1,500 lb eTrike???

[Mossha150]

I’m looking for thoughts, suggestions and technical advice on the feasibility of building a custom (Christiania-type with two wheels in the front and one in the rear) vending etrike. I’m new to the forum and will do my best to explain what I’m trying to do in sufficient detail to garner constructive feedback and input. My technical knowledge of e-bikes is limited and so I apologize in advance if any information I provide or questions I ask sound a little ridiculous.

I’m trying to figure out how to build an awesome-looking etrike to sell cold and nitro brew along with other non-alcoholic beverages (maybe hot cocoa in the winter) on tap at local festivals and events here in Alaska. I’ve looked at the variety of manufactured vending trikes, however, they don’t quite meet my needs or desires.

My basic concept is to modify a steel frame fat bike to incorporate a chest freezer (converted to a refrigerated cooler), in which I can haul up to eight 5 gal kegs, a nitrogen tank and CO2 tank (if needed). Between the donor bike, modifications, chest freezer, kegs, LiFePO4 battery, rider, etc., I estimate the total weight would be upwards of 1,500 lbs. I’m not trying to build a tank but a fully functional unique mobile business.

If possible, I would like to use 26” fat bike wheels in the front and rear for something a little unique. For simplicity, I was looking at using Grin’s 8T slow wind All-Axle hub motors in the two front wheels, assuming I can make it work with direct drive hub motors. I would leave the rear drive train as stock (non-motorized) with the chain and cassette. I don’t need a lot of speed or distance, just a lot of torque I assume. I would plan to haul (trailer) the bike to the vicinity of the event and then pedal it the rest of the way into position.

I used Grin’s motor simulator and bounced the results off of Grin’s tech staff. While it appears the motors wouldn’t overheat, it’s unclear if they would be able to handle the massive load and if I would actually get much benefit from the motors. The Grin’s tech rep’s concern is finding a wheel setup capable of supporting that much weight and he pointed me to this community for input, so here I am. I realize there are a lot of details to figure out, but it seems the wheels and brakes are maybe the starting point of determining if I can make this work. So this brings me to my first few questions.

1. Is it even in the realm of possibility to find a fat tire rim and spoke combination that is capable of supporting 500-600 lbs per wheel?
2. If so, would an aluminum rim or carbon rim be better? I looked at Nextie’s double wall carbon rims, which are rated to support 440 lbs (200 KG) and it appears in their description of their Wild Dragon rim it may be able to support more than that, but they can’t say it’s rated for that load.
3. Would a wider fat tire rim be stronger than a narrower rim? If so, would you recommend a 65, 80, 90,100 mm or even wider rim?
4. What fat tires would I need to use? Can you insert foam or anything else inside the tires to increase their load carrying capacity?
5. If I have the option, would there be a benefit of using 20” fat tire wheels for the front two instead of 26”?
6. If there is a fat tire rim that would work, what gauge spokes would be recommended?
7. If a fat bike wheel won’t work, could you use a moped or motorcycle rims and still use Grin’s All-Axle hub motors?
8. Can I make this work with direct drive hub motors? Or do I need to find another solution?
9. If I can find bike wheels that will work, what is recommended for braking? Are bicycle disc brakes up to the task? Do I need to consider adapting motorcycle rotors. What about using regen brakes or ABS?

Regarding the electrical system, I’m looking at using a larger (5-7kWh) 48V LiFePO4 battery (like a Husky or Mustang unit from BigBattery.com) with an inverter to power the 120V chest freezer and other equipment and lights. And ideally the battery could power the etrike motors. I thought a heavy (100+ lb) battery strategically placed on the bike could help lower the center of gravity and improve stability.

Can you use a 48V LiFePO4 battery for an ebike? Are there any major issues or concerns with going this route? I thought a larger capacity battery would allow me to be self-sufficient all day and then recharge at home overnight.

Lastly (for now), could I pull a trailer with this etrike? If possible, I would like to have the option of pulling a trailer with another chest freezer to have an ice cream cart in tow and sell floats as well with the root beer on tap. The trailer would also have 26” fat tire wheels and another LiFePO4 battery (if needed) to run the freezer. If this would work, could you use hub motors in the trailer wheels for more power and help push the etrike?

