1,500 lb eTrike???

[amberwolf]

Others have suggested looking at more robust wheels such as those for a pedicab or even scooter or motorcycle wheels. If I can make it work, I do like the classic look of a spoked/laced wheel, but if the engineering doesn’t support it, I’ll have to look at other options.

Pedicab wheels are still standard spoked/laced wheels (all the ones I've seen so far, anyway). But as Chalo points out (and I did as well earlier), they mount to a live-axle, meaning the axle runs all the way from one wheel to the other, and the axle itself spins, and it goes either thru the cargo area or under it.

You *could* design it so the axle is not all the way thru, but I'm not sure what kind of engineering it would involve for that kind of weight. On my Mk II SB Cruiser plan, I was going to modify the hubs to use a carrier that fit a spindle on a stub axle mounted to the sides of the trike's cargo area frame, so I could easily pull them off for roadside replacement, and the carrier would have a sprocket on it driven by chain (or whatever) from a motor somewhere on the trike (there are various designs with varying complexity for how to get the power to the motor, because for my setup it's more important to have a clear cargo area and as low a COG as possible than it is to have a simple drivetrain, or even "efficient").

You indicated a 48V system might not work. Are 72V or 96V systems available for ebike systems? I can go with any voltage as long as I can find a battery, an appropriate (and compact enough) inverter and it still works with the etrike motors and controls.

It's not the voltage itself, it's the total power required. That's something you'll have to work out for your specific conditions, terrain, weight, speed, acceleration desired, etc. (ebikes.ca has simulators that can help with guesstimating it).

It's possible, however, that it will be easier / cheaper to get the power required with a higher voltage system just because power (watts) is volts x amps, and a lower voltage takes more current to do the same thing.

But...the relationships between all the various parts of the system are fairly complex, so experimenting with the simulator may give you a better idea of how it works, and make it easier to choose.

I realize my etrike concept might be pushing the bounds of practicalness, but I want to verify if it’s doable before I consider switching gears to looking at vehicle types. There’s something about the coolness factor with vending bikes.

As long as the coolness is more important than other factors, there's nothing wrong with a cool machine to do a job. If something else becomes more important you can change things as much as necessary to do the job.


As for practicality, you can do a lot with bicycle parts, but there are limits to them. If you are never going very fast (walking speeds), and you don't have up or downhills to deal with, you may get away with lesser parts (brakes, motor, etc) than otherwise, for instance.

The SB Cruiser heavy-cargo-hauler trike can haul quite a bit, including itself, but your load would probably be past it's safe limits even split between it and the Mk IV trailer. Even just the piano hauling kept my max down to about half the speed I would normally go, and less when quick braking would be more of a concern; the front single mechanical disc brake can only take so much, and the same for the regen braking in the motors--enough braking in too short a time and they overheat and can fail.

Same for acceleration--if I have to accelerate quickly, it takes more power than doing it gradually, and it heats up both the motor and controller.

 

[amberwolf]

You might look at the Truck Trike design for a delta that could probably be scaled up to do this job.****

Truck Trike

0 0 1 24 137 University of Oregon 1 1 160 14.0 Normal 0 false false false EN-US JA X-NONE

web.archive.org

You can then adapt the cargo frame design to your front-loader type instead, if you want to stay with the pivot-whole-cargo-area design. Otherwise, you're probably going to have to figure out some form of steering that just moves the wheels, not the cargo box, and keep that whole area fixed as one frame with the rest of the trike.

There's two "easy" ways to do it I can think of, both of which sacrifice either space inside/under the cargo area or widen the trike by some amount; both would be controlled via some form of remote steering pushrod or cable or chain linkage:

--simplest is to have a load-bearing pivot that comes down from the "center" of the cargo area that supports a frame that does the same job as the Christiana one for securing the steering, and possibly other bearing pathways around the outer circumference of this frame. This has the thru-axle all the way across the frame, and the wheels would swing forward on the outboard side of a turn and backward on the inboard, which will shift the load around and probably require sturdier engineering.

--more complex is to use kingpin-type steering; this gives independent stub axles for each wheel, and the pivots are at the outer edges of the cargo area, while the cargo area itself is fully supported the same way by the wheels all the time.

