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cop292
09-18-2006, 08:58 AM
I was fortunate enough to get a 2003 KTM 525 EXC for a great deal. I am considering turning it into a hybrid. I have several mx bikes and quads but have never built a hybrid before so I am lost as to which frame to use, etc. I would like to avoid as many pitfalls as possible during the build. Any opinions and advice would be appreciated.

jonboy
09-18-2006, 03:59 PM
IMO opinion you cant go wrong with an 250R or 400ex frame

protraxrptr17
09-18-2006, 06:16 PM
An '86 250R frame would be the easiest because of the open swingarm. It would still be alot of work. There is really nothing easy about it. I have seen some conversions that just stick the engine in front of the swingarm, but that causes problems with how the rear suspension works under load from the chain. My Raptor conversion was very tough and took alot of trial and error and fabrication. One bad thing about the stock 250R frames is the square tubing is a pain to work with. Any way you go you are going to be a huge undertaking.

cop292
09-18-2006, 06:19 PM
How does the 525 do in a quad frame??? Is it worth the trouble?

downeyballz
09-18-2006, 07:27 PM
just buy the walsh 250 frame that comes with ktm 525 mounts. then you will have a top quality frame thats super strong and will have correct geomerty.

http://www.wrcracing.com/shop/index.php?main_page=product_info&cPath=25&products_id=31

jrspawn
09-18-2006, 08:04 PM
The Walsh KTM chasis is your best bet. The correct fit and geometry so you dont have to worry about something not working. Also like mentioned before, you will see alot of hybrid conversions that bolt the engine infront of the pivot area, this is not a very good way to mount the motor, the angled that it sits it at and most of the time lowers the engine down too far which having the drain bolt that low isnt good. Plus if im not mistaken the frame rails will be a good bit too low for the ktm motor in the r chasis, if at all it would work, you would prob. have to pitch the engine too far with out major modification.

2muchquad
09-18-2006, 09:38 PM
why pay all that money for a frame when a 400ex chassis will do,are you racing pro?

jrspawn
09-18-2006, 09:53 PM
Yeah a 400ex frame might work fine, but people have different prefferences on chasis. Is a 400ex as durable as a walsh or any other aftermarket frame, does it handle as good as a walsh chasis? I can tell you the ride difference between a 400 chasis setup and a walsh setup, i cant even begin to explain how much nicer than walsh is, all i can say is you have to ride one thats set up correctly to understand:D Plus having an aftermarket frame that is specifically built and proven for the correct engine application, you get a better end result. Im not saying conversion arent good at all, i think some are pretty nice with the detail that goes into them, but alot of people prefer to have a chasis that is race proven, will hold up 100times longer and better than oem, and will handle like a rocket ship.

Justin

firefighterjosh
09-18-2006, 10:28 PM
I have heard of the C-dale guys putting the KTM engines into there chassis. C-dale frames are tough as nails

protraxrptr17
09-19-2006, 07:25 PM
Originally posted by cop292
How does the 525 do in a quad frame??? Is it worth the trouble?

Oh yeah, it's worth the trouble. Nothing will pull like a 525. I don't know about the EXC version, but my 525SX is a beast. Top quality sprockets and chain are a must. It has so much torque, it will destroy the cheap stuff in just a couple hours.

I agree that the Walsh frame would be the quickest, but that's too much money for most of us. If you have access to the right tools, and have the right skills you can put it into any frame you want. I was told numerous times that it was impossible to convert my Raptor. I was also told it wouldn't handle right, and it wasn't worth doing. It did take lots of time, huge amounts of fabrication, and many hours of just daydreaming and staring at the frame and engine trying to visualize what had to be done. But now, after it's all done, I proved them all wrong. The engine alone will make a huge difference in handling because of it's light weight and high power. Just mount everything as low as you can, and get the engine centered from left to right and you'll be fine. I used a 250R axle to do this. It will center the engine perfectly. This detail is something that is usually overlooked. Start by centering the axle, THEN center the engine.

The Cannondale frame would be the hardest of all to convert. First of all, it's aluminum. Most people don't have the equipment to weld it. The frame is designed for a backwards engine. The swingarm is also backwards for a KTM RFS engine.

firefighterjosh
09-19-2006, 08:03 PM
Originally posted by protraxrptr17
The Cannondale frame would be the hardest of all to convert. First of all, it's aluminum. Most people don't have the equipment to weld it. The frame is designed for a backwards engine. The swingarm is also backwards for a KTM RFS engine.

yes the cannondal is prally the hardest to do. But I beliver you can flip the axle and re weld the brake brackets

slipperyjake
03-23-2010, 10:41 AM
if you use a lobo 250r its aot of hard work it took me and my dad ages to do it. if you do just make sure that the center of the sprocket is in the center of the swingarm pivit bolt and keep everything as low as possable you will be fine!

here are some pics of our hybrid roll design lobo 250r with a ktm 250f


rolldesign lobo (http://s1026.photobucket.com/home/dougroll4/index)