I want to build this

[Oldbikeguy]

I want to build this (see below)
I want it to be completely EV no pedals. I am a competent woodworker and can have a metal frame fabricted but am new to EV. Max speed would be 20 miles an hour. I am thinking an electric differential would be the best but would like suggestions. Thank you in advance.

 

[amberwolf]

You might peek over here for a similar build, it may give you some ideas:

C Cab Hot Rod Power Advice

Ed here. I've been aware of this site for a number of years, and have looked in, now and then. But now I'm getting to the point in my build that I need, the kind of help this site seems to be able to provide. I'm currently building a C Cab Hot Rod, and I'm seeking advice on what power will be...

endless-sphere.com

 

[marty]

I would search the world for a ready built electric tricycle then modify as needed. Build body in you picture from wood, plastic, or metal.

 

[Oldbikeguy]

You might peek over here for a similar build, it may give you some ideas:

C Cab Hot Rod Power Advice

Ed here. I've been aware of this site for a number of years, and have looked in, now and then. But now I'm getting to the point in my build that I need, the kind of help this site seems to be able to provide. I'm currently building a C Cab Hot Rod, and I'm seeking advice on what power will be...

endless-sphere.com

Thank you that was super helpful, I and specifically wondering about a electric motor Differential. Would you have any experience with those?

 

[Oldbikeguy]

I would search the world for a ready built electric tricycle then modify as needed. Build body in you picture from wood, plastic, or metal.

Thank you I have thought of that but there are some problems. First the ones I have looked at have pedals which I don't want, secondly the frame would have to be extensively modified and lastly I worry that the system would not be able to handle the additional weight.

 

[amberwolf]

I haven't used any of the differentials with built in motors, if that's what you're referring to, but they are commonly used on some pedicabs, which would be a similar (but heavier) usage to this one, though usually at a lower speed.

I don't know what speeds the various diffs are geared for vs their motor votlage, but if you find one that is close to the speed you want, but nto quite there, you could probably run it at a higher voltage to get the higher speed.

If you use a diff that is separate from the motor (also common enough in pedicabs), you can then change the sprocket gearing ratio between motor output and diff input, to change the speed at the wheels (though increasing the speed this way reduces the torque, where that isn't the case with increasing the voltage to the motor, if that matters to the application).

What kind of terrain and riding conditions will you have to deal with? If it's all flat terrain, you can get away with less motor and "taller" gearing. If you have hills, you may need lower gearing and/or a bigger motor (and heftier controller and battery) to provide the power needed for those. The heavier the vehicle plus driver/passengers/cargo, the more power it will need for anything other than flat roads (or for faster acceleration).

What kind of acceleration do you need under the various riding conditions? Faster acceleration requires higher torque, so a bigger motor/etc or lower gearing (or both), just like hills, for the same reasons.

How much range do you need at what speed under which conditions? This determines how much battery you need (vs how capable the battery has to be at supplying power).

 

[Oldbikeguy]

You might peek over here for a similar build, it may give you some ideas:

C Cab Hot Rod Power Advice

Ed here. I've been aware of this site for a number of years, and have looked in, now and then. But now I'm getting to the point in my build that I need, the kind of help this site seems to be able to provide. I'm currently building a C Cab Hot Rod, and I'm seeking advice on what power will be...

endless-sphere.com

Thank you that is really interesting

 

[Oldbikeguy]

I haven't used any of the differentials with built in motors, if that's what you're referring to, but they are commonly used on some pedicabs, which would be a similar (but heavier) usage to this one, though usually at a lower speed.

I don't know what speeds the various diffs are geared for vs their motor votlage, but if you find one that is close to the speed you want, but nto quite there, you could probably run it at a higher voltage to get the higher speed.

If you use a diff that is separate from the motor (also common enough in pedicabs), you can then change the sprocket gearing ratio between motor output and diff input, to change the speed at the wheels (though increasing the speed this way reduces the torque, where that isn't the case with increasing the voltage to the motor, if that matters to the application).

What kind of terrain and riding conditions will you have to deal with? If it's all flat terrain, you can get away with less motor and "taller" gearing. If you have hills, you may need lower gearing and/or a bigger motor (and heftier controller and battery) to provide the power needed for those. The heavier the vehicle plus driver/passengers/cargo, the more power it will need for anything other than flat roads (or for faster acceleration).

