Need some help..

[Ryan17]

I have an 02 kdx 200. I weigh right at 250 and i am starting to do some biger jumps and i am bottoming out the rear suspension. What are some things i can do to sovle this. Is there companys that make good after market suspension stuff for these bikes? I will be buying a MX bike next year but would like a temp. fix for these. Thanks for any help.

 

[gwhII]

Have you already switched your shock spring? If you go to racetech.com, they have a spring rate calculator which will take into account riding type, weight, and skill level and make a recommendation. I weigh 230# and got a different spring and like it. Cost was around $109 for the spring. They can also provide fork springs and custom valving for your forks too. Summers racing has a fork brace kit but expect to pay about $250 for the kit and you would have to modify your front fender. The brace will stiffen your front end.

Best,
Greg

 

[canyncarvr]

1. The kdx is not an mx'er
2. 250# is too much for the 5.0kg/mm (oem) shock spring.
3. That weight is also way!! too much for the front-end, and a balanced bike is important.

There are many companies that 'make good after market suspension stuff for these bikes.' They are the same companies that make the same good stuff for everything that's not green, too. MX-tech (jeremy wilkey) for one.....FRP (fredette racing products..jeff fredette) for another.

A revalve/respring for both ends will run you only around $1500. ;)

Save your money for next years mx'er??

 

[Ryan17]

I know the KDX is not a MX'er. This was my first bike ever. Ill cheek out that website. Thats what i might do for a temp. fix. Thanks

 

[canyncarvr]

There are all sorts of steps between oem and 'fixed.' But one thing usually leads to another, pretty soon you've spent some real bucks on a bike that won't do what you want anyway, so why bother?

IF all you want is more spring in the back...run your stats thru a racetech.com spring rate search and get a number (probably something like a 5.4kg/mm), then buy a spring that fits from whomever you wish. It only takes a few minutes to change the shock spring.

Be sure you set the race sag. I'd say do that now...but at 250#, you're not going to end up with a reasonable set-up. If you could even get TO a 100mm sag measurement, your free sag wouldn't even exist.

Even with a new shock spring....a 5.4 rear and the .35 fronts are going to be a mess. As long as your re-springing things, doing both ends would be a big advantage.

Do the work yourself, and the springs alone (front and rear) will run you less than a couple hundred bucks.

Good Luck!!

 

[gwhII]

For my weight, which isn't terribly different than yours, I definitely noticed a difference with the right springs, especially with the front end diving. Your needs are different than mine but you should find the right springs more confidence-inspiring. I only mentioned racetech because I only have experience with them and I've been happy with the results. I also found the Sagmaster tool useful since it made measurements easily repeatable. It really is only a small metric tape measure with a stud added which fits into the axle. Others offer a similar tool. Like CC said, good luck!

Best,
Greg

 

[Ryan17]

Thanks for the advice. Ill order the stuff this weekend. Is there any other special tools that you need or make the job easier.


Thanks agian.
Ryan

 

[canyncarvr]

What stuff? Front? Back? Both?

A spring holder for the forks is handy. You can make something or use a wrench. A search of this site should help you. Have some pvc pipe on hand to make a realistic preload spacer. The oem setup is stupid (about 40mm). With new fork springs you will be changing that. With a coldwound spring (what you'll likely end up with) a preload of 10mm or so is fine if your spring is the correct rate for your weight.

Might as well change the fork oil. Get yourself a syringe from your local grange/vet shop...and some tubing that will friction-fit on the end of it. The basic idea is to overfill the fork (spring out, fork collapsed..no bubbles in the fluid), then use your syringe with the tubing cut to the desired length to suck out the excess fluid. 110mm or so is a good starting point for oil level.

Take a look HERE at matt's tutorial that will give you some good pointers.

For the shock...you can loosen the locking ring with a drift or punch if you don't have the right spanner. Loosening (and tightening) the lock-ring will probably be easier with the shock still on the bike. Loosen (or tighten on reassy) the spring by turning the spring by hand. A bit of soapy water on the bottom will help it slip.

BEFORE you take the spring off the shock, measure (or count the threads) your current setup position. That will give you a general idea of how far to squeeze the new spring before you put the shock back on the bike. Easier to do on the bench than in the bike.

Depending on how much trouble you want to go to...slipping the carb out of its boots takes about 30 seconds....and it being out of the way will give you a whole lot better access to adjust the shock when it's back on.

Which..btw..you understand race sag/free sag...what they mean, how they're set?

Don't bother wrenching on anything until you understand that process. You must set your sag when you replace the shock spring.

Otherwise, if you're generally mechanically inclined, it's not a great big deal.

Oh...be careful on reassy of the pull rods (dog bones)...yanno..the unitrack knuckle stuff? It's real easy to tighten the pull rod against the shoulder of the bolt. That's not right. The bolt shoulder must extend through the pull rod. You can use a c-clamp to hold it together whilst you attach the fasteners.

You're going to clean/grease the suspension linkage while you have it apart...right? If you haven't been doing this on a regular basis (three times a year or so), you will likely find the bottom shock bearing is toast. Put it back together with a new bearing/sleeve and seals.

All sounds like a lot of fun, huh? Whew!! I'm ready for a beer!! ;)