Front Suspension Upgrade Questions

[FinalImpact]

I've done some reading on cartridge emulators and their huge advantages over fixed damping rods. It seems that at my weight of 175, my money would be best spent on the Racetech emulators, some shims to get the sag right, and some fresh 10 or 15 wt oil. I will leave the springs stock for now. As I understand simply adding the emulators will reduce front end dive significantly as well as make the bike much more compliant over bumps in the road. The more I read about the emulators, the more they make sense. Damping rods are so old tech!

So what type of riding do you do? if its not to hammer down but just sport action I bet you might be happy doing what you describe here.

The oil wt will be the rebound control so it might take a couple of tries but beyond that - if you don't want the hassle of shopping for used forks and all that, it should work. Later you can always pop the caps and change springs if you like but I suspect this will get you 70% of what you want.

 

[outasight20]

I do mostly commuting on the highway but occasionally will get pretty aggressive in the twisties. There's a lot of crappy roads around here so I'm mostly looking to improve the way the front end handles big bumps and ruts in the road, as well as reduce dive upon heavy braking. As far as control in the corners, on smooth roads I find the stock suspension just fine. And I've scraped the pegs a few times doing over twice the speed limit through some nice bends.

 

[ozgurakman]

I want to just reduce diving but not want to change any setting on front. what should I do?

 

[ozgurakman]

---- sorry for same reply. ----

 

[Carlos840]

I want to just reduce diving but not want to change any setting on front. what should I do?

You can't reduce diving without changing anything.

I only changed the oil to 10w and that already made a pretty noticeable difference. I would definitely recommend doing so.

 

[DeepBlueRider]

I want to just reduce diving but not want to change any setting on front. what should I do?

I've already replied in another thread. Just for your conviniance:

Depends.

Usually main reason for bike STARTED to diving is because fork oil got old and it's not slowing down suspension enough. So in that case replacing fork oil will be enough. I would give a try 10W oil (I'm using 15W but it seems little on heavy side for me).

However if it's not fork oil, it might be your fork springs are not adjusted to your weight. OEM FZ6 (at least in 2008) are two zone springs. They are initially very soft and then become very hard (It's not linear progressive spring).

My suspension guy recommended me to put 0.85 (IIRC) springs in mine and made custom preload spacers from PVC pipe.

I weight 160lbs.

How much do you weight ?

Check RaceTech Suspension website for idea what to use for your weight.

Back again - if you haven't changed fork oil for over a year, you might try putting new 10W or 15W (actually 15W with stock springs might work) fork oil and it should significantly improve on diving.

 

[Carlos840]

I've already replied in another thread. Just for your conviniance:

Depends.

Usually main reason for bike STARTED to diving is because fork oil got old and it's not slowing down suspension enough. So in that case replacing fork oil will be enough. I would give a try 10W oil (I'm using 15W but it seems little on heavy side for me).

However if it's not fork oil, it might be your fork springs are not adjusted to your weight. OEM FZ6 (at least in 2008) are two zone springs. They are initially very soft and then become very hard (It's not linear progressive spring).

My suspension guy recommended me to put 0.85 (IIRC) springs in mine and made custom preload spacers from PVC pipe.

I weight 160lbs.

How much do you weight ?

Check RaceTech Suspension website for idea what to use for your weight.

Back again - if you haven't changed fork oil for over a year, you might try putting new 10W or 15W (actually 15W with stock springs might work) fork oil and it should significantly improve on diving.

I weight 176 lbs without gear, have stock springs, and i could already tell a massive difference going from the 4 years old stock watery crap they call oil to fresh synthetic 10w.

I would think going straight to 15w would be a pretty dramatic change and it might be worth starting with 10w to get an idea of what it feels like.

 

[motojoe122]

I weight 176 lbs without gear, have stock springs, and i could already tell a massive difference going from the 4 years old stock watery crap they call oil to fresh synthetic 10w.

I would think going straight to 15w would be a pretty dramatic change and it might be worth starting with 10w to get an idea of what it feels like.

After 4 years I bet that oil smelled like roses
I did the spring and oil swap within the first year of ownership.....I'm pretty sure I threw up in my mouth that day
Later came the R6S fork swap.

