Open rear end

[TrailerRider]

Were there any quads that came with an open style differential or just one wheel wonders?

Looking to build a street legal 3 wheeler but a solid axle would be no fun on asphalt.

Thanks

[fabiodriven]

The Kawasaki KLT250 (and maybe 200) had a selectable rear end. I'm not sure if it was a true differential or just a one wheel wonder when unlocked. I think it's a true differential.

As a street trike rider I have to say I like the regular live axle and wouldn't want an open differential myself.

[fabiodriven]

I was just thinking about it and I can see a problem with an open differential you may encounter. Any open differential rear end I can think of has two brakes, one on each axle. You're going to have to run two brakes if you're running an open differential, I can't think of any way around it. If an open differential rear end were to lose traction on one wheel during braking with only one brake, then the wheel with traction would immediately freewheel (no more braking) and the wheel without traction would spin in the opposite direction of travel. On a vehicle designed to lose traction on the rear wheels, our beloved three willers, the idea of a rear end that requires two firmly planted tires is not going to work out unless you have two rear brakes, which is feasible. I still wouldn't want a differential rear end though.

[TrailerRider]

Thanks for the information!

[TrailerRider]

The idea is to make a 350x into a street able trike. The reason I was thinking about the open rear is because a 350 on the street even with proper DOT street tires, seems (to me), like it might be a bare to maneuver around corners at slower speeds. All my experience on trikes is in the dirt so maybe its not that difficult with the proper tires? What kind of trike are you running and is it a solid axle?

Thanks

[fabiodriven]

My machine is made from an XR650L but a 350X should be comparable enough. Here's the thread for the bike.

https://r.tapatalk.com/shareLink/topic?share_fid=192465&share_tid=166302&url=http%3A%2F%2Fwww%2E3wheelerworld%2Ecom%2Fshowt hread%2Ephp%3Ft%3D166302&share_type=t&link_source=app

I got your private message and we can certainly connect on messenger, but I didn't want to leave this thread hanging.

If you look at the pictures of my bike, you'll notice it has little tiny rear wheels. There are multiple benefits to this on the road.

First, their small size and high pressure (roughly 20 psi) allows them to slip easily when you're trying to turn. They offer more than enough traction to bite when you need them to. Another benefit of their small size is less rotational mass, so it's easier on the clutch and axle bearings. Also a little less unsprung weight, which isn't a huge deal but it's another benefit to mention.

A bigger tire isn't necessarily a bad thing, but it's not necessary. Some people might like it but I wouldn't. I like the rear end of this bike to be as loose as I can get it, because if you're riding a wheeler fast you're steering it with the rear wheels. Bigger tires with more bite and sidewall will make it harder to pitch the rear end.

That's all at speed though. You mentioned low speed turning. At lower speeds you just use your body to unload the inside wheel and let it slip. You can take it right up off the ground if you need to. Just transfer your weight. Tight left, lean forward and right. Give your front and right wheel the traction and remove it from the left. I'm sure you probably already do this.

[ATC King]

Motorcycle trike conversions use a differential, but that's a horse of a different color.

They're much heavier, and I'd argue, more top heavy.



For a true 3 wheeler to licensed street prowler, things are going to be different. Either way, it's going to take more arm strength to handle the turns. Other than the brake problem, I could see lifting the inside wheel with a differential would cause some other problems. That would effectively stop power transmission to the road and cause a sudden deceleration condition in a turn, which could be very problematic.

Open differentials operate on the idea that all tires remain on the ground/pavement. A highway speeds, lifting a tire with an open differential would cause a sudden change in vehicle handling characteristics.

It's probably safer to have a wide axle, and tires that slip more while turning at high speed. The biggest drawback would be snow covered, or icy conditions. A solid axle is going to be all over the place at highway speeds. If the trike is low enough, it'll probably just spin out, but if it's got a high center of gravity, it'll be prone to tipping.

There's a lot of variables. The legal issues also come into play. Most states require a differential for motorcycle/trike conversions. If you can plate an ATC where you live, then it's something different. Legal, barely legal, or plain being sneaky, whatever you do, feel comfortable with it at speed or don't ride it.

[fabiodriven]

Most states require a differential for motorcycle/trike conversions. If you can plate an ATC where you live, then it's something different. Legal, barely legal, or plain being sneaky, whatever you do, feel comfortable with it at speed or don't ride it.

For years before I had a street legal three willer people said this to me. "It's illegal to run a live axle on the road." I couldn't find anywhere in the laws of Massachusetts that even mentioned a differential, and the safety inspection doesn't cover it either. Since discovering that I've challenged anyone who has said this to show me a law in regards to street legal three willers and differentials and not one person has been able to.