Both of them *could* be designed with double-ended-axle wheels, but given the weight of the trike you'd probably need to put removable outboard frames on them to allow for wheel servicing without jacking it up more than half the wheel height to get the wheels out from under the frame and back in. (which is a plan I'd had at one time for the SB Cruiser as it presently exists--so far I just roll the trike over on it's side for wheel servicing.


****The SB Cruiser could probably haul 600lbs directly on the trike, not counting me and it's own weight, but I don't know how many times it could do it before something failed. :lol: The Trucktrike as it's designed could probably do some significant amount more than that 600lbs but probably not regularly or under poor conditions.

 

[Mossha150]

Pedicab wheels have much better strength-to-weight ratio than motorcycle wheels. On the other hand, pedicab wheels (the ones that would tolerate 600# each anyway) are committed to axles that rotate on their own bearings. That limits the layout of a cart or cargo trike that uses them.

Motorcycle wheels are heavy and crude by comparison, but there are lots of options that will carry the weight reliably. Also you would be able to mount an independent wheel on each side and have a low cargo floor in between. You can get MC wheels that incorporate drive sprockets, drum brakes, and other features that would be useful for your contraption. So in this case, MC wheels might give you more design space.

The e-pedicabs we use in Austin mostly have Cyclone 2-4kW shafted gearmotors running at 52V nominal with 13/30 reduction gears. A few use 6kW Cyclone motors, or reductions as low as 13/44.

Thanks for clarifying how pedicab wheels compare to motorcycle wheels. I’ll explore both ideas. Regarding pedicabs, am I correct in understanding that you and amberwolf are saying that the front wheels share a common (live) axle. If so, does that mean it incorporates a differential. And if you setup a motor drive system, you would only use a single motor, verses one motor for each of the two front wheels?

 

[Mossha150]

I planned to build a similar rickshaw carriage for the wife and our two children. She made some valid points about the children and her will suffer the most. My response was, "Operation Human Shield" .



View attachment 346722

Very cool!

 

[PaPaSteve]

Front wheels for the Worksman trike I owned had bearings in the hub which spun on a dead axle.
No front brakes.
One speed with coaster brake in the rear.

Worksman Front Loader - Model STPT

cargo bike, front load trike tadpole, ice cream trike, vending cycle, adult trike,

www.worksmancycles.com

Wheels for Horseless Carriage & Car Replicas

Wheels for Horseless Carriage & Car Replicas - The Worksman Cycles Factory Direct Store, America's Oldest Cycle Manufacturer, Industrial Bicycles and Tricycles, since 1898

www.worksmancycles.com

Pedicab we owned had one drive wheel on the rear axle and the other rear wheel coasted on bearings.
Picture shown was when it was used for cargo with passenger seating removed.



There are several different approaches to driving both rear wheels if that's the design approach you decide to choose.
A differential from a riding lawnmower is common.
There are a couple diffs designed for human powered use as well.
Here's a version using 2 single speed bicycle freewheels.

 

[PaPaSteve]

Pedicab Manufacturers

Pedal-powered taxis, also known as pedicabs, generally are manufactured in several configurations. The first type to mention is tri-cycled passenger carrying vehicles. Some of these pedicabs are created with a place for passengers in front of the cyclist, and some have the passengers behind...

pedicabs.us

 

[amberwolf]

Regarding pedicabs, am I correct in understanding that you and amberwolf are saying that the front wheels share a common (live) axle. If so, does that mean it incorporates a differential.

Pedicabs are usually delta trikes, with a non-driven front wheel.

But the rear wheels, which are driven by pedals and sometimes a motor assist, are usually a live axle. There may or may not be a diff.

However, it doesn't matter how a pedicab uses the wheels; if you look at my posts there are multiple ways you can use them dependign on how you wish to design your tadpole trike.

And if you setup a motor drive system, you would only use a single motor, verses one motor for each of the two front wheels?

Depends on your specific trike design--see my previous posts.

 

[Chalo]

Regarding pedicabs, am I correct in understanding that you and amberwolf are saying that the front wheels share a common (live) axle. If so, does that mean it incorporates a differential.