 

[DeepBlueRider]

I would think going straight to 15w would be a pretty dramatic change and it might be worth starting with 10w to get an idea of what it feels like.

You were right Carlos. I've just changed my old (15W) oil to 15w and it feels too stiff. Former oil would have to be really degraded because change is dramatic. I will give it some time, but probably will change with 10W some tome soon. I've used Maxima 15W.

On the other hand racetech.com recommends 15W on their website. They usually have very good guidelines for tuning suspension tuning so it might be just personal preference.

 

[Carlos840]

You were right Carlos. I've just changed my old (15W) oil to 15w and it feels too stiff. Former oil would have to be really degraded because change is dramatic. I will give it some time, but probably will change with 10W some tome soon. I've used Maxima 15W.

On the other hand racetech.com recommends 15W on their website. They usually have very good guidelines for tuning suspension tuning so it might be just personal preference.

I think there is some personal preference, but i also remember a thread where someone pretty much proved by A plus B that the suspension was not designed to work with such a heavy grade of oil.
Something to do with the size of the holes the oil had to travel through being to small to work properly with thicker oil.
I also watched a lot of Dave Moss's suspension videos and he says the same thing, that going to a really thick oil is only a band aid and not a real solution.
That while helping your compression, you will screw up your rebound...

All that made me decide to try 10W first and it really worked out great for me!

How long was your oil in there for before you changed it? And did you change to the same brand?
Apparently every brand has a different idea of what 15W means and they all have different viscosity.

 

[ped]

I think there is some personal preference, but i also remember a thread where someone pretty much proved by A plus B that the suspension was not designed to work with such a heavy grade of oil.
Something to do with the size of the holes the oil had to travel through being to small to work properly with thicker oil.
I also watched a lot of Dave Moss's suspension videos and he says the same thing, that going to a really thick oil is only a band aid and not a real solution.
That while helping your compression, you will screw up your rebound...

All that made me decide to try 10W first and it really worked out great for me!

How long was your oil in there for before you changed it? And did you change to the same brand?
Apparently every brand has a different idea of what 15W means and they all have different viscosity.

It's not...that's the problem with damper rod forks. That's what the racetech emulators are for.

I've ran 5w, 10w, 15w, 20w, 25w, 30w

25w is just right unless it's really hot and you're doing track riding in which 30w is better. (I should say this if for aggressive riding/trackdays)

Racetech is usually pretty wrong about things FYI. They don't actually go out and get a model of every bike and go through a plethora of tests to find the best tune possible. They're just giving a base guideline. 15w is a generic answer for all damper rod bikes. It's hard to know who to listen to and why if you don't understand what you're looking for in the first place.

 

[ped]

When you put racetech emulators in the bike the low speed compression valves are ported bigger than stock and that's when you need the heavier oil. If for stock valving 20w is pretty good all year round.

What you're looking for in the hydraulic reaction of the bike is a single rebound stroke. When you bounce the front end it should rebound and then settle down into the compression stroke and stop. any more movement than that and you're not getting enough dampening.

How hard you bounce and what time of day you bounce a bike makes a big difference. You gotta put your back into it....don't be shy. And do it after 20 minutes of riding to get the suspension up to operating temp. In the morning it might be too stiff and the afternoon it might be to soft. That's why having R6 forks are better.

If I were still riding my FZ6 at the track I would weld one of the two rebound holes and one of the emulators compression holes then run 10-12.5w (you can mix oils to make custom weights BTW) because the thinner oil has less thermal variation on viscosity.

another thing that one could do that would work quite well is drill out the rebound valves on one fork and the compression valves in the other. Then mix and match oil weights to dial in each side separately. That's how newer R1's are setup from the factory. The only caveat is you'd likely need to get really heavy oils in there (or weld half the valves and use ~15w +/- 5). This would give you completely separate rebound and compression adjustments and even nullify the need for emulators in a lot of cases if you wanna stay soft on the compression stroke for easy riding.

 

[ozgurakman]

I did the spring and oil swap within the first year of ownership.....I'm pretty sure I threw up in my mouth that day
Later came the R6S fork swap.