In regards to a live axle being trouble at high speeds and whatnot, they're not what you think. Our style of trike has a very light footprint which helps to minimize the detrimental street manners of a live axle trike on pavement.

https://youtu.be/0E3qVcYc0Ig

[ATC King]

Before I dump on the OP's thread, I'll offer a possible resource.

There are these Chinesium contraptions: https://www.aliexpress.com/item/32371517210.html

I don't have any idea of their durability or power handling capabilities, but they seem to be along the lines of what you're looking for. If you're wanting low speed and low power functionality, those may be an option.

The other option may just be to fashion a bearing hub for one wheel, so it spins independently of the drive, which will create it's own unique handling issues, like having a tighter turning radius in one direction and a larger one in the other, and pulling to one side during acceleration on pavement. I've got a mini chopper trike set up like that, and it's not ideal, but a solid axle wouldn't let it hardly turn at all because of it's extreme steering geometry. How much you'd notice any of it, will largely depend on tire choice and terrain.



Onto my reply:

All road legal vehicles fall under the category of motor vehicle, and the general laws, regulations, and rules applied to them.

There are exemptions of many types and more narrow definitions for specific motor vehicles, but it starts at the top and works down.

This is a federal example:

§ 85.1703 - Definition of motor vehicle.
(a) For the purpose of determining the applicability of section 216(2), a vehicle which is self-propelled and capable of transporting a person or persons or any material or any permanently or temporarily affixed apparatus shall be deemed a motor vehicle, unless any one or more of the criteria set forth below are met, in which case the vehicle shall be deemed not a motor vehicle:

(1) The vehicle cannot exceed a maximum speed of 25 miles per hour over level, paved surfaces; or

(2) The vehicle lacks features customarily associated with safe and practical street or highway use, such features including, but not being limited to, a reverse gear (except in the case of motorcycles), a differential, or safety features required by state and/or federal law; or

(3) The vehicle exhibits features which render its use on a street or highway unsafe, impractical, or highly unlikely, such features including, but not being limited to, tracked road contact means, an inordinate size, or features ordinarily associated with military combat or tactical vehicles such as armor and/or weaponry.

(b) Note that, in applying the criterion in paragraph (a)(2) of this section, vehicles that are clearly intended for operation on highways are motor vehicles. Absence of a particular safety feature is relevant only when absence of that feature would prevent operation on highways.

[39 FR 32611, Sept. 10, 1974, as amended at 45 FR 13733, Mar. 3, 1980; 73 FR 59178, Oct. 8, 2008; 75 FR 22977, Apr. 30, 2010; 81 FR 73972, Oct. 25, 2016]
AUTHORITY: 42 U.S.C. 7401-7671q.

CITE AS: 40 CFR 85.1703

https://www.govregs.com/regulations/title40_chapterI-i20_part85_subpartR_section85.1703

A differential is a safety device when two or more wheels on opposite sides of the vehicle, share the same axle. The best resource for the legality of motorcycle/trike conversions would be a trike group in the particular state. Some states consider anything with 2-3 wheels a motorcycle, others do not and require them to be registered as configured for current use. Massatucets even has a license restriction for anyone who passed their physical riding test on a three wheeled motorcycle or sidecar rig.

"A customer who takes a road test on a limited use vehicle or 3-wheeled vehicle (trike) will receive a Class M license with a “U” restriction with the following description:

“Motorcycle — limited use vehicle only” or
"Motorcycle — limited to 3-wheels only"
With this restriction, a customer will only be allowed to use the Class M license to operate a limited-use vehicle or a 3-wheel motorcycle."

https://www.mass.gov/info-details/road-test-requirements-for-passenger-motorcycle-and-commercial-licenses

Motor vehicle laws are all over the place, state to state, to county, to city, to incorporated towns. Federal, state, county, and city use of ATVs could have it's own thread.


