KDXRIDER.NET

Pulled the KDX out of the shed yesterday and woke it up from its winter sleep. I had gathered up a set of 01 CR 125 KYB forks/axle and a KX 250 triple tree, lower tube guards, and a CR master cylinder/line/caliper and a 03 CR 250 wheel assembly over the last couple of months.

Broke down the forks, cleaned them, installed new oil at 145mm air gap (CR specs ~ 100-110mm). Forks do not appear to have ever been worked on but the oil was apparently changed because it was in VG shape - No pre-load spacers but about 10mm of pre-load on spring when asembled - one fork leg was seriously overfilled (oil poured out when I dropped the outer tube)

Upper triple tree was 2mm too large for the forks so had a set of alumium split sleeves made up to take up the slack. Also had a 1/4 spacer and sleeve made up to fill the space between the KDX stem and the KX upper tree stem hole. Lower triple tree was correct size for the forks.

NOTES - Neither stem had any loctite on them when they were pressed out. I used Loctite 'sleeve retainer' on all sleeves when I installed them after cleaning both mating surfaces with acetone. ( No I did not loctite them to the fork legs or the steel stem for those who may question thisl)

KDX caliper bolted right on to CR fork so I'm going to run that and the line length is longer better fitting the KDX (This was a pleasant surprise) Honda plastic fork guard has a molded mounting spot for the brake line so I pulled the hose clamp from the KDX forks and bolted it on - no zip-ties needed. Remounted the KDX light assembly.

I could not finish the job since I need to round up a front wheel axle spacer which I quess will likely need to be ordered so a ride impression report is likely a week away.

I measured the KDX with the stock forks in place - measured from the back side and bottom of the headtube to the ground - 34 1/4 inchs and now I sitting about 3/4 inch higher with my fork legs approximately 3/4 inch over the top of the upper clamp. I am going to raise the handlebars so I can raise the forks in the triple tree a little more. (Still have about 3/8 inch of lower fork leg clamping surface area.)

Anyway - that the basics of the conversion.

Great info Charley, especially about the brake line routing.

Sounds like your on the way IC. That setup is going to make all the difference in the handling department for your son's KDX.

RE: '..so had a set of alumium split sleeves made up..'

That's a quick call to a local machine shop?

I think this has been brought up before...but with all this mixing and matching of parts, who's going to have the first KDX with Showa legs?


Why 145mm?

What the spring rate?

That Honda fork guard I suppose is white in color?

No.

CC wrote - " RE: '..so had a set of alumium split sleeves made up..'

That's a quick call to a local machine shop? "

Yep - about 2 1/2 hours later had a set of split sleeves in hand, a collar with spacer for the stem differences and the KDX stem installed in the KX triple tree. $82 for the work and materials. I though this was a very good deal and really did not expect the work performed this fast!!


CC wrote "Why 145mm?" Just by filling the forks with oil and pumping the rebound rod this was the lowest level that I was comfortable with without introducing air into the circuit. Figured I would start low on oil (since it is easy to add) and allow the air spring to be soft to get a better feel for the mid and base valving set-up.

I picked up the spacer collar for the axle Wednesday afternoon and have revalved the forks twice, have added 10 cc of oil to each leg and have lower the forks in the clamps about 5mm from the initial starting point. These fricking CR 125 forks were very very stiff initially. I don't have the shims I want for the next revalve attempt so I'll need to order some Tuesday from MX-Tech before the next revalve. They are ridable now I believe but still not as good as I would like for Sam.

CC Wrote - "What the spring rate?" It appeared the forks had never been apart and the fork legs did have stock valving in place. So I'am assuming the stock fork spring rate of .43 is what we have. I feels like it to me also from the limited riding I done adjacent to the house (I typically run .44s in my KTM since I've become rounder )

I went ahead and set-up the preload on the KDX shock for my weight while I check out the front leg changes and it does feel pretty balance to me after I dropped the fork legs in the triple tree - this set-up is going to vary quite significantly from what many of you running: Not saying it is any better - but just different.

The front forks have about 60-65 mm of race sag with me on the bike with the current set-up and feel pretty good on a little track in the neighbors field. Haven't ridden it on the trails yet and likely will not until next week. Boy number 4 has a Soccer State Cup tourament this whole weekend.

CC wrote "That Honda fork guard I suppose is white in color?" No way - white just would not be acceptable and I would have had to buy KX forks!! Black is the color of the fork guard.

In keeping with 'What the spring rate?', may I further say/ask...

Thank for info!

Good deal for 82$.

You be now bout won inch up in clamp? Is back stocked pull rodded?

Black is good. U never haf to go back words so I heard.

IC are you going to keep running the presumed stock .43's? Or drop to something a little lighter for your son?

CC - Actually I only have about 1/2 inch of each fork tube above the upper triple. That is what really surprized me the most - Please note I have not yet ridden this bike with the new forks in the woods. Do not really know how it will feel in down hill or uphill turns etc. The bike is sitting higher in the front I'am sure but felt good in the farmers field course.

m0rie - Going to stick with the 43s until the valving is dialed in then may change it for the boy who is about 165 geared up. Don't know for sure though because if he doesn't ride it more than last summer it may be a second bike for me until the next son's legs get longer. I'm sort of hesitating a little since I think Sam will likely put on 10-12 lbs over the next year and he did not ride it much last year. Tennis and girls and hormones are confusing the lad.