KDXRIDER.NET

Well I got to ride my newly acquired KDX250 today for about an hour out on some trails near my house, all I can say is this thing is scary fast! But I am comparing it to my old 72 F8 250 which made a whopping 23 HP when new, needless to say It's going to take some time to get back in the groove, my question is the bike seems really squirrely at any speed, I thought I may have had too much air in the tires but I'm running 12psi in the back and 14psi in the front, I think that is good, so my next guess is the tires??? the rear seems like I'm riding on ice all the time even when there is hardly any power it just slips and slides, the front seems a little better but did almost wash out a few times, the tires that are on are F- Pirelli MT44 R- Dunlop K695. I ride in the woods and it is usually always wet and muddy but some places it is rocky too, I'm thinking the tires I have are the wrong ones for where I ride but maybe it is the suspension, I did measure the sag in the back and it is around 4 inches, I think that is close to where it should be. I want to be able to rip through the woods but every time I give the thing gas it feels like I'm on slicks in the rain!! any suggestions??

Set the sag on the rear...

I think there is a write up in the Suspension section on this...

http://kdxrider.net/forums/viewtopic.php?t=1110

here are some pics of the tires should they be replaced?

the tires are not too bad. The thing is replace them when you feel like your braking is suffering or you have a loss of traction. Im sure you could go a lttile more on them, but i mean if you replace them now you wont have to worry about it. They could be worse but until you really feel loss of control and traction you dont need to replace them

I've seen worse but I would replace them for sure...

For wet winter riding? They are shot

Where we ride, the mud is like slime. It's a red clay, and sometimes the consistency of melted creamy peanut butter

IRC M5B works better than anything else we've tried



Up front the Dunlop 756 works well, but the knobs tend to get rounded kinda fast. I'm running a 952 at the moment. I was not impressed at all with this tire until I tried andjusting the clickers some on my forks. What a difference that made

14 psi is a little high, I run 12 psi front and rear

ive had real good results with kenda millville tires. I think thats what they are called. Very deep tread and not too expensive

Mr Wibbens is that a 110 or a 100?

It's a 120/80 18

thanks I was looking at these in the TG4:
http://www.motosport.com/dirtbike/produ ... DX250;1992

they look decent and the price is right!

Most of the time with tires, you get what you pay for

Never heard of Artrax?


***edit***

Not many reviews to be found on artrax, and nothing positive

I tried a Kenda Trackmaster for awhile and thought it was the ****!

Cost only $40 at that time and lasted a long time

But when I ran it in really challenging conditions, like wet loose loamy dirt, it failed terribly

Took 3 of us to push my bike up a short 50' section of hill

Re: Dunlop K695

Isn't that the tire type KDXs come with? It's not any good when it's brand new!

You will find that everyone has their favorite tire..and thinks it should be your favorite, too. I know of NO one that runs a K695..EVER.

Inda's right. Wibby's right. I'd call your tire good for Prospect (local summer riding area). Nothing technical nowhere..miles and miles of road, no traction required, a days ride will push 150 miles.

Kenda Millville Ha!! Sorry...but 'deep tread' and 'not expensive' count for absolutely squat. I'm glad you like 'em, and you are more than welcome to 'em.

Wibby's right about front air, too. 14psi is on the high side...and a pound makes a big difference.

I recall reading input from other 2-fiddy guys that the forks in OEM form are pretty bad.

Re: 4" shock sag

And what does that make the free sag?

At the very least, change the fluids in the forks. Are these a cartridge style fork? They have a base valve I s'pose. It would take you five minutes to see how that valve is setup. If it's close to OEM average, it's probably got 6-12 24s on the top of the stack..and that's just plain stupid for any trail riding. I recall reading, too, that the 250s (at least some of them) were sprung too soft and valved too hard.

You're familiar with valving?

Front 'washed out' when? In turns? That can come from a lot of things..rebound insufficiences being one, too much OR too little. Change the clickers on both ends of your bike (and both ends of your forks) to see if things you want to improve do...or get worse.

BTW...you understand what the difference is 'tween a soft/hard terrain tire is compound-wise? The tire is opposite: A soft-terrain tire is going to have a more-firm (harder/stiffer) tread, a hard-terrain tire is going to have a less-firm (softer/more supple) tread. That might help you choose your next tire...which should be an M5B.

I run mine backwards.....seems to me it should pack less that direction.

I run Maxxis Intermediate Terrain tires on my kdx 250, front and rear. I beleive the rear is a 110/100/18. They hook up well here in KY, in a lot of different conditions. They seem to be wearing well too, but then again, i dont get to ride a whole lot. On a side note, my 250 has always felt a bit top heavy to me......just something you kinda get use to. But, the ass end shouldnt be getting that squirlly on you. I run 12psi in the front and 10 in the rear most of the time, depending on the conditions.

I'm sure you'll get a lot of different recomendations for tires. This is surely due to different types of terrain and personal preference.

Out here conditions are pretty challenging (gnarly). Here's an example:



Most guys in my area swear by the Pirelli MT 16 front and rear, or if you have a bike without a zappy powerband, rear trials tires have proven to work pretty well also. The MT16 isn't known to be outstanding in any one type of terrain, but works well in most conditions.

We also run much, much lower tire pressure. 6 to 8 in front, 4 to 6 in the rear. Many guys use 2 rim locks in the rear to get away with the low air pressure. The sloppier the conditions, the lower the air pressure.

Well I dropped the rear to 10psi and the front to 12psi and went up to PA where it is real rocky today and I was running mostly in 3rd and lugging it a bit to stay out of the powerband and all I can say is WOW!, I can't wait to ride this thing after some new tread, it climbed everything I pointed it at, and did so with ease, very happy with the bike so far did a lot of stand up riding to prepare for my desert trip next week and I think I need a little taller bar, that and a new rear spring to hold my big ass up!, front end seems good but the back bottoms out a lot.

RE:They have a base valve I s'pose. It would take you five minutes to see how that valve is setup. If it's close to OEM average, it's probably got 6-12 24s on the top of the stack..and that's just plain stupid for any trail riding. I recall reading, too, that the 250s (at least some of them) were sprung too soft and valved too hard.

I'm Cornfused!!

RE:You're familiar with valving?

Not yet! but I'm sure I will be!

I think there are only adjustments on the bottom of the forks, I waiting for my Kaw KDX 250 manual supplement, should shed some light on these things!

What rear spring should I look for is there some magic table to figure out spring rates??

Also where is the cheapest place to find an M5B? $58 was the cheapest I found thus far, and do the do well in rocky conditions as well?

here is a pic from today's ride:

I see your problem... you had a big green sucker bug on your butt!

Re: '...pic from todays ride...

Did you ever get to any trails...or just stayed on roads?

$58 is a decent price.

Re: 'magic table to figure out spring rates?'

No magic table. With a race sag set to 100mm (4"), your free sag should be about 3/4" to 1 1/4".

If you have NO free sag, your spring is too 'small'...too low a rate.

If you have considerably more free sag than 1 1/4" (say, 2" just for a point to figger from), your spring is too 'big'...too high a rate.

That's how you figure it. Set your race sag for what you want it to be (some prefer less than 100mm, some more..but probably not more than 10mm difference either way), measure your free sag (amount the bike drops on its own weight, standing straight up..no rider), choose a spring to make the numbers within reason.

I didn't read all the way through, but this:

http://www.mb1suspension.com/id8.html

has some good information in it.