As far as street legal 'three willers', that's next to near an impossibility for many, if not most people. Which still doesn't mean they can't be legally operated on highways. In Arkansas, I can't license/plate my ATCs, but there are still hundreds of miles of pavement I can legally ride on. That all comes down to this vague law:

"27-21-109.
(a) It is no defense to a prosecution under this chapter that the driver or operator possesses a
valid driver's license or motorcycle operator's license.
(b) It shall be a defense to prosecution under § 27-21-106 for a violation of operating an allterrain vehicle upon the public streets or highways if the all-terrain vehicle operator can show by
a preponderance of the evidence that:
(1) The public street or highway was outside the city limits of any municipality or
incorporated town in Arkansas;
(2) The public street or highway was not a United States interstate highway;
(3) Traveling on the public street or highway was the most reasonable route of access
available to him or her from one (1) off-road trail to another off-road trail or from his or he r
private property to an off-road trail; and
(4) His or her purpose for riding on the public street or highway was to get from one (1)
off-road trail to another off-road trail or his or her purpose for riding on the public street or
highway was to get from his or her private property to an off-road trail. "

https://www.cpsc.gov/s3fs-public/pdfs/blk_pdf_ArkansasLaw.pdf





There could be a thread dedicated to each state's ATV/OHV laws, including federal agency lands. Also incorporating information on street legal builds. That would be a very informative thread, if managed properly, with links to each state.

Other than that, I'm pretty certain there are a lot of trike riders on here, who know how they handle on pavement at high speed. :beer

[fabiodriven]

That's fantastic someone has finally shown something in writing. Kudos to you!

It seems you could get around the differential requirement in this case if you can show it's not required.

[atctim]

I too have a street legal trike - XR650L - with live rear axle from a TRX450R. There is nothing in the Pennsylvania vehicle code that mentions anything baout live VS open rear ends in the motorcycle section. After all, aren't all motorcycles equipped with live axles? PA defines a motorcycle as: A motor vehicle having a seat or saddle for the use of the rider and (1) designed to travel on not more than three wheels in contact with the ground, or (2) designed to travel on two wheels in contact with the ground which is modified by the addition of two stabilizing wheels on the rear of the motor ...

[big specht]

And what’s the chance the cop that pulls you over is going to bring up that issue anyways. Hell most don’t even know the bumper height law anyways most of these lifted trucks are over.

[ATC King]

And what’s the chance the cop that pulls you over is going to bring up that issue anyways.

Slim to none if they're a decent officer and the rider has the proper license/registration. Running proper street tires couldn't hurt either.


Riding something like that may likely get someone pulled over just to talk about it though. Anyone owning a street legal trike better be prepared for lengthy conversation every time they so much as stop for fuel.

[fabiodriven]

PA defines a motorcycle as: A motor vehicle having a seat or saddle for the use of the rider and (1) designed to travel on not more than three wheels in contact with the ground, or (2) designed to travel on two wheels in contact with the ground which is modified by the addition of two stabilizing wheels on the rear of the motor ...




This reads almost word for word the same as what Massachusetts said.




All road legal vehicles fall under the category of motor vehicle, and the general laws, regulations, and rules applied to them.

There are exemptions of many types and more narrow definitions for specific motor vehicles, but it starts at the top and works down.

This is a federal example:

§ 85.1703 - Definition of motor vehicle.
(a) For the purpose of determining the applicability of section 216(2), a vehicle which is self-propelled and capable of transporting a person or persons or any material or any permanently or temporarily affixed apparatus shall be deemed a motor vehicle, unless any one or more of the criteria set forth below are met, in which case the vehicle shall be deemed not a motor vehicle:

(1) The vehicle cannot exceed a maximum speed of 25 miles per hour over level, paved surfaces; or

(2) The vehicle lacks features customarily associated with safe and practical street or highway use, such features including, but not being limited to, a reverse gear (except in the case of motorcycles), a differential, or safety features required by state and/or federal law; or

(3) The vehicle exhibits features which render its use on a street or highway unsafe, impractical, or highly unlikely, such features including, but not being limited to, tracked road contact means, an inordinate size, or features ordinarily associated with military combat or tactical vehicles such as armor and/or weaponry.

(b) Note that, in applying the criterion in paragraph (a)(2) of this section, vehicles that are clearly intended for operation on highways are motor vehicles. Absence of a particular safety feature is relevant only when absence of that feature would prevent operation on highways.

[39 FR 32611, Sept. 10, 1974, as amended at 45 FR 13733, Mar. 3, 1980; 73 FR 59178, Oct. 8, 2008; 75 FR 22977, Apr. 30, 2010; 81 FR 73972, Oct. 25, 2016]
AUTHORITY: 42 U.S.C. 7401-7671q.

CITE AS: 40 CFR 85.1703

https://www.govregs.com/regulations/title40_chapterI-i20_part85_subpartR_section85.1703



After reading Tim's post, that made me think. These regulations you're citing, are those applicable to motorcycles? They said "motor vehicle". Are there different guidelines for motorcycles?

[fabiodriven]

The other option may just be to fashion a bearing hub for one wheel, so it spins independently of the drive, which will create it's own unique handling issues, like having a tighter turning radius in one direction and a larger one in the other, and pulling to one side during acceleration on pavement.