What kind of acceleration do you need under the various riding conditions? Faster acceleration requires higher torque, so a bigger motor/etc or lower gearing (or both), just like hills, for the same reasons.

How much range do you need at what speed under which conditions? This determines how much battery you need (vs how capable the battery has to be at supplying power).

That is super helpful. There are no grades I will be using it to tool around town in flat Detroit area. I do not plan to go fast at all. Basically it is like a mobility cart that looks cool and has storage. I have even wondered if a 1000w front hub motor would work. I weigh 219 and the box I will build Have calculated to be about 400lbs. Thanks again

 

[amberwolf]

A hubmotor can work....depends on how much acceleration you want, and how fast you want to go.

Example:

My SB Cruiser trike

The SB Cruiser : Amberwolf's 2WD Heavy Cargo Trike & Dog Carrier

This thing replaces Delta Tipper...er, Tripper v1.0, whcih was cannibalized to build it. https://endless-sphere.com/forums/viewtopic.php?f=2&t=22720 It's mostly Dogman's fault ;) ...er, inspiration, as he suggested it as a joint build for his trip out here this year. Tiny and Yogi discuss...

endless-sphere.com

is pretty heavy (probably weighs what you expect yours plus you to when I'm carrying enough groceries, dog food, or a dog), and it takes 3-4kw to accelerate it to 20mph on the flat Phoenix roads in about 4-5 seconds when it's just me on it (total 400-500lbs?), probably a second or two longer with the extra weight; I'm using two hubmotors in what amount to 22" or so wheels, each with it's own controller, but both run at the same time with the throttle signal out of the Cycle Analyst that reads my pedal sensor so I can just pedal to control the speed directly. (it also has a throttle but that's only used to get started if hurts too much to start by pedalling, or I can't pedal at all for whatever reason).

In an earlier lighter version, probably a hundred pounds less, I used a single front hubmotor in a 26" wheel with probably 1500w of power max; acceleration wasn't as good, though I could still do 20MPH. (probably could've done faster but don't need more, and trikes like these don't usually handle that well at higher speeds (many are terrible even at 15MPH). This single motor was pushed hard enough to heat it up a lot, but it was an old heavy duty motor...I did eventually break it's axle, though (after I moved it to the rear into a smaller wheel).

I use hubmotors because it makes things simpler and potentially more reliable than a chain drive from a frame-mounted motor to the wheel (which I have done before, on the early versions of CrazyBike2). But for other reasons, primarily roadside tire repair time/work, a future version of the trike is going to use regular wheels driven via chain from frame mounted motors, once I decide on a specific design and have time to build it).


If you don't need much speed, you can get "slower wind" hubmotors intended for trikes, like these

Traditional Tricycle Conversion System

Special parts for converting a Traditional upright Tricycle to Electric. Simple and durable front w/ 48 volt Lithium battery from a USA company: the best val...

www.ebikekit.com

which will spin slower but give more torque than a typical hubmotor in the same size wheel at the same voltage.

Or you can use small diameter wheels for the typical hubmotors, which do a similar thing in a different way.

Or even do both, trike-kit motor in small wheel, for even lower speed but higher torque.

Geared hubmotors like the Gmac from ebikes.ca may be even more efficient at the lower speed / startup from a stop. (suggesting the Gmac specifically because it can spin both directions, unlike typical geared hubmotors, so you can use it to back up as well as go forward, like the DD hubmotors in those trike kits).

 

[Chalo]

Consider starting with a secondhand pedicab trike, removing the passenger carriage and replacing with whatever body you like. You can install footpegs in the bottom bracket shell instead of cranks.

Main Street Pedicabs "Classic" model is probably the most plentiful, least in-demand model in the USA right now, because the industry is adapting to the availability of electric assist by transitioning to larger pedicab trikes. The Classic trike is set up for two passengers, which makes it small by pedicab standards but nearly ideal for what you are planning.

Here in Austin, most pedicabs use the 2-4kW Cyclone gearmotor driving the rear differential by a chain reduction, but it is easier to install a front hub motor (and more reliable).

There are cheap Chinese clones of both Main Street Classic and Cycles Maximus trikes that might be less expensive if you can find one, but equally suitable as a base for your project.