I know it’s a lot of questions and I would appreciate any thoughts or suggestions. I would really Iike to figure out how to build a fun and unique etrike to help bring some joy to folks.

 

[Papa]

Lastly (for now), could I pull a trailer with this etrike?

Might be helpful?....

Project View

Grin Technologies

ebikes.ca

 

[nicobie]

I can't understand why you don't build a trailer to carry the beer. A bike that weigh 1500 lbs is too heavy for typical bike wheels.

 

[Chalo]

I don't think it's plausible to build a full sized wheel strong enough to reliably carry 600 pounds if the hub is an All-Axle. Maybe the strongest of BMX rims or double walled 20" fatbike rims could do it. But with a bigger wheel, there's just not enough bracing angle on the spokes to tolerate the side loads that those wheels will experience.

Using plastic rims is asking for expensive trouble-- the tension peaks on the spokes when you turn a corner or traverse a slope will delaminate that junk and tear the nipples through. The hoops themselves might or might not withstand the weight, but the spoke holes will fail.

Serious pedicab wheels can do what you want. But they are keyed to a differential axle that's usually 1" in diameter, and you'd have to drive the axle with a chain reduction rather than use hub motors. That would make it easier to get the wheel torque you need without burning the motor down, though.

 

[Mossha150]

Might be helpful?....

Project View

Grin Technologies

ebikes.ca

Papa, thanks for sending this over. I did see it on Grin’s site. While not the setup I‘m pursuing and half the weight, the info on the brakes was interesting.

 

[Mossha150]

I can't understand why you don't build a trailer to carry the beer. A bike that weigh 1500 lbs is too heavy for typical bike wheels.

nicobie, I considered that, however, I like the idea of being able to get into places in amongst a crowd with a bike, which would be difficult with food trailer. I’ve seen cargo bikes (in a different setup) that seem to push the 1,000 lb barrier, so I‘m thinking…why not? Thanks.

 

[scianiac]

I would build the frame suitably strong and setup the drive for a single speed low geared mid drive motor and a separate pedal system if you. So for instance use the back of a regular sturdy steel frame with a left hand motor drive geared to be quite slow because lets face it you aren't speeding around on this and with that much weight you'll want all the torque you can get to go up even a very small hill. Most of the weight will be on the front wheels which can be heavier pedicab, scooter, small motorcycle wheels etc. I would just go with like a Lightning Rods left hand drive with a massive rear sprocket but there are many other suitable motors. Just any motor with a reduction before the output so you have two total reductions. Think serious motor not some little middrive kit. Oh and using more serious wheels on the front also allows you to mount serious brakes as well which may be nice, I'm sure most places you'll be going are flat but it only takes one small hill you can't get up or safely down to be a problem.

 

[amberwolf]

If you're using a custom-built Christiana-type tadpole design that pivots at the center of the box with a single solid axle underneath, you could use a pedicab axle, wheels, etc., even a pedicab motor system (driving that axle), as long as your cargo/etc area can either be lifted enough above the axle (or have an upraised area inside it) to clear the sprockets, chains, etc.

That's probably going to be the "easiest" way to support the weight you're after, since pedicabs may carry up to several times the weight you're needing to, depending on their design, and so the wheels for those should be able to deal with the load, and you can buy them as complete spare wheels, axles, bearings, and drive system to build around.



The pedicab wheels are going to be easier to access for roadside wheel or tire problems, and you can simply carry a couple of spares on the trike to just jack up the cargo area and swap them right out.


There are a fair number of posts in my SB Cruiser threads (original and Mk II ponderings) regarding ups and downs of different setups; even though it's a delta vs tadpole like the Christiana, most of them still apply.


There are other similar-usage but functionally different designs like these that pivot from behind the cargo area instead of under it, to allow a lower deck, and don't have a pedicab-type live axle to drive the wheels from, so any non-hub drive would have to either drive the rear, or one on each front wheel, or a common axle somewhere under, behind, or in front of the cargo area that then chain, gear, or belt drives the actual wheels.

These would be more suited to typical hubmotor use than the single-ended axle trikes, since the axles would be supported on both sides...but finding a bicycle-sized hubmotor with an axle suited to the load might be tough. You can ask Grin Tech about their All Axle motors, to see if the motor itself can handle it, and then if necessary have axles and adapters made to mount them to your specific trike design.



