Dune Buggie Ultralight single seat

Ben800

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It is 95% new

460cc engine almost no original parts, setup at 36hp and a lot of torque at low RPM.

CVT comet 103 transmission and under transmission from Polaris Fugi generation (Japan) Hi-Lo Reverse- neutral



What is special and new (at least I have not seen it on the market) The engine, transmissions, fuel tank, cooling, exhaust, carburation, brake are assembled on an independant module. The transmission is supported by the engine to save weight. So to remouve everything there are 6 bolts, an electrical connector, a brake cable, accelerator cable and the decoupling chain.

So the majority of expensive components on one vehicle could be installed in another vehicle in less time than it takes to install tracks on a dirt bike. But this configuration has generated headaches in the positioning of this large propulsion block, the play is almost zero between the shock absorbers, the side panels and the rear tires. There had to be some space left to remove the clutch without removing the entire block. When the suspension is pushed in, there is almost no space left in all directions.





Deviation of the chain to pass it precisely in the pivot axis of the suspension, so that the tension of the chain does not change with the travel of the suspension.





It weighs 415lbs with liquids so like a 450cc competition atv bike Consider that there is a much longer wheelbase, all the panels and a roll bar ...

And despite its modest power compared to today UTV, SXS , it is 3 to 4 times lighter. No need to winch, lift with one arm.



The structure is based on thin steel tubes and triangulated from everywhere.

I’ve experienced ultralight aircraft fabric in the back, hard to have lighter liner than that. The resistance and amazing compared to the thickness, impossible to broke it with a hammer. Must say that some accounts on a thickness of this small canvas to fly very high in the air.

Imitation carbon fiber on the side, (to save a $ 1400) vinyl stuck on the thin abs. No rigidity, but since it’s only overlap, it’s not a big problem.

The handlebars instead of a small steering wheel can be curious, but I like the faster and direct driving of a handlebar (1/4 turn and we have full steering) when the terrain is very rough, It is easier to hold the rotary accelerator steadily than a pedal under the foot.
Adjustable steering damper



Independent suspension before shock absorber with adjustable rebound, several positions possible for the head of the shock absorbers in order to change the height, multi rear link with air shock absorbers still, several positions possible in order to change the height of the vehicle without changing the hardness of the preload.

Deviation of the chain to pass it precisely in the pivot axis of the suspension, so that the tension of the chain does not change with the subsidence of the suspension.



It will mainly be used to cover small wood trail, where the width and suspension are more useful than top speed. The height is also limited to pass under maple tubing.





I would like everything to be perfect at the exit of the garage, but big problem, the chain escapes the slightest acceleration

With the very large torque of the engine at low speed, reduction of the transmission, there could be 5670 lb of tension on the chain in LOW mode. This would cause a deflection of 10.5 ’’ on the 1 ’’ steel axis due to the almost central positioning of the socket. Instead of strengthening everything, enlarging the shifts by a lot and increasing the inertia in rotation by a lot, I made an adjustable tension arm that moves on the same axis as the chain and the suspension.

No need to take anything apart. The bending is now tiny.































 
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Ben800

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First field test.

Some small adjustment on the suspension and front steering.

Very comfortable.

The engine does not force at all even on hills and this has 5000 RPM and less. The LOW transmission speed would not have been necessary due to the torque already present at 2000 RPM.

I was lucky to fall right away with perfect ramps in the clutch (home made arm) for the force-RPM of the engine I used all the space available in the clutch












https://www.youtube.com/watch?v=oc_HIXDjL2o&t=1s
 

mckutzy

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This is cool....

I however, dont know how long those rear pillow block bearings are going to last, as they arent meant to be used in a dynamic manner like that... Yes they can be used to support a shaft in a off degree manner from there base angle, but in a static state, not as a moving articulated joint.

Also what kind of brake disc is that?? from a bicycle???
Unless that is a bad camera angle eye trick, that looks like the disc is bending while the axle is moving at an angle....Ie the caliper/bracket is not congruent with the axle during movement...????

Other than that its pretty cool looking machine...
 

Ben800

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The pilow bearings are not sold for this, but physically speaking, they are spheres which swivels in another sphere with grease between the 2. like all the ball joints of suspension and drive. The tilt speed is tiny compared to the rotation speed. No reason that it wears out super quickly.
The brake on the axles is an emergency brake, the effective brake is on the transmission, with my multiplication of the ratio of sprocket and transmission, it's like having a 54 '' disc on the axles . The small brake disc on the axles is flexible and takes its place.

The whole is much lighter than a double wishbone suspension and drive shaft.
 

