What street-titled frame to start with?

[Chromer]

The Mission: An unstressed 65hp+ dual-sport do-it all. Singletrack-capable, to gravel road stormer, to interstate-sufferable

The motor: The parallel twin out of a Ninja 650. They're cheap, light, make decent power, and there are a bazillion of them out there, including lots of cheap crashed ones.

The suspension: TBD. I do like the KYB forks in my girlfriend's KLX250 quite a bit. (No, I'd go get my own set...)

The frame: This is the big question. Needs to have a street VIN. Preferably not too heavy, not too large, with a reasonably decent subframe. Major bonus if I don't have to cut & weld too much to shoehorn the motor in. Additional bonus if I don't have to heat-treat the whole thing after welding (ie, not cromoly).

Goal weight: 350lbs, +/--...


Thoughts? Off the top of my head... DRZ-400, DR650, XR-650L seem like likely candidates. Older KTM EXC something or other?

Anyone have the rough length/width/height of a 650R motor, offhand?


The timeline? Couple of years, I'm sure. I already have too many projects, but this is a bike I, y'know... NEED...

[itsatdm]

You and every Sam, Dick and Repsolrider have been thinking about this:
http://www.advrider.com/forums/showthread.php?t=640772.

[wheatwhacker]

If I had the time and the money, I'd put a Jap motor into a KTM frame. Here you get the best of both worlds.

[dentvet]

Its been grafted into a KLR and an Aprilia frame so far as I know. The stumbling blocks are the throttle bodies that interfere with the top tube and the placement of the counter sprocket which forces you to lower the engine in the frame. This is further complicated by the low hanging sump.

I think the aprilia worked because it was designed for a vtwin motor. I wonder if the kawasaki dirt bikes with perimeter frames might work? KLX650R or C for example. trellis framed street bike frames might work; sv suzuki, wrecked ducati?

Grafting the motor into a bike with a stout linkage type suspension would be great. 350 pounds will be a good challenge as well.

[itsatdm]

It has been tried with a KTM frame, though I can't remember if it was the 640 or some other, required a lot of frame hacking and the project died.

The KLX engine compartment is smaller than the KLR. It is a perimeter frame with dual tubes on top. Never measured, but just eyeballing it tells me it will not fit.

The KLR is a big thumper with a frame to match, and it still requires frame mods.

I have thought of doing something like this using the ninja frame. There are now some thumpers with the trellis frame.

One drawback is the placement of the rear spring and the limits placed on rear suspension travel. Possibilities are grafting on a dirt swing arm and relocating to spring to a conventional location. Or modifying the stock location of the rear spring attachment points to allow a longer spring. Or lengthening the swing arm to get more travel with the stock spring length.

Then there is the issue of front geometry. All of course, are major mods and will change geometry and requires some skills.

[TypeSH]

Do a search on the memeber jdrocks. He has a stripped down versys/ninja 650 that would meet your criteria.

[sailah]

My bike meets a few of your points but obviously more biased to street.

I planned on doing it to the ninja but went in a different direction.

My advice is this. Get a crashed bike with the frame too. You'll spend a ton of time and money to adapt a frame to a motor plus now you need to redo the wiring harness, hope the cs sprocket lines up, interference etc.

I had a ninja 650 wrecked and it's a great candidate.I know for certain that a ktm 950 swingarmwill fit the frame, itneeds to be shimmed though. I don't know how the sprockets will line up though.

I thought I could do a full transformation on the cheap. It may be possible, but the further I got into mine, it isn't. The suspension is a bitch. Trying to get a dirt bike front end sprung for the increased weight is hard trust me. I had 3 complete yz450 front ends and a set of ohlins and ended up going with the 950 front end due to not being able to get heavy enough springs. Plus the spokes are puny, brakes aren't up to the tsk so then you get into super moto stuff which is expensive.

I bought my bike for $1500 with a titled frame and easily went over $6000. At that point why not buy the bike you want and save yourself 3 months of hard labor?

Not trying to talk you out of it. I had a blast do in g mine, but once you get into it you'll see it ain't easy.

With a 650 you might get away with dirt bike suspension but I think it's pushing the limit of what a 400# bike with twice the hp is capable of.

Id buy a wrecked 650, part out what you don't need and then find a swingarm to match. Or cut the ninja arm and weld in a mount for a dirt bike shock. You might need to stretch it though

[Chromer]

Thanks sailah. I'm not planning on it being a budget build. If someone made a light DS with a powerful-but-unstressed motor, I'd be on board, but we either get racebikes with lights (Aprilia, KTM) or heavy non-singletrack-fun bikes (GS, SuperTenere), or some combination of light with a tradeoff of power vs. stressed.

I want to choose all 3: Light(ish), power, reliable. So understood, cheap will suffer.

And maybe the motor is just physically too big to deal with. The GS500 motor should probably be on my radar too.

[tbirdsp]

http://www.rallytwin.com/

[sailah]

Originally Posted by tbirdsp

http://www.rallytwin.com/

The 650 motor is lighter smaller and more power than the 500 plus fi

[tedesco886]

Did you read my recent thread?:oP sounds like what I want to do...I have a street plated XR650R rolling chasis (siezed the engine) in supermoto trim and have been looking for a ninja 650r engine to put inside...

[sailah]

Originally Posted by Chromer

Thanks sailah. I'm not planning on it being a budget build. If someone made a light DS with a powerful-but-unstressed motor, I'd be on board, but we either get racebikes with lights (Aprilia, KTM) or heavy non-singletrack-fun bikes (GS, SuperTenere), or some combination of light with a tradeoff of power vs. stressed.

I want to choose all 3: Light(ish), power, reliable. So understood, cheap will suffer.

And maybe the motor is just physically too big to deal with. The GS500 motor should probably be on my radar too.

Hey I'm totally rooting for you. Bless you for trying it's a total undertaking. The reward of doing it can't be monetized.

The motor is ideal no question. I think using everything you can from the donor bike will make it 100% easier. Have fun

[Ogre_fl]

If budget is not a huge concern, I think the Kawasaki 650 twin might fit in a BMW X-challenge frame.

I was surprised how HUGE the rotax engine is for a single.
I even wonder if the engines are close in weight.

You would still need to fix all the shortcomings of the BMW, like crappy suspension, wheels/rims, seat, fittings and bearings along with the tiny tank.

Best would be if you could find a wrecked one so you have to replace the forks and wheels/rims anyway.

[johnwesley]

it will be fun and expensive, and it will take a lot longer than you think. The front springs will be custom wound but that is only like 150 dollars for them. so that is easy just make sure that you use the spring ID as a measurement. Jd rocks has one that is neat and probably as cheap as you can get.

if you budget is no concern then get the motor and ship it to BTR moto and they can build you a frame with the rear suspension you want to your specs. They are very reasonable on prices. He did my off-road sportster swing arm

[SamM]

Chromer! Please PM me!

SamM