Which fork springs?

[JZS 600]

I'm due an overhaul on linkages and bearings and was just considering changing fork springs at the same time.....


Anyone have any recommendations?


New fork springs and 10W/15W oil? Just change the oil?


It's an 02 bike and I'm 90 Kgs.


Cheers!

[wezdavo]

I have just done the same.. Havent had a chance to ride it yet though!
I bought Wilbers springs from revs suspension and used 10w oil with 135mm air gap..
Was going to give it a go today but as i have put braided lines on the front i also deciced to clean and rebuild the rear caliper then found it needs new pads  ..
They should be here tomorrow so i might get to ride it to test out the forks...

[unfazed]

I used Hagon progressive with their recommended air gap and standard fork oil.
Adjusted the sag to 23mm and all is fine.
 

[wezdavo]

I used Hagon progressive with their recommended air gap and standard fork oil.
Adjusted the sag to 23mm and all is fine.

What is the rider sag with the Hagon setup??

[JZS 600]

Progressive or linear,,, clue me up!

[JZS 600]

Found this:

So which are actually best?[/b][/font][/font][/color]
[/color][/size]
[/color][/size]Spring Definitions -
[/color][/size]
[/color][/size] [/size]Linear Rate -[/b] also known as straight rate or constant rate springs, are were the entire spring is wound at the same pitch, therefore every kg of force has the same effect on the spring throughout its length. For example, if it takes 25kg of force to compress the spring one inch it will take another 25kg (50kg in total) to compress it the second inch and so on until the end of the travel. Progressive Rate -[/b] are wound progressively from a finer pitch at one end to a coarser pitch at the other, therefore having a rising rate resistance to compression. For example, a 15kg to 25kg progressive spring rate will take 15kg of force to compress the spring one inch, then an additional 17kg of force the next inch and so on until the end of the travel, the last inch takes an additional 25kg to compress it .[/font][/size][/size]
[/color][/size] [/size]
		[/color][/size]The Evidence -[/color][/size]The pro progressive spring people will advocate that you are getting the best of both worlds, you'll be getting a spring that can be soft enough at the start of travel to absorb small road bumps and provide a more 'comfortable' ride, yet still offering the firmness at the end of the travel to handle the big bumps and potholes, major loading under braking and preventing bottoming out. Progressive fork springs are very popular with cruisers and sportstourers.[/color][/size]So why then do the pro linear rate people always say that straight rate springs are better? What's the problem with progressive rate springs? [/color][/size]The first problem is that sportsbikes and racing bikes simply do not have enough suspension travel to take advantage of the progressive rates. The initial softer part of the spring just gets used up straight away leaving a limited amount of travel for the stiffer portion to deal with, resulting in less compliance and less traction. The second problem is that damping rates need to be matched to the spring rates, in particular rebound damping, with progressive rate springs this is impossible. Damping is always a bit of a compromise and adding progressive springs to the mix just makes the job so much more difficult.[/color][/size]The Conclusion -[/color][/size]For sportsbikes and racing bikes virtually all suspension tuners will recommend linear springs, but if you have cruiser or tourer then progressive springs may be the perfect option.[/color][/size]So which are actually best was the original question. You really need to make your own judgement based on your type of bike and what you want from the suspension. This article is only a guide to help you make an informed decision, there is no definitive answer!![/color][/size] [/color][/size]Er, confused.com    [/color]

[/size]

[kebab19]

As a serial suspension modder, IMO Linear springs matched to your weight are usually the way to go, unless you want soft, mushier suspension i.e. comfort over cornering (progressives).

The 600's standard springs are dual rate (progressive springs) and too light for anyone over 8 stone. A pair of 0.85kg/mm or 0.90 kg/mm linear springs would do the job better, along with new fork oil. You can usually get 2nd hand linear springs off ebay if you widen your search to cover bikes with 41mm diameter forks & re-cut the spring spacer to size.

The internal damper rods are the other restriction to the Fazer 600's forks and cartridge fork emulators are the only way round this, limitations explained below:
http://www.racetech.com/articles/CartridgeForks.htm

My fork mod:
http://foc-u.co.uk/index.php/topic,71.0.html
involved fitting Race Tech emulators (ordered from PDQ) that replicated cartridge fork action and therefore gave me adjustable compression and rebound damping, frankly the best standard front fork setup you can have for the FZS600.  Its a popular conversion for other bikes with damper-rod forks, such as the SV650. BUT the mod is permanent unless you get your hands on another pair of damper rods and it is NOT cheap.

