KDXRIDER.NET

I have searched on this topic and have not found exactly what I was looking for.... yet.

I have an '02 KDX and a '95 KX. I ride them both and sure do wish the KDX motor was in the KX. The KX geometry and weight are great, the motor is a handfull.

What holds me back from doing a hybrid is the swingarm issues. It looks like the KDX swingarm will bolt right up to the KX frame, if the KDX engine was in there.

Why have all of the hybrid builders I have seen opted to either mill the KDX engine case or cut the KX swingarm?

Am I missing something magical about the KX swingarm/rear suspension?

The KX swingarm is about an inch longer than the KDX swingarm. Apart from that it looks like everything alse would move over. I would have to use the KX shock and knuckle but probably a custom pull rod length.

Thanks in advance for any insight

A KX is a better and stronger frame including the swing arm. Putting anything from a KDX on to a KX would be going backwards. I only know one person that put the KX swing arm on a KDX. The cost and trouble and the irreversibility for so little gain if any, were more than enough to keep me from doing it.

Except the motor for the intended purpose Brad!

Brad-

"I only know one person that put the KX swing arm on a KDX."

Did you mean KDX swingarm on KX frame? If the swingarm and engines stay together, not cutting appears to be required

OOOOOHHH! I see what I totally misread the first time. As Roseann Rosanna Danna would say "Never mind"

A KX what?

Put in an autoclutch.

Ski rode a KX250. When he properly tuned the suspension and put in one of Gary's clutches, it was a very good woods bike. I've ridden with him on some pretty nasty stuff (mountains made of shale). The KX (well, and the rider of course) were impressive.

Changing all this 'stuff' between one and the other makes no sense at all.

I've seen KX500 riders (CR500s too) that do just fine (better'n most) in the woods.

Tune your bike!

Amen to that (KX500 thing) . People get swept up in this woods vs. MX bike thing way too much. I used to think the same way till I started riding an MX bike in the woods occasionally. What I found is the MX bike has no trouble flat out ripping in terrain I ride in. The motor is a lot different, but being a human and all, I adapt to the motor instead of making the motor adapt to the terrain. The suspension is stiffer, but If I pick up the pace a bit, it feels a good bit more secure and precise than my KDX. For slower paced, or just plunking around type riding, the KDX is tough to beat. But if I had to replace it today, I'd be on a YZ250 or KX500 with a big tank in a heartbeat.

How lunch to the friction discs last in an auto-clutch that's slipping half the time? Just curious...

They don't last long if they're slipping half the time.

But...if they're slipping half the time, you should'a already fixed it!

The engagement point is quite adjustable. No reason for too much slippage.

Yeah, I guess that was a bit of an exageration. I guess my point is when you are in that range where the auto-clutch is making the close ratio trans user friendly (or riding a gear too high) there has to be some above average slippage going on. Granted it's a huge wet clutch designed for abuse, and some manual clutch-ers beat the crap out of them pretty good....Probably much harder than I was describing. I was just thinking along the lines of average woods rider = 2+ seasons on a clutch. Average MX rider = Less than one season on a clutch. Just curious as to where the auto-clutched MX bike would fall. My guess is not too many(if any) people on here have used one enough to even know. I know Ski would by now, but his poor auto-clutched mill was turned into a chunk of ore.

Ski's 250 slipped a whole lot less than his 220. Seemed the 250 had the power to lockup the clutch and go while the 220 did a little RRrrrrRRRrrrRRRrrRRRrr-ing trying to get moving.

I rode his 220...he never let me close to the 250. Sure, he said, 'You gotta try it!' but anytime I got close to it he gave me a dirty look.

YES he did!!

I appreciate all the replies, and agree with most. I'm not real fond of the autoclutched bikes I've ridden, but I suspect that is an age thing.

The thing is I like my KDX motor, and I like my KX frame. I'd like to build a hybrid, kind of just for fun.

The question involved the swing arm/motor compatibility, and why the KDX case is cut or the KX swingarm is cut.

I've got a Buddy that supposedly has a completed hybrid, currently partially apart for painting that the recently divorced owner had to dispose of before the courts did.....I'll go look at it.

My longer term plan is to buy a GasGas. I've had the opportunity to ride several and, IMHO, are far better than an MX bike, whup a KTM, and make my KDX feel like an old CT-70. Of course, for $7K.......

I'm not an autoclutch fan, either. That's why my bike doesn't have one!

Still, watching that KX crawl up that rock mountainside was impressive.

Having a rear brake at-hand (if you put that option on) can be very handy, too. Turning Ski's bike around on a narrow side-hill trail was a snap!! NO way I could have done that in the saddle..with the front end up the hill and the back end on the trail, my feet would've been four feet off the ground. If I had no access to the back brake there is NO way I could have held the bike on the trail when its nose was up in the air. With the autoclutch it took a grand total of three seconds to flip the bike around.

I'm not good enough with a clutch to stand the bike on its back tire and turn it around on a dime. I've done that on uphill switchbacks..but there is some forward movement allowed in that case.

I just can't quite let go of the clutch idea, though.

Anywho...I'm sure such a swap is doable. I've seen blown V-8s in wheelbarrows, so what's a little engine swapping between motorsickles?