TwinSpreeio! An exercise in stupidity.

[R1Titan911]

[pitobread]

Nice work. Engine is impressive.

I really like the way that seat came out visually... is it is comfortable?

Its not bad, I drove this thing for 3hours straight and I wasn't crying after. But you loose a bit of cushion thats for sure.

Thanks for all the kind words.

[Xxbeejay45xx]

Wow Wow Wow! That's very incredible. Dual 125cc strokers will be the thing to see next!

[Meatball]

Anyone can cram a big wild motor into a frame and make it all fit with custom mounts and brackets, etc....but actually MAKING a wider crankcase and longer crank is just nuts. Converting a single cylinder to dual?!?!? Bruh...

Whats next...4v overhead cams? Maybe Supercharge? How bout a jet engine? Flux Capacitor?

Its interesting that no matter how insane the motors get in these little bikes that you don't hear about more frame failures...maybe theyre tougher than I thought?

[pitobread]

No 4 valve anything! Supercharger... possibly.

[noiseguy]

Its interesting that no matter how insane the motors get in these little bikes that you don't hear about more frame failures...maybe theyre tougher than I thought?

You can definitely fail the Spree frame, with stock motor, taking it off jumps. I've straightened bent Spree frames prior with this type of damage. The way the motor is attached, structured, and develops power... you'll never fail a frame from motor... motor is its own structural element.

[noiseguy]

Ha! Found it.

Frame_straight_1.jpg (74.95 KiB) Viewed 16198 times

[Meatball]

Nice set-up there! Im assuming that once the tubular frame has been kinked, the integrity is compromised to the point of requiring the addition of a structural brace. Back in my dirt-jumping BMX Bandit days Ive seen many frames snap at the neck weld. A few bottom frame tubes snapped as well up near the neck area near the weld. Tons of bent/broken stems, forks, pedals and cranks. I have never seen a rear triangle fail. Our scooter frames are basically an "S" shape but the motor creates the stronger triangle in the rear. Makes sense now you pointed that out.

[noiseguy]

Im assuming that once the tubular frame has been kinked, the integrity is compromised to the point of requiring the addition of a structural brace.

I don't recommend taking Spree off jumps. Frame can't handle it, and cantilevered wheel and engine casting isn't designed for it either.

There's no tube "kink" per se in this kind of failure, whole thing's just folded up a bit and frame is stressed evenly; in this case handlebar was 2" too close to seat IIRC. If this scooter, once repaired like this, is ridden on road with normal size rider, it should never see this failure again. The real challenge is getting the right dimension... I had another Spree to measure at the time. Weak point is where tube meets the clamshell rear frame, and main bend at floor.

If main tube was visually kinked the handlebar would be at seat. In that case, I'd jack it out to same position and sister a tube over the kinked portion, welding the sister in place and taking it out of the equation structurally. Still wouldn't be strong enough for jumps but would be street rideable.

Braces are best for stiffening up frame for things like drag racing, maybe track racing.

[Meloshameless]

Thats a nice Norton in ur garage. Dont see to many of those out here.

[pitobread]

Its actually a terrible headache and only wearing Norton tins. CB750 with Aprilia running gear and Norton tins.

[pitobread]

....

[tazland001]

I just saw this build and I was like *. Pito you are da man. Best engine build by far I have ever seen on this forum.

Taz

[pitobread]

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[Meatball]

GOTTA get footage of the first rips. Cant wait to see that thing in action!