Kartorbust

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You never want to run the main brake off of a jackshaft, always on the spool/axle. If your chain snaps, you will lose all braking. It's fine to have an emergency/parking brake, but ideally you should have your main brake on the axle. You can still utilize a single rotor and have two calipers on there for an emergency brake and regular brake, if you have the room for it.
 

Ben800

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You never want to run the main brake off of a jackshaft, always on the spool/axle. If your chain snaps, you will lose all braking. It's fine to have an emergency/parking brake, but ideally you should have your main brake on the axle. You can still utilize a single rotor and have two calipers on there for an emergency brake and regular brake, if you have the room for it.
All ATV Polaris with drive chain have the brake on transmission for more braking power while being more sheltered from the elements.

All snowmobiles, until 2010, had the brake on the transmission before the chain, with no other brake.
 

Kaptain Krunch

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All ATV Polaris with drive chain have the brake on transmission for more braking power while being more sheltered from the elements.

All snowmobiles, until 2010, had the brake on the transmission before the chain, with no other brake.
Polaris ATVs with transmission mounted brakes are not the best design, as mentioned. if the chain breaks,you dont brake. The reason they are able to get away with this setup, is they are equipped with front brakes. Your machine does not appear to have fronts (although its hard to tell from pictures).

As far as the pillow blocks, I hope they work out for you. the way i ride my toys, i would be very cautious of that rear suspension setup. especially twisting the chain the way it does during articulation.

Looks cool otherwise, and certainly looks like you have some time invested!
 

Kartorbust

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Polaris ATVs with transmission mounted brakes are not the best design, as mentioned. if the chain breaks,you dont brake. The reason they are able to get away with this setup, is they are equipped with front brakes. Your machine does not appear to have fronts (although its hard to tell from pictures).

As far as the pillow blocks, I hope they work out for you. the way i ride my toys, i would be very cautious of that rear suspension setup. especially twisting the chain the way it does during articulation.

Looks cool otherwise, and certainly looks like you have some time invested!
Post 3, 5th picture down has a clear shot of the front, no brakes up front, from my view at least.

Redundancy is nice for braking. What works on one thing, doesn't always mean it will work on another or it was a good idea. When it comes to brakes, there should be next to no compromises. It's a safety thing. It is your buggy, we are just giving constructive feedback.

Anyway, what size tires you have on it as well as what wheels/bolt pattern? What was the donor vehicle for these parts?
 

Ben800

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Post 3, 5th picture down has a clear shot of the front, no brakes up front, from my view at least.

Redundancy is nice for braking. What works on one thing, doesn't always mean it will work on another or it was a good idea. When it comes to brakes, there should be next to no compromises. It's a safety thing. It is your buggy, we are just giving constructive feedback.

Anyway, what size tires you have on it as well as what wheels/bolt pattern? What was the donor vehicle for these parts?

There are only Ball joints from an old Suzuki ATV. The A arm and the hubs are completely transformed. The wheels are light and wide wheels which are designed to go backwards, it was very difficult to fit the steering pivots in the wheel (4.5 '' inside diameter) to have a good quality of driving, when the wheels are deported outside the rotation joints, the driving is awful in the bumb.
I don’t like to use old ATVs to build something else, it’s often a problem because everything is worn out, it’s not optimized for the new vehicle we want to make, and the style suffer. Build what is buildable as much as possible and buy standard industrial new parts.



I already have my emergency brake in the axle just or in case of a brake or transmission failure.

I have already tried a double piston hydraulic brake with a medium disc on the rear axle on another vehicle and the braking power was too low compared to the power of the tiny brake on the transmission. Who can block the tires.



On my construction last summer, there are very small brakes at the front (manufactured because of the regulations) but you should not feel used at these speeds because it is crazy dangerous. This required a giant rear brake disc.


http://https://www.youtube.com/watch?v=08rI0q4KtWA

http://https://www.youtube.com/watch?v=08rI0q4KtWA


https://www.youtube.com/watch?v=9TjydhoHasU

https://www.youtube.com/watch?v=08rI0q4KtWA

 

Ben800

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Same short hike twice in a row with the DB460 and the BW208.
The DB460 is quite quiet, no vibration, no crackle or suspension noise, no transmission noise only a rolling noise at good speed. Very comfortable with the flexibility of the suspension (especially at the rear you can feel absolutely nothing) and the wheelbase long enough (about like a 2-seater ATV)
The position of the camera which is too high above the helmet, is too far below the helmet due to the relaxed riding position.
The BW208 is extremely manoeuvrable and lively with its high clutch point, but slower top speed, still ample for small, narrow and winding paths.

 
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