View Full Version : The XR650 Project....

carmen cafro
02-01-2008, 09:19 PM
I am a new member and looking for some feedback on my project. I plan to make an XR650 trike. I have already built XR650 and CR500 powered quads and I assure all of you that the XR will smoke the CR and it won't rattle your brain in the process. This is mainly due to the incredible bottom end traction of the XR. The engine is counterbalanced and has almost no vibration.
Of course I would prefer to have the geometry of a 85 250r but due to the engine size, that won't be possible. It is around the size of a 350x. My original plan was to put it in a 350x frame but the need for large radiators and a large oil reserve stopped that. After doing some measuring on the stock aluminum XR frame, I found it to be within a 1/2 inch of the 350x all around, and using the same rake too.
My new plan is to leave the XR engine in the stock aluminum frame (which has an oil reserve in the frame) then fab wider triple clamps for the XR forks and a new swing arm using the stock rear shock and linkage, An after-market electric starter to solve the rearward kick starter problem, And an 06 or newer TRX 450 rear subframe which holds a battery for the electric starter. I'll use 250R plastic if the tank will work. I have attached some pics of the XR. Any feedback, guidance or whatever from members would be cool.

moose 53
02-01-2008, 10:27 PM
Hi carmen cafro ; Looks like a good project , I did a KTM 540 dirt bike you may find interesting. Look up http://www.3wheelerworldforums.com/showthread.php?t=51730 , http://www.3wheelerworldforums.com/showthread.php?t=60390 and http://www.3wheelerworldforums.com/showthread.php?t=58543 :Bounce

02-01-2008, 11:02 PM
Did you build the TRX680R that I see over on Glamisdunes.com?

Sounds like a good project either way.

02-02-2008, 12:38 AM
yes yes yes...ive seen these bikes in action in glamis...let me tell you they are ass handers.

i stick up for the new trx700, the motor is going to be a POWERHOUSE!

carmen cafro
02-02-2008, 12:49 PM
No that's not my 680 on Glamisdunes.com but I will post a pick of my quad as soon as I find it.
Hey Moose, I checked out your 540 conversion, Wow! That thing must be incredible in the sand. Who did the triple clamps for you? I'm looking for someone who can make some for the 650.

02-04-2008, 08:38 PM
look up tri-star triple clamps here in MA, im pretty sure if you send them the mesurments they will make you a custom set.

02-04-2008, 08:51 PM
mud dog has a 350x with a xr 600 engine not sure if it is the same engine or not but he might have some usefull tips

carmen cafro
02-04-2008, 09:16 PM
Thanks for the suggestions on the triples. And I've checked out that XR600 conversion. It's bad ass. The big difference is that the 650 is counterbalenced and watercooled. Attached is a pic of my 650 quad.

02-04-2008, 09:45 PM

that thing looks like it sucks! LOL just kidding man whoa...

is that a 450 frame? how is it on gas?

VERY sweet ride man let me swing a leg over it? ha

carmen cafro
02-04-2008, 10:36 PM
It's a 400ex frame. It can do about 70 miles on a desert tank. It's cool but it has one too many wheels. Next time your in San Diego, take it for a ride.

02-04-2008, 11:32 PM
Nice quad! Looks top notch!

carmen cafro
02-05-2008, 09:16 PM
Here is a pic of my CR500 quad conversion from when I first did it in a stock 250R frame.

02-06-2008, 01:07 AM
hmm you continue to impress me daniel-son.....:beer

you still have it? a friend of mine had a laegers short track CR5'hundo that i rode in practice with...i dont think my eyes have found their sockets yet.:naughty: that was even after it was "balanced" by crankworks. how was the vibro on that one? how much suspension travel does it have? 2 years ago i rode a friend of mine's CR500 bike in glamis ALL day. i have never been a 2 stroke guy but that is one 2 stroke i would love to own some day.

sorry to ask so many questions lol, you just have some sick chit!! you built the bikes we ALL wish honda would:w00t:

carmen cafro
02-06-2008, 01:31 PM
Sold it! The vibration could kill a small animal. Crank balancing makes no difference. It had 14 inches of travel. (it was a Baja Race quad) You don't want one, It will be just like a wife: A constant pain in the rear with a few moments of pleasurable riding. Build something else that has a counterbalencer. I hear that you won't have all the problems if you make a 500 trike.

02-09-2008, 02:18 AM
It's hard to keep an eye on, but sticking as close to the stock geometry of a trike (either a 350X or 250R) will greatly help. My XR600 trike has horrible rake, and I had to shorten my swingarm to make it more rideable. Overall, it's about the same length as my 350X, but it's long in the front and short in the back so it rides like crap. Also, the pegs are really low to the ground so sometimes your boots will dig into the sand (which hurts when you come down from a wheelie in fifth). It sounds like you will have a good start since the frame you'll be starting with has the same rake. I'm not sure if it's still on here, but you can probably search for ATC600X and find my trike. If you have any questions please ask, I'd be happy to help. I don't get on here much, but it's always good to see people doing cool things with trikes. My current plan is to swap over my 600 engine into a normal 350X frame, which will require a ton of work though...Good luck,

02-17-2008, 11:57 AM
My hat goes off too ya,It's a deffinate sick build.My beef is using a 350X frame..I really think you should go with the intended frame being the stock 650 frame and modding from there.In my opinion the 350X frame's,especially the '85's could'nt hold up and cracked,and too put in a torqe monster of a motor just does'nt seem practical.I personaly love my 600X and would have changed some stuff but not alot.And with the rake,I went with a Older R tripple that broght it in a few degree's and by the time I extended the swinger,it balanced out almost perfect.Keep us informed,and let me know if ya have any question's ..

02-21-2009, 10:30 PM
Bump for that sick 500R.

carmen cafro
01-30-2011, 10:49 AM
No more theorizing. Started work on the SwingArm. Wanting to keep the basic geometry of the motorcycle and being inspired by RedRider's extended aluminum swingarm, I decided to mate a stock 05 TRX arm to the stock XR arm. Since the shock linkage point is way toward the front of the XR arm, the decision was made to cut the motorcycle swinarm right behind the linkage mount. This way, the stock rear suspension would not be altered. Then after deciding the overall lenth of 21 1/2in, We were able cut the TRX arm to the correct length for the union. There was some milling involved to get a nice fit. The next step will be to weld the two arms together and then some serious plating. I should note that the work is actually being done by master fabricator, Warren Roll, father of Doug Roll (Roll Design). The fixture is Doug's actual TRX swingarm fixture. I will post some more picks after the arms are welded together and plated.

carmen cafro
03-16-2011, 06:26 PM
Here is the arms after they have been welded. I'll post more pics after the box plating is done.119694119695119696

carmen cafro
03-30-2011, 10:55 PM
Here are some pics of the finished swing-arm before powder coating

Louis Mielke
03-31-2011, 08:39 AM
Can't wait to see this bike together!

big specht
03-31-2011, 12:18 PM
The arm looks good keep up the good work

carmen cafro
03-31-2011, 05:35 PM
Thanks, I'm on to the triples

03-31-2011, 06:12 PM
I am subscribing to this thread! Looks like a cool build.

03-31-2011, 06:14 PM
I am subscribing to this thread! Looks like a cool build.

Me too....

07-23-2013, 03:28 PM
did you ever finish your build ?

01-06-2015, 02:07 AM
Really nice project! Can't wait to see more.
207294here's my Polaris Predator 500 conversion