Yes, typically a Peerless diff with 1" diameter half axles.

And if you setup a motor drive system, you would only use a single motor, verses one motor for each of the two front wheels?

Yes, we use one Cyclone gearmotor with a 13t freewheel on the shaft to drive a (usually) 30t sprocket on the differential housing.

 

[PaPaSteve]

These are nice differentials and they offer interesting wheels and axles

SAMAGAGA

I have a new Peerless like this one that's been sitting for too long ... $50 plus shipping

Peerless 100-224 Differential 1" Axle | Peerless | Brands | www.surpluscenter.com

Peerless 100-224 Differential 1 Axle, Peerless, DIFFERENTIAL Brand new. PEERLESS 100-224 differential. Can be used with PEERLESS 700 seriesPeerless,100-224,

www.surpluscenter.com

 

[Mossha150]

Front wheels for the Worksman trike I owned had bearings in the hub which spun on a dead axle.
No front brakes.
One speed with coaster brake in the rear.

Worksman Front Loader - Model STPT

cargo bike, front load trike tadpole, ice cream trike, vending cycle, adult trike,

www.worksmancycles.com

Wheels for Horseless Carriage & Car Replicas

Wheels for Horseless Carriage & Car Replicas - The Worksman Cycles Factory Direct Store, America's Oldest Cycle Manufacturer, Industrial Bicycles and Tricycles, since 1898

www.worksmancycles.com

Pedicab we owned had one drive wheel on the rear axle and the other rear wheel coasted on bearings.
Picture shown was when it was used for cargo with passenger seating removed.

View attachment 346835

There are several different approaches to driving both rear wheels if that's the design approach you decide to choose.
A differential from a riding lawnmower is common.
There are a couple diffs designed for human powered use as well.
Here's a version using 2 single speed bicycle freewheels.

View attachment 346837

Thanks for sharing your thoughts and examples. I would never have thought about using a differential from a riding lawn mower. Good to know there are options.

 

[Mossha150]

You might look at the Truck Trike design for a delta that could probably be scaled up to do this job.****

Truck Trike

0 0 1 24 137 University of Oregon 1 1 160 14.0 Normal 0 false false false EN-US JA X-NONE

web.archive.org

You can then adapt the cargo frame design to your front-loader type instead, if you want to stay with the pivot-whole-cargo-area design. Otherwise, you're probably going to have to figure out some form of steering that just moves the wheels, not the cargo box, and keep that whole area fixed as one frame with the rest of the trike.

There's two "easy" ways to do it I can think of, both of which sacrifice either space inside/under the cargo area or widen the trike by some amount; both would be controlled via some form of remote steering pushrod or cable or chain linkage:

--simplest is to have a load-bearing pivot that comes down from the "center" of the cargo area that supports a frame that does the same job as the Christiana one for securing the steering, and possibly other bearing pathways around the outer circumference of this frame. This has the thru-axle all the way across the frame, and the wheels would swing forward on the outboard side of a turn and backward on the inboard, which will shift the load around and probably require sturdier engineering.

--more complex is to use kingpin-type steering; this gives independent stub axles for each wheel, and the pivots are at the outer edges of the cargo area, while the cargo area itself is fully supported the same way by the wheels all the time.

Both of them *could* be designed with double-ended-axle wheels, but given the weight of the trike you'd probably need to put removable outboard frames on them to allow for wheel servicing without jacking it up more than half the wheel height to get the wheels out from under the frame and back in. (which is a plan I'd had at one time for the SB Cruiser as it presently exists--so far I just roll the trike over on it's side for wheel servicing.


****The SB Cruiser could probably haul 600lbs directly on the trike, not counting me and it's own weight, but I don't know how many times it could do it before something failed. :lol: The Trucktrike as it's designed could probably do some significant amount more than that 600lbs but probably not regularly or under poor conditions.

