New fork springs or replace with R6 forks?

[mdfb42]

I was hoping to get some advice from people who have updated their fork springs or replaced their forks with some R6 forks. What do oyu think is the better option for a stiffer front end without feeling every bump in the road (contradicting I know). Obviously fork springs are cheaper and easier to find at a good price, but will it be the same quality? And how much do the R6 forks actually lower the front end? I heard some say a lot and some say not at all.

I have a '09 and am currently looking at Sonic Springs but want to know which way is the best way to go

 

[FinalImpact]

Go ride a couple other sport bikes and you will find that you do feel the road and its a normal to have input from below telling you of the conditions.

Granted the R6 is about a 100lbs lighter than Z its when you look at the spring rates you see progressive spring falls on its face.

The rates for the front are:
Stock FZ6 progressive rate of:
Spring rate K1: __________7.40 N/mm (42.25 lb/in) (0.75 kgf/mm)
Spring rate K2: __________11.80 N/mm (67.38 lb/in) (1.20 kgf/mm)
Meaning it starts as one rate and gets firmer the more its compressed. FYI: The back is a fixed rate.


R6 Spring rate K1: ___________8.3 N/mm (46.49 lb/in) (0.83 kg/mm)

As you may have noticed the first 2.5" of travel on the FZ are consumed quickly. In my case simply sitting on the bike uses 1.5" of it. Rocking it with the brake applied uses about 3" of the 5".

If I were to do the minimal for a 200lb rider and gear it'd be the springs at (0.9 kgf/mm) as the stock R6 @ 0.83 kg/mm with a linear rate seem to be pretty good.

More details about what I learned along the way. . .
http://www.600riders.com/forum/fz6-general-discussion/36842-somethin-black.html#post461560

 

[mdfb42]

Go ride a couple other sport bikes and you will find that you do feel the road and its a normal to have input from below telling you of the conditions.

Granted the R6 is about a 100lbs lighter than Z its when you look at the spring rates you see progressive spring falls on its face.

The rates for the front are:
Stock FZ6 progressive rate of:
Spring rate K1: __________7.40 N/mm (42.25 lb/in) (0.75 kgf/mm)
Spring rate K2: __________11.80 N/mm (67.38 lb/in) (1.20 kgf/mm)
Meaning it starts as one rate and gets firmer the more its compressed. FYI: The back is a fixed rate.


R6 Spring rate K1: ___________8.3 N/mm (46.49 lb/in) (0.83 kg/mm)

As you may have noticed the first 2.5" of travel on the FZ are consumed quickly. In my case simply sitting on the bike uses 1.5" of it. Rocking it with the brake applied uses about 3" of the 5".

If I were to do the minimal for a 200lb rider and gear it'd be the springs at (0.9 kgf/mm) as the stock R6 @ 0.83 kg/mm with a linear rate seem to be pretty good.

More details about what I learned along the way. . .
http://www.600riders.com/forum/fz6-general-discussion/36842-somethin-black.html#post461560

THANKS! That is a perfect answer IMO. My spring rate is technically .9 to .95 for body weight, etc. so all I have left is the debate between getting .85 and .9 springs because I want a little softer than what I am rated at but when riding 2-up I don't want to soft of springs...granted my girlfriend is a whopping 98lbs.

 

[iSteve]

You should go with recommend spring and use the oil weight to adjust how smooth the ride is. I ended up with .95 and 5wt oil. This lets the springs react quickly. A lot of people will use too heavy of a oil that slows the compression and makes for a harsh ride on rough roads.

 

[mdfb42]

You should go with recommend spring and use the oil weight to adjust how smooth the ride is. I ended up with .95 and 5wt oil. This lets the springs react quickly. A lot of people will use too heavy of a oil that slows the compression and makes for a harsh ride on rough roads.

Great Idea. Do you mind me asking your body weight, etc. so I know if I want to go .90 or .95

 

[pascal1973]

I first installed Hyperpro progressive springs, with 15W oil, that changed the ride 100%. Few months ago, i found a used R6 fork....needless to say i bought it, i use stock springs, 15W oil . I have to say the R6 forks made the bike handle easier, and a lot more fun to ride. I say mod to R6 front if you can find a nice set of legs!

 

[mdfb42]

I first installed Hyperpro progressive springs, with 15W oil, that changed the ride 100%. Few months ago, i found a used R6 fork....needless to say i bought it, i use stock springs, 15W oil . I have to say the R6 forks made the bike handle easier, and a lot more fun to ride. I say mod to R6 front if you can find a nice set of legs!

