shortening front springs

[mikedabike64]

I had an A EX 500 ninja, and some of the guys had some success with cutting the springs up front which is essentially was almost like making a heavier Spring.
I see that there was a nice write-up on adding preload, but I was wondering if anybody had any success with shortening the springs in lieu of buying heavier Springs
, I will be doing track days on my bike.
, I thought I would tighten it up first with the preload, and then possibly experiment with the springs,
I know typically depending on your weight heavier springs & emulators are the way to go but Iam on a tight budget. thanks Mike H.

[mania]

I know you said your on a budget but
Best way is new springs with spacers cut to suit.

Rich at Sonic Springs will fix you up for like $89

Preload adjuster caps ( if that is what you meant? )make no difference in my experience unless you have already
sussed out the springs/spacers. Even then you will probably not need them as you will have set the preload for your weight with the spacer & spring rating

Cutting soft stock springs will not make them heavier. It will just have less travel of an already weak spring

[InvisiBill]

The preload adjustment just determines where in the range of the spring the bike will operate. If you're the wrong weight for the springs, preload won't help that.

Note that emulators control the damping, which is separate from the spring rate. You don't need to do both at the same time (though many do to get the most improvement at once).

You can try cutting the springs if they have enough extra length and you're close enough to the originally intended weight. Or just spend the ~$100 and buy the right springs for your weight.

Originally Posted by mania

Cutting soft stock springs will not make them heavier. It will just have less travel of an already weak spring

Actually it will. Think of it as shortening a lever. This lever just happens to be coiled around inside a tube, rather than in a straight line. The longer lever allows the same amount of movement with less force. The shortened spring has less leverage, and so the same amount of force will move it less (it will be stiffer). You do need to be mindful of how much you're cutting off the spring so as not to interfere with the travel though.

[mikedabike64]

Always appreciate the help.

[mgentz]

I run shorter springs with no issues

[mikedabike64]

I also found a set of EX five hundred springs as well, so I will experiment what some combinations and see what I come up with I just want to keep it simple, start with the preload first,

[KawiKid860]

I plan on cutting my springs when I get the chance to restore my 500. 5 inches off is about the max you want to do for the 500 at least, which yields a .76kg/mm spring rate. Racetech recommends .85kg/mm for my weight (now that I'm not a 135lb 16 year old anymore lol) but I figure .76 is close enough for street riding. Anything is better than the stock stuff on the 500...

Also throwing on an 08-12 250 rear shock since it's a direct bolt on, better than the 500 shock (mines like blown out or something anyways) and a bit taller so it'll raise up the rear

[mgentz]

shortening the springs increases the rate but also limits the total travel. you must ensure that the springs will not coil bind before you run out of travel. If this is ok, you can cut down the spring as much as needed and simply increase the preload spacer length.

[choneofakind]

FYI, ex500 springs are 29mm shorter than ex250 springs already. You'll have to account for that with your preload spacers.

Ex250 length+29mm+whatever you cut off the spring

[mikedabike64]

much obliged on that info I could not find the spring rate on the 500 vs the 250 if I were to experiment with the five hundred springs I would probably just drop it in rather than cut it if its short already and give it a whirl that way,

[choneofakind]

EX500 springs are 0.585. Racetech says I need 0.64, so cutting might be an option after I do some math.

http://faq.ninja250.org/wiki/EX500_springs_option

[InvisiBill]

Originally Posted by KawiKid860

Also throwing on an 08-12 250 rear shock since it's a direct bolt on, better than the 500 shock (mines like blown out or something anyways) and a bit taller so it'll raise up the rear

The stock EX500 spring is 300#, good for a ~135lb rider. The NewGen spring is 520# and good for a ~235lb rider. The SV650 and PreGen shocks have 430-440# springs, good for a ~195lb rider. If you're not a big guy, you might be better off swapping a PreGen spring on a stock shock or putting in the SV shock, rather than going with the NewGen shock. I'm not sure if it was just settled when I first installed it or what, but the NewGen shock seems to be only a tiny bit longer than stock.

Details at http://www.ex-500.com/wiki/index.php...ear_Suspension.

Originally Posted by mikedabike64

much obliged on that info I could not find the spring rate on the 500 vs the 250 if I were to experiment with the five hundred springs I would probably just drop it in rather than cut it if its short already and give it a whirl that way,

According to RaceTech's calculator, the EX500's original spring rate is good for a 50lb rider on a NewGen. It's 30% stiffer than stock, but still quite low. Even for just a 160lb rider, they recommend going up to a .75kg/mm spring. If you have some, you might as well try them, but I wouldn't go out of my way to get them since they're only marginally better.

Originally Posted by choneofakind

FYI, ex500 springs are 29mm shorter than ex250 springs already.

And oddly enough, the 500's forks are actually listed as 5.1" of travel while the 250 is only listed as 4.7". (When I decided to get the Vrossi wheels, I looked into just swapping over a complete set of 250 forks to get the fender too.)