I did stumble across the truck trike. It’s an interesting and robust design. Thanks for the thoughts on the steering configurations. I was leaning towards putting the pivot on the rear face of the cargo area, so the front wheels would be fixed and turn with the cargo area. I thought this would be the simplest and preserve the most of the donor bike by cutting the head tube off and fabricating a custom pivoting setup. Your thoughts on an outboard frame to try to avoid jacking Is well taken.

 

[PaPaSteve]

Steering dynamics does involve physics.
Speed, weights, length of levers are part of the equations.
The distance from the tire(s) contact patch to the steering pivot does matter.
Looking at the front fork of a typical bicycle or motorcycle the distance from the contact patch to the steering pivot is a couple inches whereas the handlebars might be 24" wide giving the rider some 10 times more mechanical advantage over the relatively light weight steering input from the forward motion of the bike.
With the Worksman trike the distance from the tire contact patch to the steering pivot is much longer then the riders handlebar so the weight of the load has more say in where the trike is heading. (and your proposed load is quite high)
Also not ideal or typical of most vehicles is the tire(s) contact patch is well forward of the steering pivot.
Not saying you can't make a front loader work in your application, just be prepared for some unexpected and hard to control steering motions.

 

[amberwolf]

. I was leaning towards putting the pivot on the rear face of the cargo area, so the front wheels would be fixed and turn with the cargo area. I thought this would be the simplest and preserve the most of the donor bike by cutting the head tube off and fabricating a custom pivoting setup. Your thoughts on an outboard frame to try to avoid jacking Is well taken.

I think you're going to find that kind of mass very difficult to steer even at very low speeds on flat paved surfaces. It will take quite a bit of force to start a turn, and the same force to stop the turn.

With very simple-to-build direct steering (like the Christiana trikes have) you'll need very wide bars to get a lot of leverage, and that makes it harder to reach them as the turn progresses; the outboard side will move quite far forward, and the inboard side quite far back.

You could design a linkage or remote steering that gives you a mechanical advantage; a kind of "power steering", and use more normal width bars, but this has the disadvantage that it is more complex and easier to break.


Have you ever moved and steered >1/2 ton pallets with a manual unpowered pallet jack? If not, you might try it out in a warehouse somewhere near you to get an idea of the problems involved. It's a different scenario than the trike would be, and because of where the wheel and it's pivot is on the jack, is actually probably easier to steer than the trike with it's pivot at the back of the cargo area.

In my experience it's easier to pull a large mass thru a turn, steered by a more typical front end, than it is to push it thru the turn. It's also easier to see where you're going, etc., without it in the way. Steering is MUCH simpler to design and build for a delta than a tadpole, especially for huge heavy things like this.

 

[Mossha150]

Yes, typically a Peerless diff with 1" diameter half axles.



Yes, we use one Cyclone gearmotor with a 13t freewheel on the shaft to drive a (usually) 30t sprocket on the differential housing.

Thanks for confirming. For my understanding, if you use a single speed BLDC motor with a differential for the front wheels, would I still keep the stock rear wheel drive train with a 7-speed cassette? And what do you use to control the front motor? Does it interface with any sort of pedal torque sensor or simply a throttle? I’m still looking at pedicab and motorcycle wheels to get some ideas. Do you know anything about Thicc pedicab rims and wheels, by Precision Pedicab Manufacturing? They claim to be some of the best.

 

[Chalo]

Thanks for confirming. For my understanding, if you use a single speed BLDC motor with a differential for the front wheels, would I still keep the stock rear wheel drive train with a 7-speed cassette?

Sure, no reason to change that.

And what do you use to control the front motor? Does it interface with any sort of pedal torque sensor or simply a throttle?

Throttle only, almost always. Early on we installed a torque sensor, but it failed rapidly in the rough and tumble.

I’m still looking at pedicab and motorcycle wheels to get some ideas. Do you know anything about Thicc pedicab rims and wheels, by Precision Pedicab Manufacturing? They claim to be some of the best.

I put my friend up to getting those rims manufactured in 48 hole after I built a pair of pedicab wheels with the then-available 36 hole version. He also had hubs made wider than industry standard to offset the larger diameter of 29er wheels which we also pioneered for pedicabs.

That enterprise inspired another one of my friends here in town to go even bigger and have custom rim extrusions made. His rims are the same width as Precision Thicc, but at least 75% heavier so they should be stronger yet.

