other options for kx/kdx hybrid- take a look

Discussion for swapping a KDX motor in a MX frame...
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volkoff
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other options for kx/kdx hybrid- take a look

Post by volkoff »

I am still thinking hard about the hybrid thing. I understand the use of the KDX motor with the lower torque and reliability, I understand the KX suspension (mainly the front) is better. I wonder if it would not be easier to just swap the kx front end(forks,wheels, and brakes) and then modify the KX seat and maybe a larger IMS tank for a KX. (bonus, there are a lot more street legal kdx bike vs. kx bikes maybe they are easier to pass)I think if you are have to grind and drill out swing arms and cut and move motor mounts, grind crap off the motor and push in the tank to make it all work, this has got to be easier. I have no experience at all with either bike, just thinking about how complicated the normal hybrid can be. If you do not have the motor lined up correctly you are just putting a large amount of load on the counter shaft and bearings,chain and sprockets. For me if I am building something it needs to be do correctly. I know the frame geometry is different, but I think if you can get the same seat/tank setup you are going to get a close riding position. And as for the weight they should be close. I hope someone can shed some light on this.
De250r
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Re: other options for kx/kdx hybrid- take a look

Post by De250r »

From what I've read the frame is wider at the pegs on the Kdx . And the weight is lower on the kx frame making the bike feel way liter then it is. You might b able to modify seat /fenders but ull prob have more time modding that to make it look right than u will have in drilling the engine case out and moving a couple motor mounts. I would rather work with steel anyway cause u can weld steel back together/fix your mistakes. Plastics well not so much. It's up to you and your skill set and what u want the final product to b.
here's my latest build. 84 aircooled in a 2005 kx250f chassis. Very easy hybrid reallyImage


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bufftester
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Re: other options for kx/kdx hybrid- take a look

Post by bufftester »

The KDX frame is nearly identical to the KX frame in the lower frame tube/peg area. In fact the motor mounts on a KX almost line up with the KDX motor, and they do vary a bit from frame to frame. On my hybrid I had to cut off the lower engine mounts because they were slightly too tight for the motor to fit, but the upper ones were not. I have seen other KX/KDX builds where they were able to reuse the existing lower engine mounts. As for aligning the drive line, all the components are in nearly identical locations relative to the engine/swingarm (that's the good thing about engineers, we're lazy and like to reuse measurements as much as possible). The only reason the swingarm is cut is to accommodate the slightly wider case of the KDX motor, but since its in a non load bearing surface the cuts are trivial. You could reuse the KDX swingarm (I've heard of it being done, but have not seen it) but you would need to machine collars for the KX swingarm pivot points due to the smaller diameter swingarm bolt on the KDX. Actual build time on my hybrid was only somewhere around 10 hours (a chunk of that was practice welding on the old KDX donor frame). Plus you gain benefits with the KX chassis, most notable a removable rear sub frame (bend it on the KDX and you're in for major frame rework or replacement...I know, that's why I built a hybrid). Plenty of folks have done what you suggest, KX front end swap, KX style fenders. Fitting the saddle and side panels would be a chore but could be done. The KX seat position is much higher than the KDX, and missing the lounge chair slope that locks you up against the tank which helps make the bike feel more nimble. In the end people don't build hybrids to avoid the work of assembling it, and building one isn't for everybody. Having grown up on KDX's tho, given the chance again (which is coming for my son's bike) I would do it again without hesitation, I just enjoy riding the hybrid so much more than my trusty old plain KDX.
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diymirage
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Re: other options for kx/kdx hybrid- take a look

Post by diymirage »

if you do decide to build a hybrid be sure to install a chain on it or it will only sit there and look good ;)
De250r wrote:here's my latest build. 84 aircooled in a 2005 kx250f chassis. Very easy hybrid reallyImage

newbbewb wrote:DIYmirage has it right.


-1996 KDX 200 woods weapon (converted to 99 green body)
-1996 KDX 200 plated street toy (barney edition)
-2003 Yamaha TTR125-L (wifeys bike)
-1997 KDX 220 project bike
De250r
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Re: other options for kx/kdx hybrid- take a look

Post by De250r »

Just think tho it will always look that good ;)


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bufftester
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Re: other options for kx/kdx hybrid- take a look

Post by bufftester »

And the front brake could come in handy, tho dangling like that you could use it to tie the bike to the trailer lol
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Re: other options for kx/kdx hybrid- take a look

Post by De250r »

U toss it out like an anchor to grab whatever.


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diymirage
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Re: other options for kx/kdx hybrid- take a look

Post by diymirage »

On the bright side...if you dont put on the chain you wont need to fix the brakes iether
:lol:
newbbewb wrote:DIYmirage has it right.


-1996 KDX 200 woods weapon (converted to 99 green body)
-1996 KDX 200 plated street toy (barney edition)
-2003 Yamaha TTR125-L (wifeys bike)
-1997 KDX 220 project bike
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