Something to consider for any of the front-cargo designs like those is that it's likely to be pretty hard to manually turn it with such a massive front end, unless you are fairly strong. I don't have direct experience with them, but have dealt with pallet jacks and >half-ton pallets every week or two in a retail store, and if the steering wasn't done by the handle on the *rear* wheel, and was instead done by pushing on the actual pallet of stuff, I'm not sure I could actually turn them around the corners at all.

Either setting up some form of remote kingpin steering for the wheels under the cargo area, or Delta-ing the design and putting the load in the back and steering with the front wheel, would make it easier to handle.

 

[PaPaSteve]

Caution ...
While the wagon style steering system ( one pivot in the center of the front axle ) is a common method for an ice cream cart it can be a dangerous vehicle with speed, any off camber or high crown road situation.
We owned a Workman trike and found out the hard way. Luckily the injuries were minor.
I'd expect the front loading cargo design where the single steering pivot is placed behind the front axle to be even harder to control.
Those examples showing disc brakes on the front wheels is an excellent idea.
3/4" diameter front axle is probably the minimum
12 or 11 gauge spokes
Gear it very low

 

[nicobie]

I think you would be better off towing the beer. Spend some time figuring out what type of towing hitch to build and what tongue weight is appropriate.

 

[2Phast2Delirious]

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" .

 

[Mossha150]

I don't think it's plausible to build a full sized wheel strong enough to reliably carry 600 pounds if the hub is an All-Axle. Maybe the strongest of BMX rims or double walled 20" fatbike rims could do it. But with a bigger wheel, there's just not enough bracing angle on the spokes to tolerate the side loads that those wheels will experience.

Using plastic rims is asking for expensive trouble-- the tension peaks on the spokes when you turn a corner or traverse a slope will delaminate that junk and tear the nipples through. The hoops themselves might or might not withstand the weight, but the spoke holes will fail.

Serious pedicab wheels can do what you want. But they are keyed to a differential axle that's usually 1" in diameter, and you'd have to drive the axle with a chain reduction rather than use hub motors. That would make it easier to get the wheel torque you need without burning the motor down, though.

Chalo, thanks for the input and suggestion on wheels. I wasn’t familiar with pedicabs and inherently stronger rims. I will look into them. Sounds like stay away from carbon rims, good to know! Do you have any suggestions (make and/or models) for a good chain reduction motor setup?

 

[Mossha150]

I don't think it's plausible to build a full sized wheel strong enough to reliably carry 600 pounds if the hub is an All-Axle. Maybe the strongest of BMX rims or double walled 20" fatbike rims could do it. But with a bigger wheel, there's just not enough bracing angle on the spokes to tolerate the side loads that those wheels will experience.

Using plastic rims is asking for expensive trouble-- the tension peaks on the spokes when you turn a corner or traverse a slope will delaminate that junk and tear the nipples through. The hoops themselves might or might not withstand the weight, but the spoke holes will fail.

Serious pedicab wheels can do what you want. But they are keyed to a differential axle that's usually 1" in diameter, and you'd have to drive the axle with a chain reduction rather than use hub motors. That would make it easier to get the wheel torque you need without burning the motor down, though.

I would build the frame suitably strong and setup the drive for a single speed low geared mid drive motor and a separate pedal system if you. So for instance use the back of a regular sturdy steel frame with a left hand motor drive geared to be quite slow because lets face it you aren't speeding around on this and with that much weight you'll want all the torque you can get to go up even a very small hill. Most of the weight will be on the front wheels which can be heavier pedicab, scooter, small motorcycle wheels etc. I would just go with like a Lightning Rods left hand drive with a massive rear sprocket but there are many other suitable motors. Just any motor with a reduction before the output so you have two total reductions. Think serious motor not some little middrive kit. Oh and using more serious wheels on the front also allows you to mount serious brakes as well which may be nice, I'm sure most places you'll be going are flat but it only takes one small hill you can't get up or safely down to be a problem.

scianiac, thanks for the input. Just to make sure I understand your suggestion, would the single speed low geared mid drive motor, such as the Lightning Rod’s left hand motor drive, be used to drive the single rear wheel or the two front wheels? Also, are there other brands of quality mid drive reduction motors I should look at as well? And do you have any specific thoughts on pedicab vs. scooter vs. motorcycle wheels? Does one make more sense than the others? Currently, I’m looking at starting with a Mongoose Malus steel frame as a donor bike for the rear end. It appears others have made some minor upgrades in the drive drive to get more gears and better setup. Then I was going to use tube steel to weld up a new custom front end. If it make sense, I could use aluminum T-slot framing (to reduce weight) for anything mounted above the front end chassis. I’m assuming whatever I use for wheels, should be supported on both sides of the axle, and not a single-sided application. Any thoughts?