Rear Wheel for Pedicabs and E-bikes - Unbroken Components

This is our heavy duty rear 26" pedicab wheel for a 1" axle. This pedicab wheel has been designed from the ground up to easily withstand the forces that an electric pedicab experiences. This pedicab wheel is 65mm wide to support wider tires (2.5" to 4") to better help cushion the impact of...

unbrokencomponents.com

 

[amberwolf]

Early on we installed a torque sensor, but it failed rapidly in the rough and tumble.

Presuming that was a BB TS, I wonder if any of these would fare better?

Rear all axle v3 with torque sensor

https://ebikes.ca/product-info/grin-products/all-axle-hub-motor.html Came out in the Christmas newsletter. Super stoked to see the torque sending quality

endless-sphere.com

 

[Chalo]

Presuming that was a BB TS, I wonder if any of these would fare better?

Rear all axle v3 with torque sensor

https://ebikes.ca/product-info/grin-products/all-axle-hub-motor.html Came out in the Christmas newsletter. Super stoked to see the torque sending quality

endless-sphere.com

Maybe? But we don't use hub motors on pedicabs generally. They're seen (and used) as an expedient and disposable option for cheapskates. (Mostly because these nincompoops refuse to match battery voltage with motor RPM/volt, or even understand why they should do so.)

Cyclone 2-4kW gearmotors present a hard to beat combination of low cost, robustness, repairability, power, and retail support that has so far prevented other solutions from rivaling them.

 

[Mossha150]

Steering dynamics does involve physics.
Speed, weights, length of levers are part of the equations.
The distance from the tire(s) contact patch to the steering pivot does matter.
Looking at the front fork of a typical bicycle or motorcycle the distance from the contact patch to the steering pivot is a couple inches whereas the handlebars might be 24" wide giving the rider some 10 times more mechanical advantage over the relatively light weight steering input from the forward motion of the bike.
With the Worksman trike the distance from the tire contact patch to the steering pivot is much longer then the riders handlebar so the weight of the load has more say in where the trike is heading. (and your proposed load is quite high)
Also not ideal or typical of most vehicles is the tire(s) contact patch is well forward of the steering pivot.
Not saying you can't make a front loader work in your application, just be prepared for some unexpected and hard to control steering motions.

I appreciate your thoughts on steering challenges I can expect to have. Something else definitely I need to consider.

 

[Mossha150]

I think you're going to find that kind of mass very difficult to steer even at very low speeds on flat paved surfaces. It will take quite a bit of force to start a turn, and the same force to stop the turn.

With very simple-to-build direct steering (like the Christiana trikes have) you'll need very wide bars to get a lot of leverage, and that makes it harder to reach them as the turn progresses; the outboard side will move quite far forward, and the inboard side quite far back.

You could design a linkage or remote steering that gives you a mechanical advantage; a kind of "power steering", and use more normal width bars, but this has the disadvantage that it is more complex and easier to break.


Have you ever moved and steered >1/2 ton pallets with a manual unpowered pallet jack? If not, you might try it out in a warehouse somewhere near you to get an idea of the problems involved. It's a different scenario than the trike would be, and because of where the wheel and it's pivot is on the jack, is actually probably easier to steer than the trike with it's pivot at the back of the cargo area.

In my experience it's easier to pull a large mass thru a turn, steered by a more typical front end, than it is to push it thru the turn. It's also easier to see where you're going, etc., without it in the way. Steering is MUCH simpler to design and build for a delta than a tadpole, especially for huge heavy things like this.

Sounds like I have some things to figure out for steering or start hitting the gym!

 

[Mossha150]

Sure, no reason to change that.



Throttle only, almost always. Early on we installed a torque sensor, but it failed rapidly in the rough and tumble.



I put my friend up to getting those rims manufactured in 48 hole after I built a pair of pedicab wheels with the then-available 36 hole version. He also had hubs made wider than industry standard to offset the larger diameter of 29er wheels which we also pioneered for pedicabs.

