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Discussion Starter #1
"I routinely switched to 30-weight from the original fork oil (about
15-weight) in my Japanese motorcycles [with the antique-style damping rod forks], hoping to get more rebound damping over low speed, high-amplitude bumps on smooth pavement, and it worked fine when I was riding back roads at slightly over the speed
limit...

But, when I tried to race the same machine on a closed course circuit
at twice the usual speed, the front suspension was chattery, couldn't follow the pavement, and I had all sorts of wobbles and weaves...

Besides being chattery at high stroking velocities, forks with too
heavy an oil will "pump down" at lower stroking velocities. The front
of the motorcycle will sit a little lower because the oil can't move
through the damper rods fast enough and the machine will steer quicker
for a while after the forks pump down..."

They collectively did recommend cartridge emulators and spring replacement as a better, more expensive solution for cheap damping rod forks.

I found that 20w-50 engine oil a little higher in the forks than stock works great in my cheap cruiser forks at under 85 mph for my riding style, but I still bottom out the cheap back shock on bigger bumps and I get my ass off the seat to protect my back. I would never add this heavier oil to my ZZR600 cartridge forks.

from Thicker Fork Oil Available Or?

Racers will sometimes use a chart like this to experiment with different fork oil weights:

Fork oil weights
 

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The Indifference Engine
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I'm a little confused as to why you think that oil developed specifically for lubrication purposes and designed to be used at HIGH temperatures and HIGH pressures (plain bearings) is a good idea to put in your forks, where you're relying upon the oils ability to maintain a consistent viscosity across a relatively minor temperature range where its chief requirement is to simply move through small holes at a consistent rate?
 

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Discussion Starter #3 (Edited)
Why I think that oil developed for HIGH temperatures and HIGH pressures (plain bearings in engines) is a good idea to put in my cheap cruiser forks:

My cruiser forks are based on ancient piece of shit 1970s damper rod technology, with cheap springs that quickly lose their original stiffness, and fork valving and a seat height for short Japanese people that weigh about 90 to 110 pounds. High quality fork oils (like the link I included in the post above) would not suddenly turn these forks into modern Ohlins quality.

I like 20w-50 Valvoline Maxlife engine oil in these forks because there is a newer oil seal conditioner added, engine oil is designed for cold starts and low pressure camshaft bearings at idle, it costs less than fork oil, and it is heavier than the original red 7-weight ATF fluid that Honda put in these forks when they were new, which is terrible for my 205 pounds and my riding style. I plan to use the same engine oil again when these forks need oil replacement. I think one of the fork seals started to leak at about 2,000 miles because the cheap-ass original fork oil was good at letting dirt get into the fork seals. Cleaning the original fork seal fixed the leak.

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From the above link, here is a list of 12 better fork oils, from lighter to heavier, and with less viscosity change during all day riding based on independent testing, if you want to pay for a higher quality fork oil:

1.Golden Spectro Ultra Light
2.Silkolene Pro RSF (2.5 wt)
3.Penske Lightweight
4.Motul 2.5-20
5.Red Line (Light, Yellow)
6.Spectro SX 400
7.Red Line (Medium, Red)
8.Bel Ray HVI (10 wt)
9.Silkolene Pro RSF (7.5 wt)
10.Golden Spectro (Light)
11.Bel Ray HVI (15 wt)
12.Red Line (Heavy)
 

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The Indifference Engine
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So what you're really saying is that you put a higher viscosity oil in without any thoughts to the consequences. It does make more sense to use a heavy engine oil rather then something developed for forks (where there are also multiple weights for you to try).
That and I'm super interested in how the oil under the oil seal prevents dirt and dust from getting past the dust seal...


You should stop offering people advice.
 

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So what you're really saying is that you put a higher viscosity oil in without any thoughts to the consequences. It does make more sense to use a heavy engine oil rather then something developed for forks (where there are also multiple weights for you to try).
That and I'm super interested in how the oil under the oil seal prevents dirt and dust from getting past the dust seal...


You should stop offering people advice.
Welcome to the world of Jeff. He has no idea what the fuck he is doing. Ever.
 

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Discussion Starter #6
People with my type of cruiser (600cc Honda V-twin) often put a piece of square steel rod in place of the back shock and add 6 inch over front fork tubes.