 

[PaPaSteve]

Have you looked into the vending rules and permits for your local ?
A couple friends wanted to do pedicab rides at festivals and found the permit and insurance made the idea unfeasible.

 

[scianiac]

Driving the single rear wheel would be easier as you wouldn't need a front differential and based on the configuration I think the weight transfer to the back up a hill should provide enough traction although someone with more experience with heavy bikes may want to chime in. I suggested an LR kit because it's probably the best balance of cost, simplicity, reliability, and easy of installation. Assuming the frame will fit the motor nicely it would be pretty simple to install and Mike would be able to help spec a unit fit for your purpose, possible with more gear reduction.

As for wheels others have a lot more experience than I. I don't agree with Chalo on everything but the man knows his wheels.

But realistically you should look into possibly just adapting something or stealing parts from something that is already closer to what you are looking for unless you're in it for the fun of building it from scratch. Like there are already things pretty similar to this you could rearrange, use the whole axle, wheels, motor, assembly from something like an electric pedicab. Or even start with the trailer and a much smaller vending setup and build from there. It sounds like you are really interested in both building and using the thing so maybe doing less building and more using at first and then going from there.

The way I look at it is people very often have some big plan for some project and envision how it will work and so they set out on it, spend way way too much time on to the point of it not being fun anymore and then the end product doesn't work well, assuming they finish it, because it was all based on theory. I personally enjoy the building more than the using often and still I build something in a sort of minimum viable state then test it and then go back and improve it. Overall the end result is much better, it's a lot more fun and rewarding having the project work and then improve it to be perfect than have it kinda work but with a million things you would have done different.

In this case the use is of course vending delicious beverages but do you really know the best way to do this? Do you really need that many kegs? You want it to be maneuverable but also look how big and heavy it will be, maybe just 2 kegs with a more compact chiller and CO2 tank will work better, perhaps in a trailer or cargo bike which could be much narrower. Maybe you'll find it's easier to have that and then just go back to a truck or van where you can swap the kegs out half way through an event. You don't even need to start with an Ebike for something small. Or maybe you'll find the conditions are a lot rougher at some of these events and you'll need to build something with a bit more off road capability to deal with mud and wet grass or some serious hill climbing power.

 

[Mossha150]

Caution ...
While the wagon style steering system ( one pivot in the center of the front axle ) is a common method for an ice cream cart it can be a dangerous vehicle with speed, any off camber or high crown road situation.
We owned a Workman trike and found out the hard way. Luckily the injuries were minor.
I'd expect the front loading cargo design where the single steering pivot is placed behind the front axle to be even harder to control.
Those examples showing disc brakes on the front wheels is an excellent idea.
3/4" diameter front axle is probably the minimum
12 or 11 gauge spokes
Gear it very low

Thanks for the thoughts on the challenges and concerns with controlling this kind of setup. I will take that into account. It seems like a large 3/4”-1” front axles are the way to go. I‘d be curious what 20 mm thru-axles are capable of carrying for a load.

 

[Mossha150]

If you're using a custom-built Christiana-type tadpole design that pivots at the center of the box with a single solid axle underneath, you could use a pedicab axle, wheels, etc., even a pedicab motor system (driving that axle), as long as your cargo/etc area can either be lifted enough above the axle (or have an upraised area inside it) to clear the sprockets, chains, etc.

That's probably going to be the "easiest" way to support the weight you're after, since pedicabs may carry up to several times the weight you're needing to, depending on their design, and so the wheels for those should be able to deal with the load, and you can buy them as complete spare wheels, axles, bearings, and drive system to build around.

View attachment 346706 View attachment 346707 View attachment 346710

The pedicab wheels are going to be easier to access for roadside wheel or tire problems, and you can simply carry a couple of spares on the trike to just jack up the cargo area and swap them right out.


