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08 YZ450F Springs

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I have played with the Race Tech spring rate calculator a lot. Based off 155-160 Beginner to Novice and with or without a desert tank, it recommends Fork springs as low as a .404 kg  and as high as .42 kg. Shock is pretty consistent at 5.1 and 5.2. 

The question I have is where to get correct springs.

 Race Tech offers front spring rates of .40 kg or .42. The shock 5.0 or 5.2

Factory Connection front rates are .41 kg or .43 kg. The shock 5.0 or 5.2

Do I go with softer .41's from FC or .42's from RT?

.41's I can gain 10 pounds or get a desert tank and still be good. 

.42's maybe a little stiffer but I can grow into if I get more skill? They will be good for me to add 10 lbs and get a desert tank if I ever needed. 

 

I don't race. I don't ride track much at all. I ride woods, trail, single track, desert, hill climbs, small jumps ect. Nothing real slow nothing real fast. I'm 5'7 155lbs. 37 years old. I consider myself Beginner or Novice since I ride for fun and do not compete, other than an occasional Virginia City Moto X or hare scramble or so.

 

I was thinking of getting shock rebuilt only if I have it lowered an inch or 2. I can barely tip toe and I already shaved the seat foam. (As I start to tip over or fall, the bike normally has too much momentum for me to keep it from falling over.) I set my forks up in the triple clamp 7.20 mm

 

I have never sprung a bike before. I was going to service the forks myself and maybe send the shock out. Bike is older but with very low hours. I want to change the oil and seal, and a buddy of mine said do the springs while I'm there.

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0.42 is as soft as I would go on a 450 and 5.2 rear sounds about right

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Scary, I am almost exactly your size and age, would consider myself a novice to intermediate rider on terrain you described and just sold an 09 I rode for 5 years.

Shock spring and fork springs are easy to do yourself while doing the front seals.

I had .45 and 5.2 springs but did not mess with the valving. The softer spring rates from stock definitely helped a lot and I thought it was great.. until I road a purpose built Enduro bike that was designed for woods, trails, hills, and single track. I ended up ditching the converted mx bike.

 

I'd suggest the .42 and softer 5.0. Little softer in the back might help your short legs reach the dirt. I wouldn't bother with lowering bike and robbing from the suspension travel. You will appreciate the travel as you get faster and more use to the bike height.

 

 

 

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Hoosier-Daddy   Thanks for your input. If money wasn't an issue, I'd probably have a newer Beta, KTM, or Husky. :) I got this 08 used and it is my first 450 /  real bike. I do prefer lighter weight since I can't touch that well. E-start, battery, lights, ect, start adding weight that I have to try and control.

My rides are never rock crawling slow like some videos but I'm not hauling ass all the time either. When I say trail or woods, a lot of people think I'm putting around in low gear at walking speed.

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I get it. Sounds like similar riding I do here. Flowing through the woods looking to hit some single track if I can find any. Don't let the weight of the purpose built bikes scare you off. They actually feel lighter and less exhausting by the end of the day than my 450 did.
Side note- you should try a heavier flywheel if you haven't already. Heaviest gytr works wonders. Use the puller if you get one.

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FC said .42 was too soft so RT spring cal might me too soft for me. Maybe I should find some cheap .45's and a 5.3 to try. My manual shows part for 5.5 STD, 5.3, 5.1, 4.9. in Titanium. So if I stay stock I'd be 5.3 or 5.1. 

 

I know a guy with a 4.9 but would it be too soft?

Is the titanium worth it? I want to keep the weight down as much as possible.

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Mog, any thoughts on the titanium vs steel spring?

So at 155 pounds puts me at 70.3 KG. According to the chart 4.2 would be light but is that for MX?  Factory connection has a 4.3 spring.

I kind of need to get this right one time because of finances.

E-bay has a titanium spring from an 06 YZ. Guy said it was a 5.13 kg. If that spring will work for me, It may save me a few $.

Edited by supermo26

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The ti are slightly progressive, not a good or bad thing , just how they are , this chart is for mx only , so you will need to go lighter for woods , the chart is nm to convert to kgmm add 0.1

 

So the ti 5.1 should be good and I would say 0.42 0.43 for forks

 

 

 

 

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