It is their bike, and their risks for any changes they make, and I am sure they would also tell you to go fuck yourselves if you do not like their freedom of choice.
 

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You are our version of the retarded fucks who remove their shocks and rake out their cruisers.

I would call them retarded, just as I call you retarded. Someone with Downs could tell me to go fuck myself, too, but that doesn't make them any less retarded.
 

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Discussion Starter #8
I choose to add heavier oil in my cruiser forks because it works better for the reasonable speeds that I ride on public roads, with its low quality suspension. It would totally suck for racing, but my cruiser has nothing to do with racing. The low quality suspension and weak front brake remind me that this bike will easily get out of control in a faster corner, no matter how many years of experience that I have for dirt and street riding.

Something to think about, in between calling people retards:

"I simply had to, absolutely had to, root out of my Riding, those aspects of Racing that so monumentally endangered that Mortality.

Racing adds the factor, "…faster than those Others." One applies hard won increments of shaving time from travel, say, on those last feet approaching a corner, directly better than that other guy is doing right now, in order to get by him/her or get away from them.

One is practicing Maximums. And, one is practicing Maximums better than anyone.

What's up with a Street Rider? Is it filled with smooth 50 foot wide race track surfaces? Is it filled with the need, real need to cover ground at a maximum rate? Is it composed of Beating Joe?

What's Reality, here on The Street? What's left, what's aside that… is Fantasy.

To me, these folks are easy to spot. Leather-clad aboard their Sport Bikes, they are zipping and zooming along in ways I do not feel. Out through the twisty roads and the long straights of his country they are acting like, acting, not being, Racers.

They don't "race" very well. Their speed through the populated farm country is inappropriate. They dive into blind, dirt strewn corners with foolish abandon, and strike lean angles that that make recovery from surprise encounters impossible. Their entries are too wide, their apexes too tight and always their bikes are settled only momentarily.

I can spot all kinds of things that are not here with me: That need for the last increment of entry speed; That last degree of lean; That upshift at redline to a top level gear. I see too, Doubt. I see Inconfidence. I see the need to beat Joe.

I'm out here on The Street. But, I'm seeing Racing. I can see they don't know what "it" is. They can't or haven't separated the various "its" of general life, personal life, racing, Street Riding. Doing one thing and having present thoughts and motivations of another thing is not "reality". It's a fine definition of Fantasy.

Hell, you're already riding faster than is a danger to you now. Why do you want to go faster??!!

Maybe you ought to learn how to be in control of you and your motorcycle first.

Maybe instead of learning how to make a bike go faster in the pristine conditions of a race track, you'd be better served to learn how to tell, and then come to understand what's going on right here on The Street, and the skills to handle those things you potentially face every day.

Now, I'm not talking about a neophyte Rider. This person is a Good Rider. They don't crash. They don't endanger me.. much. And they don't have Close Calls - that they are aware of.

Get it? In many ways, they are a Marginal Rider. It's easy to understand that concept when looking at Some Harley Guy. He racks up a grand total of 1,250 miles a year, 25 miles at a time riding to and from The Meeting Place. He gets there and back. Every time. I mean "every time" qualifies as a "Good Rider" in my book.

But, heck, does this cat see radiator fluid on the crosswalk lines at intersections? Or, how well can they stop that long fork crate for a mini-van blocking the entire road at a driveway out onto the middle of a blind curve? Did they ever learn the BEST way to handle inadvertently entering a corner too fast? How much do they love their rear brake? Or "over-love" it?

How do they operate under STRESS? The stress that inevitably arises in Street Riding?

Is this Harley Joe ready for a track school? Will they come home from a track school better served? Or will they be emboldened to further overstep their limited Basic Skill Set?

How well trained is The Rider? How well can The Rider "cowboy up" when The Street Environment suddenly throws up one of its Surprises? How much "thinking" will they need to do to handle Surprises? Will they have the time to "think" themselves out of Danger?

Does going faster on a race track help with those things? Those always needed things?

Sure, I want my friend to learn better about what corners are composed of, about how to make the bike strike appropriate arcs through them, about becoming comfortable at greater lean angles. But, I know those things can be taught and their basics gained, and then practiced every day - far away from the race track.

And, away from The Race Track, and the Racing School, they will also be away from the impetus to seek maximums that are wholly inappropriate to Street Riding.