There are a fair number of posts in my SB Cruiser threads (original and Mk II ponderings) regarding ups and downs of different setups; even though it's a delta vs tadpole like the Christiana, most of them still apply.


There are other similar-usage but functionally different designs like these that pivot from behind the cargo area instead of under it, to allow a lower deck, and don't have a pedicab-type live axle to drive the wheels from, so any non-hub drive would have to either drive the rear, or one on each front wheel, or a common axle somewhere under, behind, or in front of the cargo area that then chain, gear, or belt drives the actual wheels.

These would be more suited to typical hubmotor use than the single-ended axle trikes, since the axles would be supported on both sides...but finding a bicycle-sized hubmotor with an axle suited to the load might be tough. You can ask Grin Tech about their All Axle motors, to see if the motor itself can handle it, and then if necessary have axles and adapters made to mount them to your specific trike design.
View attachment 346708


Something to consider for any of the front-cargo designs like those is that it's likely to be pretty hard to manually turn it with such a massive front end, unless you are fairly strong. I don't have direct experience with them, but have dealt with pallet jacks and >half-ton pallets every week or two in a retail store, and if the steering wasn't done by the handle on the *rear* wheel, and was instead done by pushing on the actual pallet of stuff, I'm not sure I could actually turn them around the corners at all.

Either setting up some form of remote kingpin steering for the wheels under the cargo area, or Delta-ing the design and putting the load in the back and steering with the front wheel, would make it easier to handle.

amberwolf, thanks for the thoughts and suggestions. Others have also suggested pedicab wheels, which I was unfamiliar with. I will definitively have to look into them. I was concern about the steering and my ability to make it work. Sounds like I have some more to figure out.

 

[PaPaSteve]

Seat of the pants engineering says 20mm axle would work out OK provided the material is a decent grade.
Here's an example of 20 mm thru axle mountain bike hub with disc brake held in place with a 5/8" grade 8 bolt using a spacer to adjust for the difference in diameters.
As part of the design process we did a static load test by added bags of concrete until the tires were completely compressed with the rim at the point of cutting the tire.
Sorry . . . I don't recall the total amount of weight but it probably was more than your 1,500 pound design parameter.
Nothing on the trike sustained any damage.

 

[jetpackjbd]

I’m a bit late to this thread; I’m more confused as to why you’d need a freezer… in Alaska. Even if it’s not powered, do you really need an insulated container? Outside of your short summer season, I’d think you’d need a heater instead to prevent anything from freezing. You’d know more about the temperatures than I would, so I can’t question it.

Anyways, the main issues I see with your original concept are as follows:

-Spoked rims are generally not meant for heavy loads, I think they top out around 300 pounds each. You could certainly try but I wouldn’t recommend it.

-I can’t find anything about foam tires increasing wait capacity, although I do know that a softer or lower pressure tire will hold more weight than a harder or higher pressure one. Even with softer tires, the metal rim can only hold so much.

-An electric motorcycle hub motor might work for your application, as I’m pretty sure that’s the closest thing to a spokeless bike wheel with a powerful hub motor in it.

- A 48V system might be harder to work with, as you’ll be pulling quite a few amps to move 1,500 pounds. A 72V or 96V system might be more ideal. There’s more parts for 48V systems and I know that they still make 2000+ watt motors for 48V, but if you want any more power than that you’ll want to consider a higher voltage.

-Disc brakes may work fine but if you can get a motor with regen braking as well that would be ideal. ABS would be nice if you’re driving on snow but I’m not sure if that’s something you’ll be able to realistically do yourself.


Honestly, unless you really want to avoid registration, I’d suggest just making an electric utility vehicle, ATV, or snowmobile instead if you’re set on carrying that much weight. Maybe converting an old Honda 3-wheeler might fit your need for a trike.

 

[Mossha150]

Have you looked into the vending rules and permits for your local ?
A couple friends wanted to do pedicab rides at festivals and found the permit and insurance made the idea unfeasible.

PaPaSteve, good point. I have discussed it with the State Health Dept, but I should check on the legality issues for the business licensing of the mobile food business and the vehicle licensing of the etrike, which may be more challenging.