 

[Oldbikeguy]

Consider starting with a secondhand pedicab trike, removing the passenger carriage and replacing with whatever body you like. You can install footpegs in the bottom bracket shell instead of cranks.

Main Street Pedicabs "Classic" model is probably the most plentiful, least in-demand model in the USA right now, because the industry is adapting to the availability of electric assist by transitioning to larger pedicab trikes. The Classic trike is set up for two passengers, which makes it small by pedicab standards but nearly ideal for what you are planning.

Here in Austin, most pedicabs use the 2-4kW Cyclone gearmotor driving the rear differential by a chain reduction, but it is easier to install a front hub motor (and more reliable).

There are cheap Chinese clones of both Main Street Classic and Cycles Maximus trikes that might be less expensive if you can find one, but equally suitable as a base for your project.

Wow Thank you That is super helpful.

 

[Oldbikeguy]

A hubmotor can work....depends on how much acceleration you want, and how fast you want to go.

Example:

My SB Cruiser trike

The SB Cruiser : Amberwolf's 2WD Heavy Cargo Trike & Dog Carrier

This thing replaces Delta Tipper...er, Tripper v1.0, whcih was cannibalized to build it. https://endless-sphere.com/forums/viewtopic.php?f=2&t=22720 It's mostly Dogman's fault ;) ...er, inspiration, as he suggested it as a joint build for his trip out here this year. Tiny and Yogi discuss...

endless-sphere.com

View attachment 331803
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is pretty heavy (probably weighs what you expect yours plus you to when I'm carrying enough groceries, dog food, or a dog), and it takes 3-4kw to accelerate it to 20mph on the flat Phoenix roads in about 4-5 seconds when it's just me on it (total 400-500lbs?), probably a second or two longer with the extra weight; I'm using two hubmotors in what amount to 22" or so wheels, each with it's own controller, but both run at the same time with the throttle signal out of the Cycle Analyst that reads my pedal sensor so I can just pedal to control the speed directly. (it also has a throttle but that's only used to get started if hurts too much to start by pedalling, or I can't pedal at all for whatever reason).

In an earlier lighter version, probably a hundred pounds less, I used a single front hubmotor in a 26" wheel with probably 1500w of power max; acceleration wasn't as good, though I could still do 20MPH. (probably could've done faster but don't need more, and trikes like these don't usually handle that well at higher speeds (many are terrible even at 15MPH). This single motor was pushed hard enough to heat it up a lot, but it was an old heavy duty motor...I did eventually break it's axle, though (after I moved it to the rear into a smaller wheel).

I use hubmotors because it makes things simpler and potentially more reliable than a chain drive from a frame-mounted motor to the wheel (which I have done before, on the early versions of CrazyBike2). But for other reasons, primarily roadside tire repair time/work, a future version of the trike is going to use regular wheels driven via chain from frame mounted motors, once I decide on a specific design and have time to build it).


If you don't need much speed, you can get "slower wind" hubmotors intended for trikes, like these

Traditional Tricycle Conversion System

Special parts for converting a Traditional upright Tricycle to Electric. Simple and durable front w/ 48 volt Lithium battery from a USA company: the best val...

www.ebikekit.com

which will spin slower but give more torque than a typical hubmotor in the same size wheel at the same voltage.

Or you can use small diameter wheels for the typical hubmotors, which do a similar thing in a different way.

Or even do both, trike-kit motor in small wheel, for even lower speed but higher torque.

Geared hubmotors like the Gmac from ebikes.ca may be even more efficient at the lower speed / startup from a stop. (suggesting the Gmac specifically because it can spin both directions, unlike typical geared hubmotors, so you can use it to back up as well as go forward, like the DD hubmotors in those trike kits).

Thank you so much for taking the time to share that. It is incredibly helpful and very much like what I am building.

 

[Oldbikeguy]

I building a little van mobility cart. I had considered using a front hub motor and still might go that route, but was wondering if I could take a trike differential and mount a motor mid frame or on purchase a differential with a motor. The reason I am considering a differentiaI is it would allow for brake mounting and avoid tire scrubbing. I would love to hear your experience and recommendations.

Ps It looks like Dogman who built a similar vehicle is no longer on the forum.

 

[amberwolf]

I don't remember dogman building a trike, but I haven't done a search yet, and my brain doesn't work like it used to. Could you link the thread?