And, away from the track, they can devote themselves to being able to handle a motorcycle when through Speed meeting Condition, on the street or track, it starts to go to hell in a hand basket. And it will do so out there in their track school at some point. Just as it even more assuredly will out on the street!!

I look on Keith Code as a friend. He's bright, smart, and a loving and caring man. He is devoted to helping Riders ride better on the track. His approach to dealing with Basics on upward allows transference of information to street use. He has much to offer us.

I love to spend time with the Pridmores - and their various staff. They ride and teach well, and much can be learned from them. Reg and I disagree on many points about street motorcycling. That's probably true of our views on wine too - so it amounts to a "So what?" I'd never steer anyone away from gaining experience with them.

Freddy Spencer is a Racer. He's fun, funny, and full of insight into handling a motorcycle. But, would you really want to follow him around on the street?

And that's my point. G** Dammit!! Please, apply the majority of your concentration to learning how to ride your motorcycle in the Public environment. It's full of dangers to your Wellbeing that don't exist on race tracks, and those dangers are not well met by the special skills one can overly concentrate upon to do well in a Track environment."


from Looking at The Difference between Street and Track Riding Skills - BMWSportTouring Forums
 

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The Indifference Engine
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Just because you're incapable of differentiating between the track and the street does not mean that we are not able to do so. That being said he is talking ONLY about mindset, not the skills or ability that we hone either on the street or at the track. Basically, any learning is good learning so long as you are able to apply it correctly. For example: knowing what maximum braking on the track feels like makes an emergency stop easier on the street.

Your point is largely irrelevant. We are questioning the sense in using engine oil in your forks when there is tailor made fork oil of a heavier weight that will help alleviate the issues you are having.

Of course a gold valve kit from race tech is under $200... and on a bike that costs upwards of $4000 it hardly seems like an unreasonable expense for the sake of comfort and control.
 

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That Fighter Guy
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Another concept abortion by Jeff.
 

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Discussion Starter #11
Some more advice that I found for forks:

"Most folks who stiffen their suspension (either by stiffer springs or by stiffening up the damping) say their bike works better, but unless you do a proper setup and know what you're doing, you're probably making things worse.

If you're just using stock springs (either because they are the right ones or you haven't resprung), then you probably want to keep pretty close to the stock fork oil viscosity. Even with heavier springs, I wouldn't make a drastic change in viscosity - if the springs are 20% stiffer, I'd tend to put in 20% thicker fork oil if I made any change at all. And if I decided to make a fork oil change from stock, I'd first start with fork oil height (air volume) before I'd change fork oil viscosity. Fork oil viscosity would be my last fine-tuning thing.

The fork oil mfg's are notorious for not using consistent viscosity measurements and/or naming their fork oils with misleading names, partly to satisfy buyers who think a bigger number is better.

Mfgs these days generally specify very low-viscosity fork oils and the forks are designed for this - stick a thick oil in there and the fork is probably going to work poorly [especially at higher speeds and for bigger bumps].

If you just throw in something that says 10wt, you're probably going way too high compared to stock. For example, a Silkolene Pro RSF 10wt has a viscosity of 47.7 cSt which is triple the viscosity of the stock fork oil for some bikes! I would think this would give very poor results although I'm sure some would try it, give it the parking lot test with the front brake held, feel the heavy damping, and declare they've made an drastic improvement."

from Vstrom Fork Oil change? - ADVrider

I have used heavier 20w-50 oil at a higher level than stock in my forks for about 18,000 miles, after 2000 miles with the original fork oil and one fork seal started to leak. This 2002 600cc cruiser is now worth about $1400 retail, and I do not think better fork springs, cartridge emulators, or even more expensive fork oils are worth it, especially since I rarely go more than 5 mph over the speed limit with it. I am happy with this oil in the forks. You might decide differently if you owned this bike.

My 2008 ZZR600 still has the original fork oil with about 6,000 miles on it. I might eventually get a used back shock from a newer bike, and I plan to use a new fork oil similar to the original fork oil.

If I was using my ZZR600 for track days, it would be best to spend the money to have an expert test the forks and shock and have them make improvements.

For cruisers, people will spend big bucks for 1940s style springer forks with less suspension control than the original forks. It is their money and their risks.
 

