18’ 450F spring rate (50 kg / 5.9kg)?

[Hatchers]

I just bought this bike and am trying to figure out what it came with. It appears the shock spring is 5.8 NM, while the fork is a 50. This is a heavy spring rate and should work for a slow vet like myself, 210 dry body weight. Am I correct?

[gedakbx]

possibly but they may be a little soft for you my son is a fast 160 lbs pro we are running 4.85 fork springs and 5.5 rear spring. Look it up at   Q-SPRINGS .COM

[HORSEPOWER35]

7 hours ago, Hatchers said:

 

I just bought this bike and am trying to figure out what it came with. It appears the shock spring is 5.8 NM, while the fork is a 50. This is a heavy spring rate and should work for a slow vet like myself, 210 dry body weight. Am I correct?

 

No, will not work.  At 210 you will need likely 2 rates stiffer.  Probably 6.3 kg.  Being slow has nothing to do with your shock spring rate.  It is determined by weight.  Achieving proper static and rider sag is what you're after.  The stock fork spring @ .50 kg will be fine.

[mikedabike]

You should be close.  See if you can get the correct sag.  Remember Yamaha measures NM while aftermarket is all KG.  5.8NM is equivalent to 5.9KG

I am a taller and heavier guy and the forks springs are usually OK for me but I need stiffer on the rear

[gmtech16450yz (motobark)]

On 2/10/2019 at 12:36 PM, Hatchers said:

 

I just bought this bike and am trying to figure out what it came with. It appears the shock spring is 5.8 NM, while the fork is a 50. This is a heavy spring rate and should work for a slow vet like myself, 210 dry body weight. Am I correct?

 

I just wrote up some info about the '18 YZ450 suspension that might help you or others...

Remember on springs and sag it makes a big difference WHERE you ride ON the bike. Yeah, weight matters more than riding ability, but body position makes a big difference too. My buddy at 225 lbs felt my .51 stock fork springs on my '18 YZ450 (book says .50 but I believe they're closer to .51) were way too stiff for him even.

[Hatchers]

I had to use a 6.3 race tech spring I had for my 450FX, this 6.3 spring is pretty short. While measuring race sag, I had to use all the shock body threads at the lower end to get sag about 103 in street clothes, not sure how much more I can go before I’m relying on just 1 or 2 complete thread turns, hope to test the bike soon

[MxGringo]

I had to use a 6.3 race tech spring I had for my 450FX, this 6.3 spring is pretty short. While measuring race sag, I had to use all the shock body threads at the lower end to get sag about 103 in street clothes, not sure how much more I can go before I’m relying on just 1 or 2 complete thread turns, hope to test the bike soon

Std length of the shock spring is 280mm. I tried a 260mm long but I couldn't preload it enough.
Only spring supplier I could find with correct length springs was q-springs 275 mm

[mx369]

1. Im 6 2 weigh 210   The stock Yamaha springs rates are the best suspension I have EVER rode.  7mm up on forks and 105 sag.   Ive had Enzo, Factory Cpnnection and pro action on my YZs before.   The stock is better that any Iv had!!!!!!!!!!
2.