He did help me start building the front end of my SB Cruiser trike that was then mated to the "trike kit" (an ancient Schwinn one meant for a bike with an IGH rear wheel) I'd used to build Delta Tripper with (DT was scrapped to build SBC).

As I think Chalo has noted in your other thread (don't recall if he went into specifics about the drivetrain), some pedicabs use this design of a diff powered by motor, some use a single brake rotor mounted on the axle with caliper mounted to the frame to brake the whole diff.

I've considered a diff and was suggested various versions of the Peerless type, including some from go-carts, lawn tractors, pedicabs, golf-carts etc. The one I am most inclined to use myself is one with an input sprocket (or pulley) that sits "on top" of the diff, pointing down into it, so I could use a big hubmotor I've got here as it's input, and turn the hubmotor so it's parallel to the ground (instead of perpendicular to it), which would save space in my trike's design.

In my case, the diff would not directly drive the wheels via their hubs, because in my case the trike deck would be below the large-diameter-wheel axles, to keep the center of gravity as low as possible even when unloaded. So for mine the ends of the diff axle would be supported by pillow-block bearings and have sprockets on them, that drive sprockets on the wheels via a short chain. (this also means I could change the gearing of the motor-to-diff, to optimize the speed or torque as needed for those two parts, *and* change the gearing from diff to wheels to optimize that as well, for the trike as a whole).

For mine, the disc brakes would be on the wheels themselves, rather than the diff axle, partly because this allows me to brake each wheel independently if desired for control in certain situations (though that would require a brake lever setup that allows this as well, and I haven't built one of those yet; haven't seen one I could buy off the shelf). Mostly it's just because it would put all the braking stress on the wheels, and not on the connection between wheel and axle.


In my case I also have considered a front geared hubmotor *and* the motor-powered diff for the rear, so that I have redundancy in the drivetrain and won't get stuck somewhere just because one motor system failed. (I can still pedal the SBC, for instance, but just barely, at about 1MPH, for at most a few minutes at a time (less, probably)--BTW, you'd asked an implied question in a PM, whether the SBC was originally meant to not have pedals--no, it was always meant to have pedals, as it must have to be a "bicycle" (and for redundancy of drivetrain should all motor power / systems / etc fail).

For that option, it'd use a geared hubmotor in front because they're smaller and lighter for similar torque to a DD hub, but can freewheel (coast) when unpowered with very little drag vs a DD hub.





FWIW, disc brake mounting can be done on any wheel hubs that have rotor mounts (so you just buy or build wheels that have this type of hub), the frame just needs to allow for mounting the caliper in the right place (be built or modified to do so). You could use bicycle brakes, or moped / motorcycle brakes. (SB Cruiser uses a single Avid BB7 MTN caliper and 200mm rotor on the front wheel, and it is sufficient to make the front wheel skid; if I ever get around to rebuilding the fender frames / etc at the rear to accomodate the calipers and space for the rotors, I'll add the same brakes (probalby with 180mm rotors as I have a pair of those, but no more 200's) to the rear wheels and probably decrease my stopping distance significantly.

The small contact patch of my front 26" wheel with the CST City tire (which has great grip) is limiting my braking, not the brake itself; it brakes better with pressure around 30-35PSI but the trike rides and controls better at 45-50PSI, so I keep it up in that range.

Rim brakes are probably not what you're after, but those would be possible as well, given the right frame design and suitable rims and brake arms/etc. (I used those before the Avid, and they worked, but after I broke my fork, the one I had to build to replace it with was much easier to use disc brakes (where the caliper mount simply aligns with the dropout) than to try to build a fixture to align rim brake studs on the fork legs, etc., or try to do what I did with the previous fork with clamping on (or welding on) the entire brake arch and studs from another fork (or two). It also meant I could experiment freely with wheels and rims both width and diameter, as long as they had a disc-rotor-mount hub).

 

[Oldbikeguy]

I am planning to build this 3 wheeled vehicle. Many have suggested a front hub to power it. I have attempted to get help from local electric bike shops, but no one seems to want to step away from the typical pedal bikes. So I am hoping to get some help here. Do you think a front hub is way to go? If so is a 1000 wt unit the right choice? Besides the motor what specific parts do I need to complete the project? Where can I purchase all the parts needed?
Thank you in advance for sharing your knowledge.