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Jeff do you have some sort of degree in oils or just a lot if trial and error? Not trying to flame you just 9 outta 10 posts are about oil from you im just curious

Sent from my LG-E739 using Motorcycle.com Free App
 

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The Indifference Engine
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Some more advice that I found for forks:

"Most folks who stiffen their suspension (either by stiffer springs or by stiffening up the damping) say their bike works better, but unless you do a proper setup and know what you're doing, you're probably making things worse.

If you're just using stock springs (either because they are the right ones or you haven't resprung), then you probably want to keep pretty close to the stock fork oil viscosity. Even with heavier springs, I wouldn't make a drastic change in viscosity - if the springs are 20% stiffer, I'd tend to put in 20% thicker fork oil if I made any change at all. And if I decided to make a fork oil change from stock, I'd first start with fork oil height (air volume) before I'd change fork oil viscosity. Fork oil viscosity would be my last fine-tuning thing.

The fork oil mfg's are notorious for not using consistent viscosity measurements and/or naming their fork oils with misleading names, partly to satisfy buyers who think a bigger number is better.

Mfgs these days generally specify very low-viscosity fork oils and the forks are designed for this - stick a thick oil in there and the fork is probably going to work poorly [especially at higher speeds and for bigger bumps].

If you just throw in something that says 10wt, you're probably going way too high compared to stock. For example, a Silkolene Pro RSF 10wt has a viscosity of 47.7 cSt which is triple the viscosity of the stock fork oil for some bikes! I would think this would give very poor results although I'm sure some would try it, give it the parking lot test with the front brake held, feel the heavy damping, and declare they've made an drastic improvement."

from Vstrom Fork Oil change? - ADVrider

I have used heavier 20w-50 oil at a higher level than stock in my forks for about 18,000 miles, after 2000 miles with the original fork oil and one fork seal started to leak. This 2002 600cc cruiser is now worth about $1400 retail, and I do not think better fork springs, cartridge emulators, or even more expensive fork oils are worth it, especially since I rarely go more than 5 mph over the speed limit with it. I am happy with this oil in the forks. You might decide differently if you owned this bike.

My 2008 ZZR600 still has the original fork oil with about 6,000 miles on it. I might eventually get a used back shock from a newer bike, and I plan to use a new fork oil similar to the original fork oil.

If I was using my ZZR600 for track days, it would be best to spend the money to have an expert test the forks and shock and have them make improvements.

For cruisers, people will spend big bucks for 1940s style springer forks with less suspension control than the original forks. It is their money and their risks.
Your quote contradicts your statement. It suggests not changing viscosity regardless.

Basically, you have nothing.
 

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Discussion Starter #14
"Jeff do you have some sort of degree in oils or just a lot if trial and error? Not trying to flame you just 9 outta 10 posts are about oil from you i'm just curious"

I read a wide range of sources, especially about differences of opinion and there is the most disagreement for oil choice; one person will use Rotella 15w-40 diesel oil in their motorcycle engine until their shifting starts to get worse (including a surprising number of WERA track day riders), and another will use a very expensive oil and change it after every track weekend. My choice is in between the two extremes.

I think that using a high quality fork oil in very low quality cruiser forks is a waste of money, so I decided to try a 20w-50 engine oil in the forks, for my extra body weight on a bike designed for short, light riders, and I am happy with it. This would be a bad choice for track days, but this bike is not designed for riding fast, with its single front disk brake and low quality cheap suspension. I do plan on using a high quality fork oil at the original design weight for my ZZR600 forks, when I have the original fork oil replaced.
 

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"Jeff do you have some sort of degree in oils or just a lot if trial and error? Not trying to flame you just 9 outta 10 posts are about oil from you i'm just curious"

I read a wide range of sources, especially about differences of opinion and there is the most disagreement for oil choice; one person will use Rotella 15w-40 diesel oil in their motorcycle engine until their shifting starts to get worse (including a surprising number of WERA track day riders), and another will use a very expensive oil and change it after every track weekend. My choice is in between the two extremes.

I think that using a high quality fork oil in very low quality cruiser forks is a waste of money, so I decided to try a 20w-50 engine oil in the forks, for my extra body weight on a bike designed for short, light riders, and I am happy with it. This would be a bad choice for track days, but this bike is not designed for riding fast, with its single front disk brake and low quality cheap suspension. I do plan on using a high quality fork oil at the original design weight for my ZZR600 forks, when I have the original fork oil replaced.
For your track bike you mean?
 

