Four wheeled bikes

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?

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).

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.

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.

Jayw900 said:

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?

Click to expand...

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.

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!

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

We had a thread where imaginations went wild. https://endless-sphere.com/forums/viewtopic.php?f=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/

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.

Jouta Quad can be ordered with assist.

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-Off-Road-500watt-Mid-Drive-Motor-Fat-Tire-Aluminum-Alloy-Recumbent-Quad/32957203039.html