 

[lnanek]

There's a lot of threads on that you could search. Most of them mention front motor trikes have a lot of traction problems. Like the wheel will spin out trying to go up hill. The weight is mostly in the back wheels.

Have you considered just electrifying one of the rear wheels? That approach is so common that Grin provides pre-built adapters for common trike brands:

Single Side Applications
Catrike electrified with two Grin All Axle MotorsA unique feature of the All-Axle hub design is its ability to work in applications requiring a single side mount. This allows the side wheels of trikes and quads to be readily electrified for the first time, and is especially popular with tadpole trikes running an internal gear hub rear wheel.

All-Axle Hub Motor - Grin Products - Product Info

The All Axle motor takes the simplicity and robustness of the direct drive hub motor, and optimizes it for the modern bike platform. This hub is fully compatible with all quick release and thru-axle bike forks, it is over 30% lighter than standard generic hubs of similar power (4kg vs 6kg), and...

ebikes.ca

 

[Oldbikeguy]

There's a lot of threads on that you could search. Most of them mention front motor trikes have a lot of traction problems. Like the wheel will spin out trying to go up hill. The weight is mostly in the back wheels.

Have you considered just electrifying one of the rear wheels? That approach is so common that Grin provides pre-built adapters for common trike brands:

All-Axle Hub Motor - Grin Products - Product Info

The All Axle motor takes the simplicity and robustness of the direct drive hub motor, and optimizes it for the modern bike platform. This hub is fully compatible with all quick release and thru-axle bike forks, it is over 30% lighter than standard generic hubs of similar power (4kg vs 6kg), and...

ebikes.ca

Thank you, I would love to hear more. I have a non powered differential and it looks like the Grin would work with that, but am not sure. Do you know?

 

[amberwolf]

I hope you don't mind, but I moved all your threads about this project into your original one to keep all the project info and discussion in one place, so you don't have some people helping you in one and some in others, each asking questions already answered in other threads they don't know about, and to help you find all the answers to make building it easier.

I am planning to build this 3 wheeled vehicle. Many have suggested a front hub to power it. I have attempted to get help from local electric bike shops, but no one seems to want to step away from the typical pedal bikes. So I am hoping to get some help here. Do you think a front hub is way to go? If so is a 1000 wt unit the right choice? Besides the motor what specific parts do I need to complete the project? Where can I purchase all the parts needed?
Thank you in advance for sharing your knowledge.

What you will need depends on exactly what you want it to do under what specific conditions. Some of that's already been discussed above (conditions, weight, speed), but not everything was answered yet (range, acceleration, etc). If you take the specifics of the job you need it to do and put them into the ebikes.ca motor and/or trip simulators, you can play with different systems to see if they will do the job, and what kind of power levels you will need to do the job under your conditions.

As a guesstimate from my own SB Cruiser usage, I'd say that 2kW+ is likely to be useful, 800-1200W is probably minimum required, 4kW+ will be much better performance on acceleration / headwinds.

If you don't need quick acceleration, and don't mind taking up to a quarter mile or half mile or more to reach 20mph, a 1000W hubmotor will probably, on completely flat terrain with no winds, maintain 20mph with something built the way your picture shows, maxing out the motor power all the time. If there's more drag than my SB Cruiser trike has, either from air resistance on the canopy/body or rolling resistance on the tires, it'll take more power than that.

If you use a middrive system (diff or no diff) motor chained or belted to a wheel or wheels, the same power will still be needed to maintain the same speed, but you can gear it for higher torque, and use a physically smaller motor (as long as the motor can still handle the power), as long as the motor can still spin fast enough . If a gear-shiftable diff or transmission is used (even a two- or three-speed bicycle drivetrain of some type), you can set it up for a low gear for acceleration and a high gear for cruising speed.

A hubmotor will be less maintenance as long as it is in a well-built wheel (the cheap kits probably won't be because they use too thick spokes for the rims they use), but you can get ones that will be from places like ebikes.ca just costs more, or you can build it yourself or have one built at a local bike shop using just a bare hubmotor and the rim you need to support the weight of your system that can survive the road conditions you'll have.

Whatever you use, you'll also need a battery that can continously output the power needed, probably at least 1000w or more, for the entire distance/time you need to ride it.

