Fork oil weight?

[Tukt]

Hey! I'm about to get my forks freshened up a little bit by getting some new fork oil in them. I own a EC125 - 2010 with the 45 mm Marzocchi's, I find them to be pretty harsh in bumpy terrain like stones and roots, this seem to be quite popular with the stock zokes! I am well aware that an oil change won't do things much better, but what oil weight and viscosity should I aim for in order to not make things worse (hopefully xD)?

The recommended oil wt is 7,5 and I'm not really sure which oil to get

Anyone that can help me?

 

[Harry]

Hi I am no suspension expert, but lighter oil 5wt should make them softer.
Maybe some suspension gurus can add more.

 

[Harry]

Hi I am no suspension expert, but lighter oil 5wt should make them softer.
Maybe some suspension gurus can add more.

Also not all xx wt oils are created equally see the attached viscosity chart.

 

[JP4]

You can try a lighter oil to try and tune out some of the harshness. Might make a difference? Just be aware that not all fork oil weights are the same brand to brand. I think it's important to compare the CST Viscosity to know what you're working with.

I'm a nerd, so I made a table awhile back for reference.

View attachment Fork Oil CST Values.pdf

Good luck.

 

[Tukt]

You can try a lighter oil to try and tune out some of the harshness. Might make a difference? Just be aware that not all fork oil weights are the same brand to brand. I think it's important to compare the CST Viscosity to know what you're working with.

I'm a nerd, so I made a table awhile back for reference.

View attachment 6945

Good luck.

Yeah! I forgot to say that I don't know what oil there is in the forks atm because I bought the bike used a while back! I'm on a tight budget right now so I have money for one oil change and thats why I dont want it to get worse I hope someone can tell me their experience with different oils! Thanks for the charts, both of you!

 

[motopsycho87]

Go for stiffer springs with less preload and use atf dexron 6 for the fork oil (bang on 7.5w).

Too thin fork oil makes the forks use up travel too early, the first bump will be plush, every bump thereafter will be harsh.

 

[twowheels]

We mix equal parts 5 wt and 10 wt to arrive at the desired 7.5 wt oil. Pick something you can get locally, reliably ... Maxima is what we use when making the special lube for Marzocchi 45s.

 

[Zman]

If your springs are too light for your weight you may be pushing past the soft part of your suspension stroke. I run 5W oil and sometimes 3.5W oil. I heard that as the light weight oil gets hot the dampening gets unpredictable which is less of a problem with thicker oil. I have not had a problem so far but I do not run long races that would tend to heat up the oil.