 

[Mossha150]

Seat of the pants engineering says 20mm axle would work out OK provided the material is a decent grade.
Here's an example of 20 mm thru axle mountain bike hub with disc brake held in place with a 5/8" grade 8 bolt using a spacer to adjust for the difference in diameters.
As part of the design process we did a static load test by added bags of concrete until the tires were completely compressed with the rim at the point of cutting the tire.
Sorry . . . I don't recall the total amount of weight but it probably was more than your 1,500 pound design parameter.
Nothing on the trike sustained any damage.
View attachment 346750

Thanks for the feedback. That helps me have an idea of where maybe to start or what’s in the realm of possibilities. Great looking trike. Am I correct in understanding your 5/8” Grade 8 bolts with spacers for axles were a single-sided wheel mount application and you still loaded it over 1,500 lbs?

 

[PaPaSteve]

Thanks for the feedback. That helps me have an idea of where maybe to start or what’s in the realm of possibilities. Great looking trike. Am I correct in understanding your 5/8” Grade 8 bolts with spacers for axles were a single-sided wheel mount application and you still loaded it over 1,500 lbs?

Correct

BTW . . . the pedal powered ice cream vendors use a chunk of dry ice to keep the items frozen.
During the COVID shut down we did a coast to coast trip carrying extra food in a large ice chest as an effort to avoid being in stores etc.
9 pounds of dry ice combined with an occasional 7 pound ice bag lasted nearly one week.

 

[Mossha150]

I’m a bit late to this thread; I’m more confused as to why you’d need a freezer… in Alaska. Even if it’s not powered, do you really need an insulated container? Outside of your short summer season, I’d think you’d need a heater instead to prevent anything from freezing. You’d know more about the temperatures than I would, so I can’t question it.

Anyways, the main issues I see with your original concept are as follows:

-Spoked rims are generally not meant for heavy loads, I think they top out around 300 pounds each. You could certainly try but I wouldn’t recommend it.

-I can’t find anything about foam tires increasing wait capacity, although I do know that a softer or lower pressure tire will hold more weight than a harder or higher pressure one. Even with softer tires, the metal rim can only hold so much.

-An electric motorcycle hub motor might work for your application, as I’m pretty sure that’s the closest thing to a spokeless bike wheel with a powerful hub motor in it.

- A 48V system might be harder to work with, as you’ll be pulling quite a few amps to move 1,500 pounds. A 72V or 96V system might be more ideal. There’s more parts for 48V systems and I know that they still make 2000+ watt motors for 48V, but if you want any more power than that you’ll want to consider a higher voltage.

-Disc brakes may work fine but if you can get a motor with regen braking as well that would be ideal. ABS would be nice if you’re driving on snow but I’m not sure if that’s something you’ll be able to realistically do yourself.


Honestly, unless you really want to avoid registration, I’d suggest just making an electric utility vehicle, ATV, or snowmobile instead if you’re set on carrying that much weight. Maybe converting an old Honda 3-wheeler might fit your need for a trike.

jetpackjbd, despite the rumors, it does actually get warm in the summer up here. I‘m about 40 miles north of Anchorage where it 75-80 degrees is very warm to us (don’t laugh). If you go farther north in the interior toward Fairbanks, it can get over 90 degrees. If I want to keep beverages around 33-34 degrees, I need mechanical refrigeration, especially if I’m out all day (up to 20+ hours in the peak of summer). But you’re right, in the non-summer months, I would like to see if I can convert my chest freezer refrigerator (keezer) into a heated box to keep hot beverages in kegs warm, such hot chocolate.

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.

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.

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.

Thanks for all the input!

 

[Mossha150]

Correct

BTW . . . the pedal powered ice cream vendors use a chunk of dry ice to keep the items frozen.
During the COVID shut down we did a coast to coast trip carrying extra food in a large ice chest as an effort to avoid being in stores etc.
9 pounds of dry ice combined with an occasional 7 pound ice bag lasted nearly one week.

Thanks for confirming. I’ve consider non-mechanical refrigeration, just not sure if I can get the temperature control I may need for beverage dispensing out of taps without it freezing. It’s definitely worth considering for my ice cream trailer, where frozen is good!

 

[Chalo]

And do you have any specific thoughts on pedicab vs. scooter vs. motorcycle wheels? Does one make more sense than the others?

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.