fork / shock spring replacement


6 replies to this topic
  • davemo94

Posted September 28, 2006 - 10:28 AM

#1

Hi all, I'm planning to replace the fork & shock springs and I'm hoping to benefit from the collective wisdom of this awesome forum :thumbsup:

I just got the bike 1 month ago, '06 WR450F purchased new. I weigh about 235 lbs. without gear, 6'-4" tall.

Any advice or information on setups that have worked for others of similar weight / riding would be greatly appreciated!

For budget reasons, I'd like to just replace the springs for now, and put off any re-valving, etc. until next year (over the winter). My main concern with the suspension is bottoming resistance supporting my heft on jump landings. I prefer trails / woods riding, but will probably do just as much (more unfortunately) on motocross tracks because that's what all my riding buddies are into.

Will just doing the springs provide the biggest bang for the buck? How much more improvement will revalving provide? Will a heavier than stock oil weight in the forks make much difference?

Can I just replace the fork springs without replacing the fork oil? I read some other posts about replacing the fork oil and it sounds like more of a project than I want right now. Is any oil volume lost in removing the springs that will need to be replaced? Is there any benefit to adding more oil to the forks?

Any recommendations on Race-Tech springs vs. MX-Tech? The websites for each recommend slightly different spring rates for my weight. MX-tech is local for me so I'd probably use them for any future valving, etc. Anybody know why the TT-store doesn't offer any MX-tech products?

Sorry for the long post.

Thanks!

  • bg10459

Posted September 28, 2006 - 10:48 AM

#2

Will just doing the springs provide the biggest bang for the buck?

Bang for the buck is hard to quantify, but IMO, changing springs only is better than re-valving only. If you're not a top level rider you may not appreciate a re-valved suspension.

How much more improvement will revalving provide?

I'm a high C rider and I only re-sprung, front and rear. As I said, I'm not sure I could appreciate a re-valved suspension just yet.

Will a heavier than stock oil weight in the forks make much difference?

Not sure, but I think it will shift your clicker settings as it moves slower though the valves.

Can I just replace the fork springs without replacing the fork oil? I read some other posts about replacing the fork oil and it sounds like more of a project than I want right now. Is any oil volume lost in removing the springs that will need to be replaced?

You can, but I don't see why you would. It's pretty easy to change the oil once the fork caps are off. The oil volume lost for a spring only change will be negligable, but you should re-set your levels anyway.

Is there any benefit to adding more oil to the forks?

Yes. Higher oil levels are typically used to provide greater bottoming resistance. However, I believe you will experience more initial travel harshness. Heavier springs will allow lower oil heights while maintaining bottoming resistance.

Any recommendations on Race-Tech springs vs. MX-Tech?

Most all springs are manufactured by the same few companies, so it doesn't really matter where you get them. Spring rate recommendations will be different. IMO, Racetech rates are a little soft, so you may want to go one size heavier than they say.

  • clark4131

Posted September 28, 2006 - 10:56 AM

#3

I'm in the same weight range as you and went with .48 fork springs and a 5.8 shock spring out back, all from RaceTech. You may want to go with a 6.0 shock spring. My combination gave me a drastic improvement over stock. When replacing the fork springs, it's HIGHLY advisable to do the oil as well. The springs are immersed in it, so you will lose some during replacement anyway. I went with a bit heavier oil, around 7.5 weight, and raised the level just a bit, and I know that aided in the improvement as well. Doing the fork oil really only ads about 2 steps to the process, so it's not a big deal. You'll just need some type of device to measure the level properly. I used the tool from Motion Pro with the ring, dipstick and syringe, which made it a breeze. BTW, the spring rate calculators from both sites are notorious for coming up light on the spring rate. It's been shown that you should up their given rate by at least one selection...SC

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  • Alley Cat

Posted September 28, 2006 - 05:29 PM

#4

6.0 shock spring and .50 fork springs for you mate, that's what I'm running for same weight.

  • davegod

Posted September 28, 2006 - 05:52 PM

#5

i have an 05 wr450 and i weigh about 265 at 6' 2".i got my springs from jeremy at mx-tech.he was very helpful in selecting my springs and answered many set-up questions on multiple phone calls.it's really nice when you can talk to the owner and not just some counter-monkey that doesn't care.mx-tech gets they're springs locally made to their specs per jeremy.as to oil i recommend 7wt as that is what yamaha fork fluid rates.yamhas fluid is pricey though at $22 a liter.i like belray fork fluid not fork oil.less fade i think.the manual will give you a min-max to work with for level.try somewhere in the middle.it will probably be close although big hits it may bottom.adding is easier than removing as you don't have to remove the forks.just use a syringe from the feed store.play with your clickers from baseline settings and you'll probably be pretty happy.the wr comes undersprung for any one over 165 lbs which seems strange for a bike this heavy aznd powerful.good luck

  • minion

Posted September 28, 2006 - 10:35 PM

#6

For budget reasons, I'd like to just replace the springs for now, and put off any re-valving, etc. until next year (over the winter). My main concern with the suspension is bottoming resistance supporting my heft on jump landings. I prefer trails / woods riding, but will probably do just as much (more unfortunately) on motocross tracks because that's what all my riding buddies are into.


I will throw a monkey wrench into the mix here... I am slightly heavier than what the bike is setup for stock (I'm 190 lbs, the bike is setup for 170 lbs). When doing the spring calculator on RaceTech's site, the front suspension was right inbetween the stock weight, and the next higher up weight. I decided NOT to replace the front springs and to only revalve the front.

I did however replace the rear spring, and there I did NOT revalve. RaceTech's recommendation for the spring was a 5.5kg spring, and the stock was a 5.3kg... Since I don't own any nitrogen equipment, revalving the rear was not an option for me, and replacing the spring was far easier.

Either way, after revalving the front my bottoming problems are gone. I am very tight on my clickers, so the next time I have to replace a fork seal, I'll probably replace the springs as well... But I was able to clear up all of my riding issues with only revalving the front.

I had to adjust my rear clickers, as the new rear spring wanted to buck me off of the bike, being a lot stiffer than the original. :thumbsup:

With your weight, you'll probably want to do both a revalve and a spring replacement, especially if you ride motocross. I'm at the motocross track every week (weather permitting) on my WR450. I never thought I'd be into motocross as much as I am when I bought the WR. I'm glad I was able to make it moto-worthy.

Don't discount revalving. I saw a lot of people on here speak about themselves not being good enough of a rider to notice a revalve.... I don't believe it. Revalving makes a tremendous difference - the stock valving on the WR is WAAAYYY to soft for motocross, and springs alone will not fix it.

M.

  • 2tall2tall

Posted September 29, 2006 - 07:26 AM

#7

I am 6'5" and 235 with a WR400 and a WR426, both with full racetech front and rear. It is a DRASTIC improvement for the riding that I do, trails, singletrack, occassional MX. I have the 5.8 rear and it is perfect. I found the website to be spot on for everything. Highly recommended! :thumbsup:




 
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