That enterprise inspired another one of my friends here in town to go even bigger and have custom rim extrusions made. His rims are the same width as Precision Thicc, but at least 75% heavier so they should be stronger yet.

Rear Wheel for Pedicabs and E-bikes - Unbroken Components

This is our heavy duty rear 26" pedicab wheel for a 1" axle. This pedicab wheel has been designed from the ground up to easily withstand the forces that an electric pedicab experiences. This pedicab wheel is 65mm wide to support wider tires (2.5" to 4") to better help cushion the impact of...

unbrokencomponents.com

Thanks for clarifying. Okay, so if I use Unbroken Components’ wheels, would you use their front or their rear wheel version for the two front wheels on a tadpole trike? If I use a Peerless differential/axle type setup, should I attempt to support the outside of the wheel hubs as well? Or can they be supported from only one side? I did see the Peerless 1” axle is rated for 600 lbs. Assuming my front end (where the bulk of my weight will be) will be more than 600 lbs, should I look for a larger diameter axle setup and turn down the ends to 1” for the pedicab hubs? I‘m curious if I should look into heavier-duty axles/differentials? Would golf cart or UTV axles be worth considering? Others have mentioned steering will likely be a challenge with my tadpole setup. Do you find that to be the case with pedicabs with the passengers in the front? Are there steering systems using linkages or hydraulics to assist with the weight?

 

[Mossha150]

Maybe? But we don't use hub motors on pedicabs generally. They're seen (and used) as an expedient and disposable option for cheapskates. (Mostly because these nincompoops refuse to match battery voltage with motor RPM/volt, or even understand why they should do so.)

Cyclone 2-4kW gearmotors present a hard to beat combination of low cost, robustness, repairability, power, and retail support that has so far prevented other solutions from rivaling them.

With a heavier than usual trike, would you consider using Cyclone’s 6kW gearmotor? What is the advantage of a gearmotor over a non-geared motor? Also, how do you determine what size kW motor you need for a given application?

 

[RunForTheHills]

This looks like a similar idea, but mounted on a golf cart.
Florida Keg Karts

 

[amberwolf]

Maybe? But we don't use hub motors on pedicabs generally. They're seen (and used) as an expedient and disposable option for cheapskates. (Mostly because these nincompoops refuse to match battery voltage with motor RPM/volt, or even understand why they should do so.)

Ah, sorry for the confusion: I wasn't pointing to the motors being discussed in the thread, but to the freewheel / cassette based sensors (which could be mounted to custom-built wheel hubs or to a jackshaft in the pedal driveline, etc).

 

[amberwolf]

Also, how do you determine what size kW motor you need for a given application?

As previously posted

1,500 lb eTrike???

Others have suggested looking at more robust wheels such as those for a pedicab or even scooter or motorcycle wheels. If I can make it work, I do like the classic look of a spoked/laced wheel, but if the engineering doesn’t support it, I’ll have to look at other options. Pedicab wheels are...

endless-sphere.com

one good way is to take your riding conditions, etc. to calculators or simulators like those on ebikes.ca , to guesstimate your probable power usage under various conditions with various drivetrains / gear ratios / wheel sizes / etc, as well as wh/mile to guesstimate battery capacity required for your range needs.

 

[Chalo]

Ah, sorry for the confusion: I wasn't pointing to the motors being discussed in the thread, but to the freewheel / cassette based sensors (which could be mounted to custom-built wheel hubs or to a jackshaft in the pedal driveline, etc).

I see. I assumed those sensors were dedicated to hub motors, because their interfaces aren't like anything I've seen on bicycle hubs.

Many pedicabs use ordinary rear disc brake hubs as a jackshaft for the pedal drive. Pedals engage a normal cassette on the right, and a sprocket attached to the disc brake pattern carries the drive chain to the rear differential. But more commonly, it's a pedicab specific part that has a 7 speed freewheel on the right and a fixed cog on the left. So if a dummy hub were used that could hold one of the torque sensing freehubs , that would allow easy application to a pedicab.

Between the sensor and a powerful controller that can interpret a torque sensor (or a CA), I think the system would be both too complicated and too expensive for most pedicabbers' liking. They are a primitive species.