04 450 Suspension


5 replies to this topic
  • SoCalEngineer

Posted July 29, 2004 - 05:30 PM

#1

I tried the Racetech calculator and based on what I have read here I don't know if I should trust it. I entered the 210 lbs and selected Supercross due to the size of some of the jumps at Lake Elsinore. The following information was provided.

Type of Riding: Supercross
Rider Weight: 210 lbs.
Recommended Spring Rate: 5.60 kg/mm
Stock Shock Spring Rate (measured): 5.3 kg/mm(stock)

I determined my rider sag, following guidance on the TooTech site, by setting it on the stand to get the reference and then standing on the pegs to measure sag. With it set at 100mm I was left with only about 1/4" of free sag. Per the info on the TooTech site I need a stiffer spring to get more free sag. Posts indicated a 5.8 would work well for my weight.

I am not sure what way to go here. Do I trust the racetech calculator and get a 5.6 or just go with a 5.8? Is there a good reference?

Thanks

  • Hank

Posted July 30, 2004 - 04:26 AM

#2

Start by deciding what your ideal weight is... I almost need a stiffer spring because of the same free sag issue... I have been getting back into shape though so I can take the big crashes again.. So I plan on dropping my weight a bit maybe 10 lbs and that will bring it right in to specs... That racetech calc is pretty handy... I would go by that if your buying one of their springs... Who knows them better than racetech... :thumbsup:

  • SoCalEngineer

Posted July 30, 2004 - 09:46 AM

#3

Thanks Hank. I don't have much spare weight, but losing weight is definitely the cheapest way to shave weight off your bike :-) and save for some more beneficial upgrade s than springs for our overweight behinds. :thumbsup:

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  • Lackey-92

Posted August 02, 2004 - 03:23 AM

#4

Hi,

I am 210 lbs and ride an 04 YZ450F. When I revalved my suspension I went with a 6.0kg rear spring and .48kg front springs. I'm a fairly fast rider in Texas. I usually ride at Cycle Ranch (VP) in San Antonio and it will use up your suspension. I tried a 5.8 but it was still a little too soft. On my '03 and '02 4xx I ran a 5.8kg but the '04 needed a 6.0kg.

  • Vet28

Posted August 02, 2004 - 06:31 AM

#5

***DO NOT TRUST THE CALCULATOR*** THE 450 IS SPRUNG FOR A 185 POUND RIDER. OBVIOUSLY, IT CAN BE SET FOR HEAVIER RIDERS (LIKE MOST OF US). I AM 190-195 AND STILL USE THE STOCK SPRING. FOR MORE ADVANCED RIDERS, THE STIFFER SPRING IS REQUIRED. FOR YOUR WEIGHT, I'D CERTAINLY OPT FOR THE STIFFER SPRING, NOT TO SAY YOU ARE OVER WEIGHT, BUT YOU ARE 25 POUNDS HEAVIER THAN THE BIKE IS SET FOR. I FOUND THE RACE TECH CALCULATOR TO BE SEVERLY OUT OF WHACK FOR ME. YOU'D ALSO DO WELL TO GET STIFFER FORK SPRINGS. I RUN THE 49 SPRINGS AND FOUND THINGS ALOT BETTER.

ENJOY,
VET28 :thumbsup:

  • grayracer513

Posted August 02, 2004 - 07:00 PM

#6

I sometimes weigh 185. Mostly I weigh closer to 195. When Precision Concepts did the suspension on my 450, they used a 5.8 in the rear, and according to the static vs. race sag comparison, it's the perfect rate. The forks got .48s, and feel considerably plusher with the stiffer springs, since I need less compression damping now, and the bike doesn't dive so hard when I brake hard.

I think the stocker is sprung for something more like a 165 pound rider.





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