KDXRIDER.NET

Hello. Bill here, from Florida. I purchased a 2005 KDX200 used. In process of refurbishing it for my son to race. Top end off, getting cylinder serviced and new piston. Suspension off front and back, new tires, bearings etc. Took shock and forks to my suspension guy for routine maintenance. He called to say the forks were not stock KDX forks, but probably 98? KDX250 forks.

This will be for my son to race hare scrambles (not MX) in Florida (mostly). He is 17, and a solid C rider. Just finished his first complete racing season on a Honda CRF-230. He is small (about 120 lbs and 5'-6" tall). I wanted to lower the bike a bit so his toes can at least touch ground. Purchased adjustable lowering link from eBay. Seems like good news having KX forks on front. Suspension guy is installing lighter springs (says they are "stock" KX250 now). No changes planned for shock (yet).

Wondering where to start on lowering? How much to lower rear with adjustable link (link length compared to stock)? I assume we will slide forks up a bit in clamps, but how much? Also, I read that KX forks are longer (unless cut). How do I tell if they have been shortened? Where to set fork height (or how to level with rear)? Any other suggestions or considerations?

I have a good suspension guy (several actually). I'm sure they can dial it in for us, but I want to get it close before I take it to them, since this is not a "standard" case (not sure if they've lowered KDX before).

Hi (me again).

Just discussed this with suspension guy again. He sees no evidence of current KX250 forks having been shortened. We agree that we want to shorten them, just don't know how much. He asked if anyone knows the length of the stock ZDX fork (2005), measured from center of axle to top of fork cap (or to top of seam between cap and tube. Obviously, he knows the length of the KX fork.

Hi Bill, Welcome to the forum!
Yup, you'll need to shorten the forks to ensure proper geometry, especially if you lower the rear. I had my forks shortened by about an inch (just under IIRC). Installed flush with the top triple (2003 KX 250 front end) put the bike back to stock geometry. I want to say the stock KDX fork length as measured from the top of the top triple to the center of the axle is 26.5".
Is your suspension guy going to cut the springs or wind new ones?

My suspension guy had me set my 01 KX 250 forks with 12mm sticking above the upper clamp. Bike is perfect as far as I can tell. We did not shorten the forks. I don't have any idea what lowering the bike would do.

Welcome to the forum and good luck on the project. My stock 02 220 forks are 37 7/8" from the axle center line to the top of the fork tube (or bottom of the cap). What part of Florida are you guys in? I'm in Sarasota. I was going to go to Croom last weekend but the pouring rain both days convinced me to hang around the house.

Tropicoz - What does "just under IIRC" mean?
That fork measurement seems a little short. I believe he said he would add a spacer. I think this keeps the tube from fully extending, thus shortening the fork (and lessens travel obviously). He did also mention something about cutting the spring seat though.

John - We are in Gainesville. We do the full FTR circuit and are heavily involved. You should join us if you aren't already in FTR (http://www.FloridaTrailRiders.org). I don't make it to Croom much anymore, but plan to in next few weeks.

If
I
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Damn
Kids

I'm not involved with FTR but read up on it and it seems like a great series with a lot of comradery. Hopefully someday we can meet up.

John_S wrote:I'm not involved with FTR but read up on it and it seems like a great series with a lot of comradery. Hopefully someday we can meet up.

You should come to our Awards Celebration / expo in Daytona at end of July. See www.floridatrailriders.org for info. Tickets are only $10.

Update: Finally got bike together. Took a while due to my broken leg and surgery. Test ride last weekend. Seems awesome (both motor and suspension). Boy is actually 5'-3", not 5'-6".

We ended-up dropping front (KX forks) by 1 inch (10 mm internal), and slid-up 15mm in clamps. Lowered rear 1" with adjustable link. Initial sag was 99mm (38 static) - not bad for initial guess.

Replated cylinder, new piston, new tires.... Happy so far.

OUCH!

I am glad you are better, and it sounds like the bike is too.