Four wheeled bikes

General Discussion about electric bicycles.
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Jayw900   10 µW

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Four wheeled bikes

Post by Jayw900 » Jan 30 2019 1:32am

I've had this account forever it feels like but mostly just lurk. Lately I've been toying with building a 4 wheel e-bike and did some searching but haven't found many people trying it out on the forum. I'm curious as to why that is?

dustNbone   10 kW

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Re: Four wheeled bikes

Post by dustNbone » Jan 30 2019 2:02am

One big thing is that a 4 wheeled vehicle doesn't meet the legal definition of bicycle in many jurisdictions. Usually the regulations specify 2 or 3 wheels. The 4th wheel makes it a car (legally speaking).

You might get away with it if it were unpowered, but making it motorized pushes it even more toward being carlike.

Another consideration is complexity. A trike has either a single driven wheel or a single steered wheel, so things only get complicated (with differential or steering linkage) at one end.

A quad needs both, a differential between the driven wheels (or single driven wheel on one side, scary stuff when you jack up the power) and a linkage on the steering wheels (plus the need to maintain alignment).

flat tire   1 MW

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Re: Four wheeled bikes

Post by flat tire » Jan 30 2019 7:59am

Probably because 2 wheels is drastically more fun in most situations. You get to balance and lean. A 4 wheel bike makes the most sense for cargo, or something like that.

chvidgov.bc.ca   10 kW

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Re: Four wheeled bikes

Post by chvidgov.bc.ca » Jan 30 2019 1:29pm

Usually too wide to fit on a bike path as well. The posts on bike paths to slow bikes down at road crossings seem to be set about 40 inches I think - that works well with my trike which is 32 inches wide, but I have to pay attention at speed, which is what the posts are for. That gives me about 4 inches clearance on each side when I whip through, focussing on the gap.

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amberwolf   100 GW

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Re: Four wheeled bikes

Post by amberwolf » Jan 30 2019 2:57pm

Jayw900 wrote:
Jan 30 2019 1:32am
I've had this account forever it feels like but mostly just lurk. Lately I've been toying with building a 4 wheel e-bike and did some searching but haven't found many people trying it out on the forum. I'm curious as to why that is?
Mostly legality. Unless you're only using it offroad (there's a number of those around here) then almost nowhere is it classed as a bicycle, or even listed in the definitions of legal vehicles. So you can't ride it on the roads without getting harassed, ticketed, confiscated, etc., anywhere that doesn't like unusual things happening. :/


There's a guy I see occasionally in my area that rides a homebuilt pedal-only quad, been around at least a year or maybe two, probably longer. Never get teh chance to talk cuz I'm always on my way to work or somewhere else time-sensitive when I see him. :(

I'd love to build a quad for cargo use, but AZ law says (essentially) they have to be built by a specific company that's licensed specifically for this, though it does not specify how to get such a license to build such things, so there's no process to actually do it. The only ones I've seen other than the guy above are large commercial ones at Encanto Park for touring the park itself.

markz   100 GW

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Re: Four wheeled bikes

Post by markz » Jan 30 2019 7:48pm

Just claim it as a mobility scooter, I saw a security guard puff out their chest eyeballing a hand crank mobility scooter, when the guy said its his mobility device, that shut up the guard quick!

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amberwolf   100 GW

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Re: Four wheeled bikes

Post by amberwolf » Jan 30 2019 11:17pm

Mobility devices are restricted to very slow (fast walking) speeds, and not on the roads. So useless for my purposes.

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Dauntless   100 GW

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Re: Four wheeled bikes

Post by Dauntless » Jan 31 2019 2:56am

We had a thread where imaginations went wild. https://endless-sphere.com/forums/viewt ... =6&t=96320 A lot of it was a bit much for our budgets or for building in the garage. Although the three wheel instructable I put up there should be within reach.

https://www.instructables.com/id/Three-Wheel-Bike-Car/
Any sufficiently advanced technology is INDISTINGUISHABLE FROM MAGIC!
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Jayw900   10 µW

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Re: Four wheeled bikes

Post by Jayw900 » Feb 02 2019 8:52pm

Yeah i thought it might have more to do with legalities for the most part. Around here i could probably play stupid since it's a fairly small town i live in. I figure if it looks like a bike and i don't go crazy fast it may work out.

Triketech   1 kW

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Re: Four wheeled bikes

Post by Triketech » Feb 02 2019 9:34pm

Jouta Quad can be ordered with assist.

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Dauntless   100 GW

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Re: Four wheeled bikes

Post by Dauntless » Feb 03 2019 12:58am

There's stuff out there, but is it really worth what they want? If I DID pay the $7k the 500w would have to go.

https://www.aliexpress.com/item/4-WD-Of ... 03039.html
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