Also I would highly recommend against even considering this option for many reasons.

[ATC King]

After reading Tim's post, that made me think. These regulations you're citing, are those applicable to motorcycles? They said "motor vehicle". Are there different guidelines for motorcycles?

For street legal motorcycles, generally yes, but state laws vary when adding another wheel. With vehicles like the Polaris Slingshot, which was initially considered a three wheeled motorcycle in some states, those laws are being, and have changed in places. I suspect if that oddity became more popular, more states would draw a dividing line between two and three wheeled vehicles, likely with some exceptions for motorcycle based trikes and sidecars. Then there are those Can Am things, and other three wheeled vehicles like Morgans. Plenty of tri-wheeled conveyance options for someone with four wheel anxiety.

I own a platypus of the two wheeled world, a moped, which is designed so that it purposefully isn't a motor vehicle, therefore licensing and registration is minimal or nonexistent for road use. Instead, it is legally considered a motor-driven cycle in some places and not a motorcycle. Although, many of them can easily be built to reach and maintain highway speeds, but that also legally puts them into the motor vehicle classification and would require the proper licensing and registration.

I don't really care how someone goes about getting anything legal. If their state DMV passes it through, then it's legal enough. What I'm interested in is digging stuff up for the informational value. Some of this stuff isn't easy to find and state vehicle laws vary like state alcohol laws. Those ABC stores in Virginia seemed strange, and Utah, those crazy Mormons got other ideas too. Many parts of Arkansas are still dry, and several that aren't, don't allow sales on Sunday. BYOB for anyone vacationing in Arkansas, just in case.


Also I would highly recommend against even considering this option for many reasons.

Please elaborate.



There are plenty of go-karts out there with one-wheel drive (and brake). A different application, for sure, but many of them are pretty fast and used on pavement.

I just grabbed this from a go-kart site:

Differentials
A more complicated solution to this problem is to use a differential on the rear axle, just like a car has. This allows both wheels to be powered, and allows for easy cornering. However, it's not the best solution for serious off roading. This is because when traction is lost on one wheel, it will spin and the other won't turn at all, effectively giving you a single-wheel drive. These systems are readily available for less than $100.

Single Wheel Drive (Fixed Axle)
If you plan to use the kart for serious off roading, then a live axle is the way to go. But for hard-pack and asphalt, you can't beat a single wheel drive for the price.

A single wheel drive runs a chain from the engine clutch straight to the drive wheel, which has a sprocket mounted directly to it. The other rear wheel is left to spin free-wheel.

A single wheel drive is by far the easier and cheaper than a differential, and give you the needed slip for on-road and hard pack dirt driving.

https://www.diygokarts.com/kart-parts/go-kart-drive-axle.html

Of course, it'll be about useless on anything but pavement and hard-pack, and there wouldn't be an option to switch during a ride, without some custom locking hub. I haven't done it, but I've thought about it quite a bit, even trying one way bearings, to either have two drive tires, or two braking tires if that was a workable compromise. I don't think the one way bearings would function like intended during a turn though. I could guess at it all day, but until trying it, I wouldn't know for certain. Best I can tell, nobody has tried it. I done it to my mini trike, but that has a top speed of about 25mph and is scary enough, mainly because of the crazy steering angle, but also because the mass of the rider is behind the rear axle.

Of course, trying to do wheelies could be very complicated.

I don't know what this guy has going on, but something is fishy with that rear axle. https://www.youtube.com/watch?v=vLdzmWcKjJ0

[El Camexican]

I don't know what this guy has going on, but something is fishy with that rear axle. https://www.youtube.com/watch?v=vLdzmWcKjJ0

"This guy" was the infamous Doug Domokos, Wheelie King of my childhood. That trike was custom built to do what it did as were his bikes. https://www.youtube.com/watch?v=mqL-UPeVLc4

[ATC King]

You're saying Honda built a skid-steer ATC185, but didn't sell it to the public?:lol:
Seriously, for the people who want to add snow tracks to their trikes...


"This guy" was tongue-in-cheek. I knew who he was, and about how some of the bikes were built by his sponsors. What I didn't know exactly was how that ATC was built. If one rear brake is good, surely four are better. Thanks for the video.

BTW, it has a differential. :naughty:

[kawzilla]

Here in Il.,They are outlawed unless on private land.
I enjoy mine ice fishing on frozen lakes,which I am allowed.
Hope this helps-

[Dirtcrasher]

Wait, what!!??

In Illinois you cannot ride a 3 wheeler on or off road, only on frozen lakes you're saying??