Dirt Bike Modifications Forum

What's all this talk about those other silly links?  Here's the answer to all of life's questions.

http://www.dirtrider.com/tech/141_0411_set_up_your_dirtbike/index.html

hey, its not silly. although that link you pasted is pretty darn good. yes that should help him figure it out. thanks pete

hey the average guys at mxa weigh about the same weight so it will work for you and then you just need to fine tune the clicker adjustments.. so good luck and yes dlhamblin if you look at the first post he says its a crf450 '07. ok bye

I went to my local dealer and talked with a mechanic that does my engine and suspension work. I gave him my race sag and free sag, the technical term, not static sag. He said that I would need to go softer spring for my riding style. He recommended that we do the forks and the shock springs at the same time to keep the suspension balanced. To determine how soft to go he showed me a site that is called http://www.racetech.com/ (someone posted it before me). We typed in my weight and the terrian, like motorcross or desert. It said that I need to  drop to a 5.10 kg/mm from a 5.5 kg/mm and the front fork to a .446 kg/mm from a .460 kg/mm. For fun I typed in the weight of the rider on the race tech site tell I found the right weight for the stock spring. The forks were rated 183 for motocross, the shock was rated 210 for motocross to. Thats why I have to go to a softer spring, I only weigh 150 pounds.

Yes I ride a 2007 Crf450, sold the RM250. Thanks for all the help, your dumb before you are wise! I am starting to understand.

Because I couldn't find the link YOU posted :-)

Hey all got my forks and shocks back from the shop. Had them put on softer springs and new oil. Never thought that it would make that big of a difference, but it did. It chewed throw the whoops and felt plush on the big jumps at the dunes. I had them put amsoil shock oil in the forks and shock, I never felt the suspension fad out like it normaly does with stock shock oil. The suspension mod made the 07 CRF450 more enjoyable. I went with Factory Connection spring for those that want to know. Thanks for the help  

good for you,your welcome. i was gonna get a revalve but i cant afford it now cuz im getting regualr valves for the engine.it sucks but i keep saving for it. i dont know why but i struggle with my suspension. i would really like to get some. but not before i get engine gaurds, radiator gaurds,and some other small little things like that

I have one last quetion about the front forks. Is there a spec for race sag and free sag for the front forks, or does that mater or apply for the front fork?  

no there isnt, they just have to work

Thats not necessarly true. If you have made the correct fork spring choice and the correct shock spring choice for your weight and riding style and riding application, then the front sag should be about right when you set the rear. if your springs are to stiff you will ride high in the stroke, soft and you will ride low. Both causing different types of handling problems.

Do you want your bike to set level? A freind that I ride with said that you want to use all the suspension, top all the way to the bottom. When you watch the pro racers in the super cross races, when they are going throw the whoops or anything their front and rear suspension is almost always very close to the bikes fenders. Is that what you want to have? I never hit the bottom of my fenders. My freind is a older husky kind of guy and when I sat on his bike it felt to soft, but it chowed throw the bumps. I hit a lot of jumps to me his supension would bottom out to much. I have my suspension set up a little stiff for jumping. It chows up the whoops. When my freind was watching me ride he said that my forks looked stiff. When you look at my bike from the side the front of the bike is set high. Could that cause stiff suspension or is that more for handling?

well yes if you watch the pros they use up a lot of the travel a lot of the time. i had my suspension set up stiff with the forks a little stiffer then the shock partially cuz im short and want it to ride lower in the rear and and also cuz if i drop the front end in the whoops i dont want it to bottom and throw me over the bars. but at the lsat practice of the year i messed with my suspension and stiffened them up and they worked really good through the whoops but then they sucked on braking bumps and off of jumps. so i had to soften it down. some people like soft, some hard.

It depends on what you're doing. But your suspention sould work for you and feel good to you, but it needs to be balanced or your bike just wont handle.

Gary Semics explanes it fairly well in his video on bike set up. But if you want a more in depth explanation and on what the fork and shock action sould be, you should check out http://www.finelinesuspension.com/. They have a video called "Basic Suspension Tuning" and it explanes a lot for both moto and off-road. The Fine Line viedo explanes a little better about the effects of compression and rebound and how to make them work for you.

Also, any good suspention site should be able to explane what you are asking about. Good luck.

I lowered the forks in the clamps a little bit trying to level the bike out. That helped a lot in the handleing department. Chews up the whoops and all the little bumps and ruts.

I have been e-mailing RG3 some of these some questions and he sid that a revalve would have solved the problem. I am not sure, Have any of you guys gone the revalve way instead of new springs. How did you like the revalve? Was it worth it?

I had PRS re-valve my 450X, There was a lot of difference in action, but I kept the same springs as they were correct for my weight and ability. Will a re-valve work for you? If you are having problems with your suspension and its action, then I would drop the coin and have your boingers redone by a reputable company that will warranty their work.