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Hi,
Any tribologists running around in here that know hydraulic oils? I'm getting tired of paying 20 bucks for a qt of 5 w fork oil when I know most of it is rebranded hydraulic oil purchased in bulk.
Since iso 22 hydraulic oil is ~ 5 wt.. .have any of you used off the shelf oils from various mfg's in your fork and shocks?
Interested to know your thoughts... Thanks.
Any tribologists running around in here that know hydraulic oils? I'm getting tired of paying 20 bucks for a qt of 5 w fork oil when I know most of it is rebranded hydraulic oil purchased in bulk.
Since iso 22 hydraulic oil is ~ 5 wt.. .have any of you used off the shelf oils from various mfg's in your fork and shocks?
Interested to know your thoughts... Thanks.
The maxima 5 wt I put back in it was kinda clear but still felt like, looked, smelled hydraulic oil. I used the cheaper Maxima, seems like it was 12 bucks a qt. The synthetic is probably 4-5 bucks more a qt.
I spent most of my career in and around the oil refining industry. Retired from a very large Industrial Tech company. We did process control systems for refining industry. Before that I worked for the old Kerr McGee oil company, It was interesting talking to the old time chemist. Oil is dang near oil. The dealers and others used to talk about Yamaha lube 2 cycle marine oil and the special additive packages it had. Was the same oil that CITGO put in bottles that said Citgo on the jug for less than half price.
I don’t know what wt hydraulic fluid is or if it states it on the jug, but if it said 5 wt chances are I’d use it.
I had a friend that worked at one of the large shock companies and they used to use Exxon J13 then J26 oil... this is stuff for tractor rams. It's not rocket science.
The Shop
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Free shipping: VITALMX
Luxon 4-Post Bar Mounts
$189.95 - $239.95
CST of the hvi22 is 22@40 and 4.4@100deg. A bit thicker then the maxima 5wt which was around 16@40 and 3.5@100.
Forks though… run whatever 5w you want.
Good viscosity info here:
http://www.peterverdone.com/suspension-fluids/
For the shock you want something with a high viscosity index to give consistency with the heat as mentioned , but the higher the VI normally the quicker they shear so servicing regularly is important.
I spent time formulating fork oils, shock oils, and industrial hydraulic oils. There are similarities to all three in terms of performance requirements. There are also a few differences that should be accounted for during formulation.
I would sometimes use a similar base chemistry for additives, and use some similar base oils, but each product absolutely had its own formula tailored to the application and wasn't just a rebrand.
Much of the specific properties mentioned above were formulated into the products to either bolster them above and beyond what a "basic" hydraulic oil would provide or to add properties that a pedestrian hydraulic oil might not have built in.
I can't speak for every brand, but the ones I have knowledge of (or did while I was still doing that) absolutely justified the higher price tag.
When I worked on hydraulic mining shovels it was common to see reliefs come out in pieces from the erosion caused by the oil flowing over them. Oil would still last 4-6000hrs based on samples. Pumps working at 1100l/min and 5000 psi.
If you never play with your valving and just change oil as a maintenance item then cost is a non issue. I have changed valving multiple times in a day so I appreciate the savings.
Pit Row
I can’t imagine people reuse oil from their forks no matter how low the hours are, is that really a thing?
It doesn't add up to me that someone who is fussy enough about their suspension to revalve multiple times a day is also fine with using fleet oil that is not the exact specified weight. But if it works it works
I m one of those guys that is in the valving stacks on my bikes somewhat frequently. And I don't like to reuse the oil due to possible particles getting in to it as one gentlemen mentioned. Even if the fork or shock only has 30 mins on it... it's hard to not have stuff get into it when taking it apart.
I did have an interesting conversation today with a guy that selected and formulated the oil packages used at one of the major suspension companies. I asked him about using off the shelf hydraulic oils from various big oil companies. He thought the additives to those base oils (so to speak) were important enough that you would want them. Thus, he steered me away from standard off the shelf hydraulic oil.
I wouldn’t describe myself as fussy, I just enjoy tinkering and being able to feel the effects back to back on the same track/conditions.
As I recall, when I did a fork oil, I tended to up the anti-foaming characteristics, try to get the friction coefficients (static and dynamic) down, and I didn't tend to worry too much about the VI, so that freed me up to save some cost on base oils.
The rest of the typical hydraulic additives were pretty good for anti-oxidation and wear resistance to round out the product but sometimes extra anti-wear might've been needed.
For shock oils the biggest thing was always viscosity index. I remember trying to hit the numbers needed there was always very pricey.
Who did you do work for?
This has been a while back and may no longer be a thing, but I was talking to a Showa factory tech at a national and we began discussing oils. I told him a friend of mine who's son was a top level Team Green rider used aircraft hydraulic fluid 5606 in his suspension. He sort of smiled and started telling me all the properties like VI, temp resistance, etc. and how the newer was fully synthetic because it was less flammable in aircraft. He said it was being used currently (then) in many factory suspensions. His name was Graeme Brough and he was Honda's Showa guy.
Interesting info MX317...Never thought to look at that industry.
I just dug this up... See below underlined.
Applications:
AeroShell Fluid 31 is recommended for use in aircraft, ordinance, and missile systems operating from 40°C to +205°C . This fluid should be considered for use in auto pilots, shock absorbers, brakes, flight control systems, hydraulic servo-controlled systems and other systems using synthetic elastomer seals.
An increasing number of aircraft manufacturers now recommend use of this type of fluid in aircraft hydraulic systems in preference to mineral hydraulic oils. This move has been prompted by need to use fluids with better fire resistant properties.
AeroShell Fluid 31 is also approved for use in the Honeywell (formerly Garrett) cooling turbine (cabin air compressors).
Increasingly this type of hydraulic fluid is being adopted for use in hydraulic systems of military aircraft in place of mineral hydraulic fluids. AeroShell Fluid 31 is a synthetic hydrocarbon oil and should not be used in contact with incompatible seal materials. Refer to the General Notes at the front of this section for further information.
AeroShell Fluid 31 is compatible with AeroShell Fluids 4, 41, 51, 61 and 71 and can be used in systems designed to operate with MIL-PRF-5606, MIL-PRF-6083, MIL-PRF-87257 and MIL-PRF-46170 fluids.
I didn't use to disclose, but since my website is no longer a thing, I don't think I'm sharing any sensitive info, and it is likely a bit outdated anyway, I figure it isn't a big deal.
I spent a number of years formulating for Bel-Ray some time ago.
If I'm sharing too much info, I invite @cwolf96 to come shut me down for blabbing.
@MotoTribology your legacy still lives on! Great to see you're still active on important topics. Thanks for bringing more insight to this. You said it perfectly, there are similarities between industrial hydraulic fluids but there are also differences accounting for during formulation. Bel-Ray's Fork Oil is application specific and purpose built for forks. It is NOT a relabeled industrial hydraulic fluid.
If you're constantly taking apart your suspension and tinkering with the valving, to each their own. However,I strongly recommend at some point, give the industrial products you're claiming to use a longevity and durability test against a quality application-specific product and compare the differences - that's where you'll see the benefits.
For 95%+ of moto customers, we're servicing our stuff maybe once a year? Go with a quality application specific lubricant and your suspension will thank you. There's a reason why Factory Connection, Pro Circuit and all major suspension companies use name-brand suspension lubricants.
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