What Oil in my shock

Sander23

Active member
Aug 28, 2020
705
437
Belgium
I have bought some ROCKSHOX Maxima Plush Damping Fluid Charger 3 WT for my rockshox pike ultimate. Going to do a 50 hour service in the upcoming weeks.

Now I was wondering if I can use it for my shock to? It is for Rock Shox dampers, suspension forks and charger cartridge

I have a rockshox deluxe select plus, in the service manual it says 15w50 wich I can find only in 1 liter bottle and is quite expensive for maintaining just 1 shock
 

Sander23

Active member
Aug 28, 2020
705
437
Belgium
Thought of that to but I want to do a service more regularly as I ride 1300 km last 2 months.
And I don't want to replace the seals everytime
 

mcboab

Active member
Aug 2, 2022
76
101
NE UK
3wt oil is a country mile away from 15/50wt oil the clue is in the numbers . The latter is quite viscous thick to pour the former will be a lot less viscous. You might be able to use a generic 15/50wt though that viscosity tends to be only available in synthetic only offerings So priced accordingly IME of using that grade in my bike/car engines. Ps suspension oil has a different ask to engine use so RS oil may have different modifiers to engine oils of same grade(Wt).
 

Sander23

Active member
Aug 28, 2020
705
437
Belgium
3wt oil is a country mile away from 15/50wt oil the clue is in the numbers . The latter is quite viscous thick to pour the former will be a lot less viscous. You might be able to use a generic 15/50wt though that viscosity tends to be only available in synthetic only offerings So priced accordingly IME of using that grade in my bike/car engines. Ps suspension oil has a different ask to engine use so RS oil may have different modifiers to engine oils of same grade(Wt).
So ive been looking at oil and came acros this oil r.s.p. Damp Champ Suspension Fluid, 15WT Viscosity its 15 wt and is available in 250ml. Is this oil the same as the 15w50 recommended by rockshox? Or what alternatieve can I use
 

Shjay

Well-known member
Apr 30, 2019
835
488
Kent
3wt oil is ok with a damper service. Used a mix of 3&5wt in my Manitou Mezzer but not for lower leg service too thin 15wt is good
 

jimbob

Active member
Aug 3, 2020
518
429
East UK
I dont believe 'weight' (wt) is the same unit of measurement as 'w' as in 5w30 etc.

You can download the rockshox manuals from the sram website and they tell you exactly what oils you need to use. I ended up buying a litre of each for the lower legs of my zeb and the deluxe select plus shock. The latter was cheaper, but still expensive.

I looked into cutting corners with other oil types, and came to the conclusion that it was worth buying the right still. While an expensive initial outlay, it's small money compared to the price of the bike and the shock / fork. I'm sure some use other lubes and believe its just fine, but they reccomend those specific oils for a reason (hopefully more than just profit...). As they're not Sram branded, I tend to believe there is a technical reason rather than wanting more money having stuck a rockshox logo on the cheapest can of asda own brand oil.
 

irie

E*POWAH Elite World Champion
Subscriber
May 2, 2022
2,039
1,991
Chichester, W.Sussex, UK
I dont believe 'weight' (wt) is the same unit of measurement as 'w' as in 5w30 etc.
...

It's not the same. The 'w' in 5w30 means winter viscosity whereas I think "WT' means relative viscosity in centistokes. Or something like that.
 
Last edited:

Gyre

Well-known member
Jan 25, 2021
629
420
Pasadena, CA
So ive been looking at oil and came acros this oil r.s.p. Damp Champ Suspension Fluid, 15WT Viscosity its 15 wt and is available in 250ml. Is this oil the same as the 15w50 recommended by rockshox? Or what alternatieve can I use
15w50 is a multigrade oil where the oil you're citing is a straight 15w oil. At lower temperatures they should be the same, but at high temperatures (say, summertime bombing on a lift-served park at a large mountain) the multigrade should hold up well while with the single grade oil you might find the shock to feel underdamped towards the bottom of a run.

Or maybe you won't notice any difference and you save some money. 🤷‍♂️
 

KnollyBro

E*POWAH Elite
Dec 3, 2020
873
2,157
Vancouver
Thought of that to but I want to do a service more regularly as I ride 1300 km last 2 months.
And I don't want to replace the seals everytime
I was just wondering how many of those 1300 kms are hard DH type riding when your shock and fork are working the damper circuts hard enough to put stress on just the oil alone? The place where I get my suspension serviced (SuspensionWerx) recommends every 100 hours of use which I figure works out to be once a year as I don't really count riding up an FSR as putting much stress on the suspension. I have watched a few YT videos on doing the fork lowers, which doesn't seem difficult, but i don't see the point in just changing the oil if you are not changing the seals. What is your understanding of just changing the oil?
 

Shjay

Well-known member
Apr 30, 2019
835
488
Kent
The lower leg oil is purely for lubrication as only 10ml
I use Putoline HPX-R 15w oil it’s used in MX suspension forks
For my damper oil I use Maxima Plush which is more critical using correct oil.
 

RustyIron

E*POWAH Elite World Champion
Subscriber
Jun 5, 2021
1,536
2,410
La Habra, California
i don't see the point in just changing the oil if you are not changing the seals. What is your understanding of just changing the oil?

Whether it's the oil in your fork, shock, seatpost, or brakes, it degrades through oxidation, heat, cavitation, and contamination. The seals are to keep the oil away from air or dirt. The oil can degrade even if the seals are good. I'll frequently service all those components while leaving the original seals in place. It saves money and time. If a seal is starting to behave sub optimally, hopefully I would know it and repair it before it fails catastrophically.

Shops have a lower tolerance for weepy seals, so they might want to replace everything as a matter of routine.
 

Slapbassmunky

Active member
Aug 1, 2020
279
291
Isle of wight
So no one's pointed that the 15/50 is for air can and lower leg lubrication only? In the actual damper you should use Maxima 7wt fluid for your shock. You could use the 3wt you already have for the charger, but you will have less overall damping as it is 'thinner'. When sourcing fluid for dampers try to match the CST of the recommended fluid unless you want to make a change. One manufacturers 10wt is not the same as another's 10wt.

The 15/50 is for lower leg & air can lubrication only. Don't get too worked up about this, it's just motor oil.... Use any motor oil you have in the shed and don't worry about it too much. I use ISO100 slideway oil for all my non damper suspension needs because I've got a bottomless supply of it, and it works a treat.
 

Gyre

Well-known member
Jan 25, 2021
629
420
Pasadena, CA
So no one's pointed that the 15/50 is for air can and lower leg lubrication only? In the actual damper you should use Maxima 7wt fluid for your shock. You could use the 3wt you already have for the charger, but you will have less overall damping as it is 'thinner'. When sourcing fluid for dampers try to match the CST of the recommended fluid unless you want to make a change. One manufacturers 10wt is not the same as another's 10wt.

The 15/50 is for lower leg & air can lubrication only. Don't get too worked up about this, it's just motor oil.... Use any motor oil you have in the shed and don't worry about it too much. I use ISO100 slideway oil for all my non damper suspension needs because I've got a bottomless supply of it, and it works a treat.
Doh! Good catch.
 

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