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Discussion Starter #16
"For your track bike you mean?"

For engine oil I use a mix of cheaper and more expensive engine oils for both my cruiser and my ZZR600, changed once a year, because after trying several oils, this combination gives me the best feel for both the clutch and the shifting. I am willing to risk that the stock oil additives will not chemically react with each other for a bad result, which has not happened since I started mixing these oils 8 years ago.

For fork oil, my ZZR600 will have new fork oil added at the same time the tires and brake fluid are changed. I am thinking about getting the 10 weight for this brand below, for my 205 pounds:

5609 - Race Tech Ultra Slick Synthetic 5 weight Fork Oil

My cruiser has the thicker engine oil in the forks, and this would be a terrible choice for track days, but it works great for my usual 25 mile rides on public roads at legal speeds.
 

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I'm a month late but I feel the need to add my two cents. Jeff, I'm not going to bash you or call you names because that's not how I operate. However, I strongly disagree with your way of dealing with your suspension issues.

I too work with a limited budget (that's why I have a 22 year old bike)... First, fork oil doesn't cost much more than engine oil, if it costs more at all. Also, most forks use between 1 and 1.5 quarts of oil. Let's assume that you change your fork oil once a year (as we all should but not many people do), it would cost you at the most $12-$13 per year (around here a quart of fork oil costs 6 bucks at Napa). Engine oil costs about the same; so why not use something designed for your forks, as cheap as they may be?

When you're a heavier rider, your suspension issues are two-fold:
a) your springs (on both ends) are too weak to keep your suspension working in its optimal range (that's why we set the sag), and
b) your oil MAY be too thin for your application (notice them emphasis on may).

I'll give you a personal example. My previous bike was a 1994 Yamaha FZR600 with damper rod forks. I rode on the street and track with it for 7 years and thought my forks were fine with the stock 10w oil because I didn't know better (it was my first bike and I weigh 225 pounds). One day looking online, I found catridge emulators from a company other that Race Tech for $35 and decided to give them a try, along with Sonic Springs new fork springs. The original springs were 0.464kg/mm and I needed 1.0kg/mm. The total cost for the operation was around 150 dollars and that included new seals and new lighter fork oil. Yes I said lighter because that's what was recommended for my application after putting the emulators in.

The difference was night and day, and I didn't just test them in a parking lot. The front felt planted, no more pogo stick feeling, no more bottoming out when braking. I was a little skeptical before doing it because I didn't know what the whole was about optimizing your suspension, but after doing it I'm a believer whether you stay on the street or track your bike.

Also, found the valves I used in my FZR; they may fit your bike but I don't know what model you have (I had 38mm forks):
Harley Parts | Aftermarket Harley Davidson Motorcycle and Custom Parts and Accessories | Debrix Cycles - www.debrix.com

If you intend on keeping your bike for any length of time, suspension upgrade is well worth the money; especially if you do the work yourself. And damper rod forks were easy to work on for someone like me who had never done it before.
 

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Discussion Starter #18
My 2002 Honda cruiser is worth about $1000 and I usually ride it 25 miles at a time.
I know stiffer fork springs and cartridge emulators would be better, but I rode and raced bicycles with no suspension other than the air in the tires for years, and I am happy with heavier and more oil in the forks for this bike, for both price and function compared to the stock oil, which became terrible after just a few months when the extremely cheap stock fork springs sagged more.

My 2008 ZZR600 has a better stock suspension, and I plan to have the back shock reworked by a pro, with the front forks getting new 10-weight fork oil and adjustment also added by a pro within the next couple of years, when the engine valve adjustment needs to be checked. Others would just save the money and leave it stock- their choice.
 

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Discussion Starter #19
This guy below came up with a chart for mixing Redline brand fork oil for a variety of weights, if you want to experiment with both fork oil weight and fork oil height:
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http://www.peterverdone.com/archive/files/Red Line Mix Chart.pdf


I found I like my cruiser fork oil a lot thicker and higher than stock. I like the ZZR600 fork oil stock for now. If you disagree, tough shit.
 
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