and seals. I really fancied the fully monty cartridge conversion but there coming in at £480 ish and that's a whole lot of wonga and tbo I don't think I need it for my 'steady away' making progress style.
The big question is, while I am keeping the standard forks with upgraded springs for my weight/style. Which grade oil should I use.
Standard is 5w, but some people say thinner as damping is slow on standard, others say thicker. Some say standard oil level some say a bit more oil.

Is there any others out there that have tinkered with the oil as they have been on a budget/ being pragmatic.

[Falcon 269]

A lot depends on your weight and whether or not you routinely carry a pillion and/or luggage.

Standard is 7w.  Thinner improves hi-speed damping response but at the possible expense of increased dive on hard braking.  Springs, though, play into this equation - there's no simple answer.

FWIW, I found the Hyperpro spring set to work well with the Gen 1.  They're progressive springs but the initial and secondary rates are better-matched to the bike than the Yamaha originals.

[mcyoungy]

Standard is 5w? Depends who you talk to. Yamaha claim it's 0w. SAE wt is not a good number to use tbh when discussing fork oil. You need to look at oil viscosity and quality. you will find that one man's 2.5w is another's 15w as the viscosity is the same.
 
This wiki gives some good info on oils:
 
http://www.peterverdone.com/wiki/index.php?title=Suspension_Fluid
 
The OE fork oil is listed there as Yamaha 01 fork oil - it's a Kayaba oil.
 
 

[Ian-man]

Thanks guys, my Haynes lists the oil as 5w so maybe I will go with that or 7w. I will look into the kayaba oils too.

[mcyoungy]

The Kayaba/Yamaha stuff is a bit expensive.

[SEPTIKANGEL]

About to do new fork seals on my Gen 1.  Gonna go for the 7.5 weight Motul to refill..... How did you get on with the 7 weight yourself?

[Ian-man]

Got a message back from k-tech about their recommendation.

Good quality 10w oil with 145mm air gap.

[Boris]

When I recently overhauled my Gen 1 forks, I changed my springs for Hagon ones, which came with 7.5w oil. I'm really pleased with the firmer front end feeling.  Plus, the excellent advice I received from Hagon.

[mcyoungy]

Got a message back from k-tech about their recommendation.

Good quality 10w oil with 145mm air gap.

Silkolene Pro-RSF is good stuff.

[G60]

My springs are also being replaced when I get the time, but I've never changed fork oil before - how much will I need?

[mcyoungy]

a litre will be plenty

[Ian-man]

Got my K-Tech springs in, they are linear so not progressive like the std ones. K-tech recommended 10w oil with 145mm air gap so thats whats been put in.

The old oil was GREY and STANK. On initial impressions it seems much better. Not so much diving when breaking and soaking up the bumps better.

[G60]

a litre will be plenty

Cheers.




Ian - I am also fitting K-Tech springs to mine. Did you do the seals as well?

[Ian-man]

Yes, fitted new genuine yamaha seals.

[Motopsycho87]

Bringing up a dead post here, but in the name of "sharing is caring".

If you want 7.5w oil that will last almost forever, and look after your forks. Buy an atf dexron 6 (vi). It's quite rare in the UK, but valvoline maxlife atf is pretty available.

When you bare in mind that a fork oil is essentially a hydraulic oil. That's is. Some have anti foam and anti wear additives, but they're all rubbish.

Atf is a hydraulic oil, gearbox lubricant, seal conditioner, anti corrosion etc. Dexron 6 is a spec that requires a drain interval of 100,000 miles normal driving, and 50,000 miles "severe use".

We all know how disgusting fork oil gets after a long period of time, but I've used it on my enduro bike for 2 years now, and it comes out looking almost identical to how it goes in.

Only reason I'm plugging the valvoline is because it's the only atf dexron 6 I've found in the UK. And it's viscosity falls right in the 7.5wt region which is perfect for the fazer and correct for the marzocchi forks on my crosser.

Have a look at this link and see just how rubbish most fork oils are, and how some manufacturers use literally the same oil for 3 oil weights... http://mahonkin.com/~milktree/motorcycles/fork-oil.html

[happycallis]

Bringing up a dead post here, but in the name of "sharing is caring".

If you want 7.5w oil that will last almost forever, and look after your forks. Buy an atf dexron 6 (vi). It's quite rare in the UK, but valvoline maxlife atf is pretty available.

When you bare in mind that a fork oil is essentially a hydraulic oil. That's is. Some have anti foam and anti wear additives, but they're all rubbish.

Atf is a hydraulic oil, gearbox lubricant, seal conditioner, anti corrosion etc. Dexron 6 is a spec that requires a drain interval of 100,000 miles normal driving, and 50,000 miles "severe use".

We all know how disgusting fork oil gets after a long period of time, but I've used it on my enduro bike for 2 years now, and it comes out looking almost identical to how it goes in.

Only reason I'm plugging the valvoline is because it's the only atf dexron 6 I've found in the UK. And it's viscosity falls right in the 7.5wt region which is perfect for the fazer and correct for the marzocchi forks on my crosser.

Have a look at this link and see just how rubbish most fork oils are, and how some manufacturers use literally the same oil for 3 oil weights... http://mahonkin.com/~milktree/motorcycles/fork-oil.html

Bumping an old thread .is this the right stuff? https://www.opieoils.co.uk/p-85494-valvoline-atf-automatic-transmission-fluid.aspx


Cheers


Mat