Fork Oil Weight

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
For the stock forks, the service guy told me 1 weight. I couldn’t believe it. The guy said that's what is required in the cartridge forks.

 
I think the Ohlins R&T 43 is 7.5 weight. The only way to get that is to mix 5 and 10 in some proportion using a chart published by Motual Oils. I never new there was a 1 weight. That would be very thin.

 
Last edited by a moderator:
I use Bel Ray 7wt and love the results for me personally. Your weight, riding style, fork modifications (revalved, different springs, etc...) may all affect what oil is best for you.

 
Yamaha specifies their *01* suspension fluid which is a 5 wt. I've been using Showa SS7 for several changes in the forks. Reasonably priced, works well and matches the viscosity of the Yamaha fluid. YMMV

--G

 
What fork oil and weight you guys been using? The Ohlins R&T is priced like liquid gold.


Oy!!

The various manufacturers fork oil claimed weights vary so much in actual viscosity, you are better off picking your fork oil based on the actual viscosity (measured in "centistokes") rather than the claimed "weight". There are several resources available on the web to do that. Here is one I like: Click me (download and save that chart!)

The more important temperature for suspension fluid viscosity is the cold temp (forks never get anywhere near 100 degrees C) but you'll want to pay some attention to the viscosity index, or how it thins out as the oil heats up somewhat.

Note that the Yamaha / Kayaba 01 suspension fluid is very far down on the chart, somewhere between most 5 weight and 3 weight oils. But also note that Castrol "10 weight" oil is just above it, and would therefore be a very suitable substitute. It is no wonder that people become confused by fork oil weight ratings!

 
Last edited by a moderator:
Thanks all for some insite on this. The Bel Ray 7 sounds like a good choice for me. In the past I have been using the Olins 43, but is hard to find and the cheapest I have found it is on Amazon at $30.00 a liter and $10.00 shipping. I love the way my bike rides and handles and did not want to have to experiment with different brands and weights of oil to achieve the same results.

 
Thanks all for some insite on this. The Bel Ray 7 sounds like a good choice for me. In the past I have been using the Olins 43, but is hard to find and the cheapest I have found it is on Amazon at $30.00 a liter and $10.00 shipping. I love the way my bike rides and handles and did not want to have to experiment with different brands and weights of oil to achieve the same results.

The Belray 7 is significantly heavier than the OEM fluid. I had it in and found it too heavy. Knowing the "viscosity dance", I went down to Belray 5, using the 7 as a base from which to adjust. The front end of my bike works much better now. YMMV.

Dan

 
Last edited by a moderator:
Thanks all for some insite on this. The Bel Ray 7 sounds like a good choice for me. In the past I have been using the Olins 43, but is hard to find and the cheapest I have found it is on Amazon at $30.00 a liter and $10.00 shipping. I love the way my bike rides and handles and did not want to have to experiment with different brands and weights of oil to achieve the same results.

The Belray 7 is significantly heavier than the OEM fluid. I had it in and found it too heavy. Knowing the "viscosity dance", I went down to Belray 5, using the 7 as a base from which to adjust. The front end of my bike works much better now. YMMV.

Dan
Dan, thanks for letting me know this. I had already came to that conclusion by looking at some of these viscosity charts online. The Bel-Ray HVI 5 more closely matches the Ohlins R&T 43 specs. Ordered some today.

 
I just replaced the original fork oil (36,000 miles!!) with Belray 5 wt. The stuff I poured out of the forks was UGLY! This will now be an annual maintenance item for me (20,000 miles). I will probably do the bushings and seals next time.

 
I stand corrected (and will edit my mistake). Thanks for the correction.

I don't know why, but I could have sworn that I read that they were a damper rod configuration fork.

 
Last edited by a moderator:
Finally decided to go with the BelRay HVI 5wt. After reading the small print on the lable, it says for use in rear shocks only. Does anyone know why it should not be used in front forks? No info. on the BelRay website as to why not.

 
Stuff I used says "Bel-Ray High Performancer Fork Oil 5W". I don't see HVI on the label anywhere and the back label says it is for use in all types of forks. It could be that you have something else. You might want to check the Bel-Ray site again.

Dan

Edit: The Bel-Ray site says the HVI is a specific rear suspension fluid, designed for use in gas pressurized shocks. I have no idea if that means it will destroy your forks. I think it's worth a call to Bel-Ray before use.

 
Last edited by a moderator:
Stuff I used says "Bel-Ray High Performancer Fork Oil 5W". I don't see HVI on the label anywhere and the back label says it is for use in all types of forks. It could be that you have something else. You might want to check the Bel-Ray site again.

Dan

Edit: The Bel-Ray site says the HVI is a specific rear suspension fluid, designed for use in gas pressurized shocks. I have no idea if that means it will destroy your forks. I think it's worth a call to Bel-Ray before use.
Some suspension fluids are for gas charged shock and will oxidize and cause stiction if used in the forks. I ran into it using Silkolene in the forks. I forget what I used but it was what GP recomended in 7.5 wt.

 
I checked with BelRay and they said the HVI is synthetic and also since rear shocks are gas charged foaming is not an issue. The HVI racing formula has less or no anti-foaming additive. That is why it is not suitable for front fork use where foaming can be an issue. They said to use thier standard front fork oil. Also mineral based oil is best for front forks which is what thier standard front fork oil is.

I think I now have this all clear in my mind now. I just disasembled my left front fork, where my oil on that side was always very black when changed. The oil in the right fork was never near as black as the left one. I found the teflon on the lower bushing was worn through to the brass on one side. the top and middle were fine. Going to rebuild the right side also since I have the parts.

I have changed the oil twice in 22,000 miles, and used Ohlins R&T 43 each time. Hopefully this BelRay will give better life to these bushings. I don't ride this bike hard or brake hard. It sucks that these Genll bikes wear out forks so fast. My old Gen l Venture Royale had 70,000 mile on it and had to re-bush the forks only one time! Great ole bike, awesome motor. Thanks guys.

 
I just changed my fork oil out last weekend, and used "Motul Fork Oil Light" which is also marked as a 5 weight oil FWTW. With a cold viscosity of 20 cSt it is about 1/3rd heavier than the Yamaha 01 fork oil (14.6 cSt). I found that I had to open up my clickers a considerable amount (about one third from stock 12 clicks) to achieve a reasonably dampening response and not have my fillings shaken out. My compression is at 17 or 18 and the rebound around 16-17.

Whenever you hear people talking about where they have their dampening set it is important to also know what viscosity (not just the weight rating) fork oil they have in there.

 

Latest posts

Top