I was always told that progressive springs are pretty much pointless on sport bikes because of the limited amount of movement that normally occurs. With that said, yes I know they have progressive springs standard. I am just passing along what I was told

 

[iSteve]

I know progressive springs work great in dirt bikes. I to was under the impression that they don't do much with short travel street bikes.

With the R6 forks aren't they suppose to use 0wt oil. I know most racer mechanics use 0wt because it doesn't change with heat and they use the damper adjustments to set fork action. This may be just with newer forks.

 

[FinalImpact]

I know progressive springs work great in dirt bikes. I to was under the impression that they don't do much with short travel street bikes.

With the R6 forks aren't they suppose to use 0wt oil. I know most racer mechanics use 0wt because it doesn't change with heat and they use the damper adjustments to set fork action. This may be just with newer forks.

Stock on the 03-04 R6 is 5wt. Others may vary I never looked. I bought used forks (3400miles) which I cycled some fresh oil though to clean them out. Mind you I was about to do a spring swap on the FZ so i had 10wt. I used that but may dump it once I run it abit longer just to see what it does as it's NBD to pull the forks.

Yes, progressive springs have their place so these are either loosing strength (starting rate of 0.77kg/mm (42.25 lb/in)) or the valving simply sucks (or both). I can easily compress stock springs roughly 3" rocking the bike with the brake applied. Because yam'rs equipped the R6 with fixed rate springs and the value isn't much greater (0.83 kg/mm, 46.49 lb/in) than the FZ, I'm going to step out on the limb and say the valving is what's hurting it the most. Oil and emulators are likely a good combo for the stock parts.

 

[Spideyrex]

I think you should also factor in the type of riding you will do. I went with Hyperpros and 15wt oil and it feels great! But if you will be doing more track days or very spirited riding, an R6 fork is probably the way to go. For my style, wt, and budget the Hyperpros were the right fix. It firmed up the front, got rid of the stock wallowing in the corners, yet still kept things very smooth on rough roads.

 

[iSteve]

I guess we can all agree on one thing, the stock spring is too soft.

 

[red_rock_beetle]

I guess we can all agree on one thing, the stock spring is too soft.

thats ok, they make up for it with the seat

 

[Hellgate]

R6 forks, hands down. Ive got a detailed thread on it.

Sent from my LG-P925 using Tapatalk

 

[mdfb42]

I think you should also factor in the type of riding you will do. I went with Hyperpros and 15wt oil and it feels great! But if you will be doing more track days or very spirited riding, an R6 fork is probably the way to go. For my style, wt, and budget the Hyperpros were the right fix. It firmed up the front, got rid of the stock wallowing in the corners, yet still kept things very smooth on rough roads.

you mind me asking your body weight and strength of springs you went with? Because I won't be going to the track, I will be on rough back roads alot considering the small town I am in, but like you said, I don't want the wallowing in the corners.

 

[motojoe122]

I just swapped my springs and oil. Im 190 w/o gear, so 220 w/ gear.

I went with Racetech .95 springs and 15w oil. Huge difference than stock.

 

[mdfb42]

I just swapped my springs and oil. Im 190 w/o gear, so 220 w/ gear.

I went with Racetech .95 springs and 15w oil. Huge difference than stock.

Interesting. Do you do any riding on rough roads or many well paved and highways. I'm 190 w/o gear and was leaning towards .90 w/ 5wt but now might find a happy medium at .90 15w

 

[motojoe122]

Interesting. Do you do any riding on rough roads or many well paved and highways. I'm 190 w/o gear and was leaning towards .90 w/ 5wt but now might find a happy medium at .90 15w

Well, I do live in the DEEP SOUTH of Jersey

But, yeah, the roads out here are terrible! Now, instead of the front end knocking your teeth out its more of a slight thud.....waaaaayy better:thumbup:

EDIT: You might even try .95's with 10w oil.

 

[mdfb42]

Well, I do live in the DEEP SOUTH of Jersey

But, yeah, the roads out here are terrible! Now, instead of the front end knocking your teeth out its more of a slight thud.....waaaaayy better:thumbup:

EDIT: You might even try .95's with 10w oil.

I believe that will be the answer. Thanks!

 

[motojoe122]

Glad to be of help:thumbup:

 

[Hellgate]

Here's my thread on the R6 fork install.

http://www.600riders.com/forum/fz6-mods/7411-r6-fork-mod-completed.html