[JZS 600]

Thanks Kebab, I'm coming round to the idea that Linear springs will be better for me as I'm not much of a late braker, pretty smooth round the bends.
 
Found the bottom of the springs the other day when I rode (very gently) off a kerb where the bike was parked and felt a "clunk" through the bars, very off putting!
 
Is there much difference bewtween Hagon, Hyperpro, Wilbur and WP or are they pretty much the same thing
 
Cheers,

[wezdavo]

My rear brake pads came today so as was able to go for a ride to try out my forks...

I bought wilbers springs from Revs after reading a previous post on here.

The thing is, when i rang revs and talked to john, i just said i needed something doing with the front end and he recomended Wilbers springs... He asked my weight and what type of riding i do..
Because he had asked about my weight i thought he must be matching me up with linears..

When i opened the box i found out i had been giving progressive, then after looking at the Wilbers website found they only do progressive for the fzs 600..
.
The progresive part of the spring is very small, about 50mm where as the standard yam one is more than double that..

I went ahead and fitted them anyway and i am pleased i did, there f***ing great.

The feedback through the bars  is very good. You can really feel the front end pushing down searching for grip, it feels much more agile when you flick it over and the front end dive when has completely gone.

These springs really suit my riding style,i didnt need linears after all!

Perfect for a road going bike imo
 

[Jbizzle]

Apologies for dragging up and old post, is there any chance you would have a part number for the wilbers you purchased? 


Thanks,


James

My rear brake pads came today so as was able to go for a ride to try out my forks...

I bought wilbers springs from Revs after reading a previous post on here.

The thing is, when i rang revs and talked to john, i just said i needed something doing with the front end and he recomended Wilbers springs... He asked my weight and what type of riding i do..
Because he had asked about my weight i thought he must be matching me up with linears..

When i opened the box i found out i had been giving progressive, then after looking at the Wilbers website found they only do progressive for the fzs 600..
.
The progresive part of the spring is very small, about 50mm where as the standard yam one is more than double that..

I went ahead and fitted them anyway and i am pleased i did, there f***ing great.

The feedback through the bars  is very good. You can really feel the front end pushing down searching for grip, it feels much more agile when you flick it over and the front end dive when has completely gone.

These springs really suit my riding style,i didnt need linears after all!

Perfect for a road going bike imo

[Grayo]

Here you go.    https://www.wilbers-shop.de/en/Motorcycle/Yamaha/FZS-600-Fazer-RJ02-wilbers-4/Wilbers-Fork-Spring-Zero-friction-progressive.html?cur=1?manufacturer=90v40bd08f64cf352173769a2f312731&year=2003&catname=4bd1558943f8720eb7a51f3debac61ec

[Jbizzle]

Thanks Mate

Here you go.    https://www.wilbers-shop.de/en/Motorcycle/Yamaha/FZS-600-Fazer-RJ02-wilbers-4/Wilbers-Fork-Spring-Zero-friction-progressive.html?cur=1?manufacturer=90v40bd08f64cf352173769a2f312731&year=2003&catname=4bd1558943f8720eb7a51f3debac61ec

[Jbizzle]

Hi all,


So I purchased the Wilbers. Very exciting. Fitted them in the garage and during my pre-ride check i have seen a screw in my rear tyre! Gutted!


Need to get it plugged before i can take the bike out for a spin and find out what sort of difference they make.


Interesting to see they have a smaller amount of tightly coiled winding at the top. I guess the material is stronger to produce a stiffer front end? 

[focced_off]

Why do the 2 Springs look quite different (pictured above)? - Their closely coiled sections are far from 'even', with the Springs side by side - is there good reason for this?

[Jbizzle]

Why do the 2 Springs look quite different (pictured above)? - Their closely coiled sections are far from 'even', with the Springs side by side - is there good reason for this?

Hi Focced_Off,


The shinier one on the left is the new one, and  the one on the right is the original.


Interesting to see more tight coiling on the old one eh? I'm guessing the material of the new one provides extra firmness, but it didn't seem that different to me, when i was handling it, will be interesting to see what its like on the road.