I can't understand your sentece which is "I threw up in my mouth that day"...
so are you not satisfied when you changed springs and oil? and wat was your tune-how much is your weight?

how about r6s forks? are they fine for sport touring under heavy load with passenger?

 

[ozgurakman]

I've already replied in another thread. Just for your conviniance:

Depends.

Usually main reason for bike STARTED to diving is because fork oil got old and it's not slowing down suspension enough. So in that case replacing fork oil will be enough. I would give a try 10W oil (I'm using 15W but it seems little on heavy side for me).

However if it's not fork oil, it might be your fork springs are not adjusted to your weight. OEM FZ6 (at least in 2008) are two zone springs. They are initially very soft and then become very hard (It's not linear progressive spring).

My suspension guy recommended me to put 0.85 (IIRC) springs in mine and made custom preload spacers from PVC pipe.

I weight 160lbs.

How much do you weight ?

Check RaceTech Suspension website for idea what to use for your weight.

Back again - if you haven't changed fork oil for over a year, you might try putting new 10W or 15W (actually 15W with stock springs might work) fork oil and it should significantly improve on diving.

my weight is 75 kgs, it means ~165 lbs without gears. with gears I think + 13lbs. and I have 50 liters luggage on my Fazer.

 

[Carlos840]

I can't understand your sentece which is "I threw up in my mouth that day"...
so are you not satisfied when you changed springs and oil? and wat was your tune-how much is your weight?

how about r6s forks? are they fine for sport touring under heavy load with passenger?

The old fork oil, at least the stock one, has a tendency to smell like dead composted fish, it's really is nasty business draining them...

I weight pretty much the same weight as you, 79 kg without gear, and for me changing the oil to 10W was enough for the moment, and i don't feel the need to change springs as much as i did before.
I probably will still do it at some point just to see what the deal is, but the thicker oil has pretty much made dive under breaking pretty minimal, which was my main issue with the stock fork.

If you don't want to spend much, start with an oil change, you will be surprised by the result. I used motul factory line 10w, fully synthetic, very happy with it.

 

[FinalImpact]

I'd be hesitant to mod the forks in manor to use the left for compression and right for rebound. The axle, hub, forks, triple and lack any brace (fender doesn't count) and would induce too much flex where it shouldn't be. I wouldn't do it myself w/out a solid brace between the forks.

I love my R6 forks and how they respond. >> http://www.600riders.com/forum/fz6-mods/42817-best-investment-ever-r6-forks-rides-so-nice.html

Coupled with a revalved R1 shock, bike is pretty fun as is. I do wish I had some high-speed valving adjustment for the "shocker" of rough roads, but still very confident and predictable!

 

[ped]

Nope it sure doesn't. Again the R1 and motogp bikes work the same way and for many years racers have been mix-matching springs and oils. When the forks are held by both upper and lower triples all hydraulic and spring forces act as one unit.

 

[DeepBlueRider]

I also watched a lot of Dave Moss's suspension videos and he says the same thing, that going to a really thick oil is only a band aid

That's true - it's only patch up job.

How long was your oil in there for before you changed it? And did you change to the same brand?

It lasted something around 5 months. 2 trackdays, everyday commute, weekend riding and that damn 20mile off-road bashing. I bet that off-road stretch I've ended up in caused most of oil degradation.

I've replaced it with same Maxima 15W fork oil.

 

[DeepBlueRider]

my weight is 75 kgs, it means ~165 lbs without gears. with gears I think + 13lbs. and I have 50 liters luggage on my Fazer.

So you weight more/less the same as I do.

I think changing springs to 0.85 and putting new 10W oil would greatly improve your handling.

Can I ask why don't you want to change front fork settings ? You just don't want to mess with factory setup or is it something else ?

 

[ozgurakman]

So you weight more/less the same as I do.

I think changing springs to 0.85 and putting new 10W oil would greatly improve your handling.

Can I ask why don't you want to change front fork settings ? You just don't want to mess with factory setup or is it something else ?

I'm a perfectionist person, I want fine handling both low and high speeds. I know it's not possible if I change only suspension oil
I want to gain more compression resistance without losing rebound latency, so if I change both susp oil and springs will I gain my wants?