At a guess it will take 60-100Wh/mile at 20MPH to operate something built like yours, on flat roads with no wind and good road conditions. Rounding up, that means it will take at least 100Wh for every mile you want to go. If you want 30 miles of range, you need 3000Wh of battery. If it's a 52v system, that means 3000Wh / 52v = 58Ah of battery. Call it 60Ah. Etc.

You may need less power, and you may need less range capability, but you'll have to either use the simulators to guesstimate your usage/etc or experiment once you have it built, to see what actual usage and power requirements are.

 

[nicobie]

Google is your friend.

AW and Chalo nailed it.

XP Electric Trike | Lectric eBikes

Shop our XP™ Electric Trike, the industry's first foldable and fully-assembled 3-wheel electric tricycle accommodating a wide range of abilities for anyone to enjoy.

lectricebikes.com

 

[amberwolf]

I wouldn't go with one of those trikes to convert into what he wants, it would require completely disassembling it and welding all the bits to a new frame to make a C-cab style trike out of it. That's sort of what I started with on Delta Tripper that was then converted into the first version of SB Cruiser, and it is still a mechanical mess because of it.

Starting from scratch, or from a trike already built as the style pictured in the first post (and a couple of Oldbikeguy's other posts), or Ed's from the C-cab advice thread, or a pedicab frame, would be much better for this kind of build.

 

[offGridDownUnder]

I don't think you mentioned what jurisdiction you plan to ride in. You may want to research this.

I live in Australia - an electric 'bicycle' which can be drive by throttle without pedaling (with or without pedals) is an 'electric motorcycle' and must go through inspection and licensing to be ridden on any public road and may be prohibited from shared paths. You must also have insurance.

I'm certain there are people here who flout this - but if anything happens that brings them to the attention of the authorities, such as a collision with another cyclist, even if they don't cause the collision, then they have no legal defense, and the other cyclist can sue for damages.

 

[amberwolf]

I don't think you mentioned what jurisdiction you plan to ride in.

He said in this post

I want to build this

I want to build this (see below) I want it to be completely EV no pedals. I am a competent woodworker and can have a metal frame fabricted but am new to EV. Max speed would be 20 miles an hour. I am thinking an electric differential would be the best but would like suggestions. Thank you in...

endless-sphere.com

that he's in the Detroit area (which is in Michigan, USA).

 

[offGridDownUnder]

He said in this post

I want to build this

I want to build this (see below) I want it to be completely EV no pedals. I am a competent woodworker and can have a metal frame fabricted but am new to EV. Max speed would be 20 miles an hour. I am thinking an electric differential would be the best but would like suggestions. Thank you in...

endless-sphere.com

that he's in the Detroit area (which is in Michigan, USA).

I see. I'll leave the post as others read, and laws change. I won't research Detroit - I'm very unlikely to live there.

 

[From-A-To-B]

As a guesstimate from my own SB Cruiser usage, I'd say that 2kW+ is likely to be useful, 800-1200W is probably minimum required, 4kW+ will be much better performance on acceleration / headwinds.

If you don't need quick acceleration, and don't mind taking up to a quarter mile or half mile or more to reach 20mph, a 1000W hubmotor will probably, on completely flat terrain with no winds, maintain 20mph with something built the way your picture shows, maxing out the motor power all the time. If there's more drag than my SB Cruiser trike has, either from air resistance on the canopy/body or rolling resistance on the tires, it'll take more power than that.

A helpful post, as always AW.

To offer another data point: I’m rehabbing a 400 pound pedicab (driver weight included) powered by a 800W-rated DD front hub. No problem with traction on dry and wet surfaces. The system peaks at 1200W, and reaches a top speed of 12mph over the course of a city block. The motor is wound pretty slow, which I feel is appropriate and I don’t want more speed.

I need about 400W to maintain a 10-12mph cruise on level ground. The machine is a beast to pedal, since I can’t match the 400 sustained watts of a motor. Though it runs and will carry a passenger or two, uphill starts can be tough and I’d like more power. I’m shifting to buy a 1500-2000W controller, since these are readily available and will hopefully provide enough pep.

 

[calab]

All that weight, you will have a problem with starting off on gravel with a front hub.
Carrying around 350lbs with a front 1500w leaf dd would spin easy, but you get the feel for things after you ride for a bit. You wont be going around corners fast on that thing.