heavy fork springs

I just had a guy put in .5o fork springs for me and 3 wt 390 cc oil to compesate for mt weight. Now it seem that the forks actually sag more under its own weight. i wouldve thought that the bike would actually have less sag because of the stiffer sping. I am sure the bike sags more because i now need to lift the front to put the fork support between the wheel and the fender.

Sounds like you have less preload,(shorter springs)

When I installed heavier fork springs in my XR650R I found that Race Tech springs are not the same length as the stock springs. The instructions specified the amount of preload, but Race Tech does not supply a spacer (I consider this a shortcoming). I had to fashion a 15mm high preload spacer out of thick walled PVC tubing. Now Eibach springs are the same length as the stock springs and the job would have been easier. Race Tech springs are individually tested and guaranteed to be the exact rate that you ordered. I like the Race Tech springs, I would have preferred not having to make my own spacers.

At any rate, you probably need to add some preload. Maybe as little as 5mm which could be accomplished with two heavy steel washers. The diameter is critical.

I never even thoguht about the lenght of the springs. i just assumned they would be the same lenght. damnit!. I am 6'4" and i need every inch of fork hight that i can get. this blowz. oh well. gotta get it shimmed then.

I put .52's in my front and all seems to be the same. If you just bought the springs I'm sure they'd take them back incase they're wrong. I had to send mine back 3 times till I finally got my sag set for my big arse.

mgood-how big are you? I am about to change my springs and don't trust what the parts guy says. what should i use being 250 lbs(ex-bodybuilder so alot of the weight is in my chest, shoulders, and back)and riding (fast) in the Florida sand whoops.

I'm 6'2" at about 280 lbs. Just off the top of my head I'd say a 5.6 or 5.8 in the rear. Best thing to do is go to one of the suspension websites (I prefer MX-tech.com), they all have calculators to estimate your spring ratio. Another thing I learned, even though some disagree with this, is that different manufactures of springs seem to be different when you compare them with the same spring ratios. I always run race tech springs but one time I couldn't find them heavy enough for me when they first came out with the yz400 so I had to go with pro circuits. I ordered a 5.8 for the rear and couldn't even come close to setting the sag. I ended up with a 6.4. And that was when I was at 260. Now on the CRF I run 6.2 but I'm 20 lbs heavy. I'm losing though.

You can't judge from bike to bike, different linkage ratios (as well as other variables) from machine to machine will require different springs for same rider

waynes_world_450 said:I am about to change my springs and don't trust what the parts guy says. what should i use being 250 lbs(ex-bodybuilder so alot of the weight is in my chest, shoulders, and back)and riding (fast) in the Florida sand whoops.

I was at 245lbs and wsa using a 5.9 rear and .50 fronts, and it could have been a bit stiffer. I would think you would be good with a 6.0 and .51 or .52's in front.

I am at 229-230 now and my race sag is spot on with the broken in 5.9. (10lbs more to go to be at my target weight of 220 and 6'4")

Im 6'5 275 lbs and have installed 6.o and .52 springs. They are both from race tech. I have found that the rear is awesome but the front could be a bit stiffer. I do hit some pretty big gaps and seem to bottom the forks out to frequently! If I cant find bigger springs I guess at last resort I'll have to lose some poundage... :)

I am riding an 03 CRF450.


is your valving stock?

what about your oil level?

you could start w/rasing your oil level, unless your are at around 430 to 435cc's already.

if that doensn't work and your valving is stock you can revalve to a spec that resists bottoming better than the stock valving


yes my oil level is back at the standard level as stated in the manual and the valving is stock as well.

do you think oil weight or more oil would help? I heard valving was good and should leave it alone. Is revalving a must with my weight?

thanks for your help.

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