KDXRIDER.NET

So Hybrid you used the reamer all by itself?? No drilling. Hmmm thats good to know as I will be doing a hybrid soon.

80elkster wrote:So Hybrid you used the reamer all by itself?? No drilling. Hmmm thats good to know as I will be doing a hybrid soon.

I did use drill bits to scale up till it was close to 17mm and then used the reamer.
Was just surprised the reamer went through easier then the drill bits.

Hi, it's my first post in this forum....i've got an '04 cr125 frame and i want to build a hybrid too.....what about the lining of the sprockets??

thanks!!!

there's a few CR hybrid post in the hybrid section you should check it out.
welcome to the site.

thank you....i was reading about che cr hybrids but noone wrote nothing about the sprockets....so i guess that they are ok....

market wrote:Hi, it's my first post in this forum....i've got an '04 cr125 frame and i want to build a hybrid too.....what about the lining of the sprockets??

thanks!!!

welcome, market!!!

I am building a hybrid with a CR125 chassis also. To get the motor mounted with the sprockets in line you need to have your swingarm bushings cut down to 47mm in length, I believe that they are 54mm and 59mm on the stock bike. Once you bore the hole in the cases to 17mm you'll have the rear of the motor set.

thank you so much chopper!

both of them have to be milled at to 47?

which year is your bike? mine is a '04 and as far as i know the from '02 to '07 the frames and swingarms are the same....am i right?

thank you! and sorry for so many questions.....

Yes both need to be 47mm, 02-07 are the same, mine is an 07.

chopper wrote:Yes both need to be 47mm, 02-07 are the same, mine is an 07.

Hi, mine is an 03cr125.
No problem with alignment.
In fact the bottom factory frame motor mount and the bottom kdx motor lined right up perfectly after you slide the swingarm bolt through.
Had to shave the welds on the front of the frame to clear the powervalve covers, and cut the swingarm bushings as specified, but thats it. The only mount that required modification was the front motor mount.

A freind of mine who recently done and 04 KX125 conversion has had trouble with sprocket alignment.
He says the motor a little low and that the chain needs to be run excessivly loose and he is not comfortable with that.
I was wondering if anyone else has had this problem with the kx builds.

hybridracing65 wrote: A freind of mine who recently done and 04 KX125 conversion has had trouble with sprocket alignment.
He says the motor a little low and that the chain needs to be run excessivly loose and he is not comfortable with that.
I was wondering if anyone else has had this problem with the kx builds.

I didn't have that problem with the two '04 KX builds I've done. I didn't even bother using the KX chain specs due to having a different engine in the bike. To get the right chain tightness, I followed the procedure where you remove the shock and then rotate the swingarm to get the c/s sprocket, swingarm pivot bolt & axle bolt all in alignment. That is where the chain is the tightest. Then you adjust the rear axle to get a certain % (don't remember what that is off the top of my head) of free play.

I've had no issues with prematurely wearing out the chain slider on the swingarm.

Do you know if your friend aligned the c/s to swingarm bolt first, and then dealt with the mounts and pipe & airbox positioning last?

thank you guys!!!! another question......in your hybrids did you use the kdx or the cr (or kx) silencer? probably the kdx-one qould be better cause it's longer....right?

(as far as i know a longer silencer means a quieter bike and with some torque added in the low-midrange)....am i right?


thank you again and sorry for my bad english!

You can't re-use straight up the KDX silencer. I did, but had to modify it heavily to fit (shorten the can 1.5-2 inches to clear swingarm and custom make the tube connecting to the expansion chamber ... lots of $$$ since I don't have a welder)
Most get a stock KX 250 silencer, it usually fits the KDX expansion chamber since the 125 is too small.
Don't know about the cr conversion.
Bad english? where u from?

thank you so much!!

i know that the kdx silencer won't fit immediately....but if i use a kdx pipe, why have i to rebuild the tube that connects the silencer to the pipe? it's not enough just to bend it? obvioulsy i think that the mounting holes on the silencer probably have to be rewelded in the right place to match with the frame mounting holes...


by the way.....i'm italian.....

the length and bend are totally different. and yes you'll most likely will have to relocate or fabricate some new mounts (easy).

Italian? your english ain't too bad, I used to live in France over 10 years ago, we were almost neighbors

I am using a KDX pipe and silencer on my CR/KDX hybrid,FMF desert/FMF tubine coreII.

Tedh98 wrote:

hybridracing65 wrote: A freind of mine who recently done and 04 KX125 conversion has had trouble with sprocket alignment.
He says the motor a little low and that the chain needs to be run excessivly loose and he is not comfortable with that.
I was wondering if anyone else has had this problem with the kx builds.

I didn't have that problem with the two '04 KX builds I've done. I didn't even bother using the KX chain specs due to having a different engine in the bike. To get the right chain tightness, I followed the procedure where you remove the shock and then rotate the swingarm to get the c/s sprocket, swingarm pivot bolt & axle bolt all in alignment. That is where the chain is the tightest. Then you adjust the rear axle to get a certain % (don't remember what that is off the top of my head) of free play.

I've had no issues with prematurely wearing out the chain slider on the swingarm.

Do you know if your friend aligned the c/s to swingarm bolt first, and then dealt with the mounts and pipe & airbox positioning last?

Yes he set the motor in and used the swingarm bolt but he set the motor in and i think looking at most other things for alignment first such as pipe alignment, headstay clearance, tank clearance.
He has also changed his suspension link tring to get the pegs and gnd clearance higher.
he is getting premature slider wear so he has went so far as to have swingarm bolt hole welded and then relocated the hole and remachined for allignment.
Crazy stuff!

For the later posts about silencers. My pics are old but I ultimately used the kdx knarley pipe and kdx silencer on my CR.
Most guys i know use kx 250 silencers on the kx hybrids.

Wow, sounds like your friend truly has a one-of-a-kind hybrid. I'm guessing that suspension link is the biggest single source of his problem. On the two '04's I've done, everything basically fell into place. I only ran into tank clearance problems when I put the oversize tank on.

Tedh98 wrote:Wow, sounds like your friend truly has a one-of-a-kind hybrid. I'm guessing that suspension link is the biggest single source of his problem. On the two '04's I've done, everything basically fell into place. I only ran into tank clearance problems when I put the oversize tank on.

Well he managed to keep both his head stays and he has had no tank mounting issues and he is running an oversized tank so most of his problem is in engine placement.
Heck he even managed to fit 09 450 rad shrouds!
i agree with you on the link.
I think thats his main source of chain slider wear.

Note to self, if I do a hybrid, use an 02 and up cr125 chassis...