Want suggestions for cargobike with large mid-mount motor

[john61ct]

Anyone please

suggest a cargo platform frame that would be suited to Lighting Rod's XXL on the left side, including regen braking

with maximum possible use of pedal power on the right, maybe a belt, robust hub gear like Rohloff.

Don't care at all about looks, nor sporty "fun", sitting up straight, pure utility like the Dutch, also top speed at 20mph is OK

Able to accommodate "pretty fat" tires, not sure what if any suspension

Wheels can't be under 24-26" OD, rough gravel / fire roads, desert terrain sometimes, so looking for puncture resistance, moto rims?

but biggest challenge is torque, carrying 500+ pounds up long steep mountain roads

yes a huge Ah capacity pack is required, so maybe 600 pounds if I keep gaining weight.

Top priority is robust reliability, repairability easy as possible in remote "third-world" conditions

Thanks in advance

 

[SlowCo]

What is the cargo that you need to transport up the hill in size and weight?
How steep is the hill?
How are you transporting it now?
Does it have to be based on a bicycle?
What is your ability to build anything in skills, tools, knowledge?
Why have you been asking this off topic information in other peoples topics for years?
Why haven't you started a build yet?
Why are you repeating this dream/idea for so long? Sort of an OCD?

 

[Chalo]

Suggest a cargo platform frame that would be suited to the XXL on the left side, including regen braking

What do you mean by "the XXL"?

A direct drive hub mounted Stokemonkey style in the middle bay of a longtail frame like Yuba Mundo or Surly Big Dummy would allow you to use up to about 3:1 reduction.

 

[fatal14]

They created a new topic from a post in the lightning rod thread. It is the new XXL IPM motor (mid drive).

 

[Chalo]

They created a new topic from a post in the lightning rod thread. It is the new XXL IPM motor (mid drive).

That's the wrong motor for low output RPM. Furnishing enough gear reduction to reconcile that motor with the described use case will make a complex, noisy, unreliable, unpleasant bike.

If you want low RPM and high torque, start with a motor than does those things.

 

[ebike4healthandfitness]

Have you reached out to the people that make the drive yet?

P.S. Agree with a stokemonkey type arrangement. I got great results in the simulator even with a 2:1 reduction using a 35mm stator DD hub (See my previous thread https://endless-sphere.com/forums/viewtopic.php?t=109778 ). Going 3:1 reduction with a 45mm or 50mm stator hub should handle anything.

(One thing I have noticed playing around with ebikes.ca motor simulator is that increased internal resistance lowers torque as the rpm climbs. So perhaps think of that when designing your battery and picking your controller. Also if you went DD drive in stoke monkey arrangement consider how the faster hub RPM created by the reduction would work with Statorade.)

 

[ebike4healthandfitness]

John,

Take a look at this:

https://ebikes.ca/tools/simulator.html?motor=XF_DD45_3.5T&batt=cust_72_0.2_40&cont=cust_50_150_0.03_V&hp=0&mass=272&cont_b=cust_25_75_0.03_V&motor_b=XF_DD45_3.5T&batt_b=cust_144_0.2_20&mass_b=272&hp_b=0&bopen=true&mid_b=true&gear_b=6&tf_b=30&axis=mph&grade=0&grade_b=0&mid=true&tf=30&tr=30&gear=3

Doubling the voltage and halving the amps can work out nicely if you can efficiently double the reduction.

P.S. If I were to do the reduction I would keep the sprocket size on the hub motor the same and purely increase the size of the drive sprocket on the wheel. I would not reduce the size of the sprocket on the hub motor as a way to increase reduction. With that noted I am still learning on how gear reductions are optimized for efficiency. Obviously a very straight chainline is essential. Maybe someone else can chime in to help?

 

[Chalo]

With that noted I am still learning on how gear reductions are optimized for efficiency. Obviously a very straight chainline is essential. Maybe someone else can chime in to help?

Straight chainline, biggest possible sprockets to get the desired ratio, replace chain when it shows 0.5% longer than new, faithful lubrication. That and wish for the best.

 

[ebike4healthandfitness]

but biggest challenge is torque, carrying 500+ pounds up long steep mountain roads
yes huge Ah capacity pack required, so maybe 600 pounds if I keep gaining weight.

How steep are these roads?

If you measure the steepness of your route (a phone app that measures grade is good enough) you might find you don't as much motor as you thought you did. With that mentioned I do get it that sometimes buying overkill can be worth it for durability, but then again common level hub motors are easy to find parts for and might be more durable than you think.

 

[dogman dan]

Not your mid mount motor, but you really need to learn to weld. Practice on junk bikes at first, learning to get the rear wheel straight. Then build your bike with the frame designed specifically for carrying a lot of battery.

This was my solution, 2000 wh fit in the two slots in the frame, with additional 2000w or more possible in the panniers. Yes, it had a sturdy hitch for towing. Though the hubmotor was only a 500w, it was quite capable of getting up 8% grade with 400 pounds. 100 of it the bike, 200 of it me, 100 in cargo. Thats a lot of cargo for a camping outfit, but I needed to also carry a couple gallons of water.

The key thing here on this bike is the 20 inch rear wheel. This is your low gear, making a mid drive less needed. But this bike was designed for paved. It wasn't going to be asked to carry that trailer up a dirt fire or logging road.

You could build something similar, but instead of stokemonkey style, build it whizzer style. Take your motor, hub or whatever, and put a pulley on it. Then belt drive it to the rear wheel, in a nice low gear. Aim for a high rpm on the motor, and 15 mph on the wheel. Building it like a whizzer will eliminate the problem of making bike chain stand all that torque.

But I still think a good strong hub motor, in 20" wheel, will do er just fine. The real problem is to carry all that battery.

 

[spinningmagnets]

A large motor can take a lot of amps. And even though a motor this size might be more efficient at a higher voltage, going large is one way to get more power when you choose to limit your system to 48V/52V. (Just a thought)

A large 52V pack can be a backup for your home, to power a 120V AC inverter.

A 3:1 reduction can raise the rotor RPMs so the magnets tangential speed is higher, which is good. Just like putting a large diameter hubmotor in a 20-inch wheel, but "more".

If regen is vital, then use a solid sprocket on the left side.

I can't think of any factory frames that are already set up for this, and I agree with Dogman, you could put together two steel frames (by a variety if methods). Once you have verified that it will work the way you like, get it welded up.

 

[E-HP]

A large 52V pack can be a backup for your home, to power a 120V AC inverter.

This has been difficult for me to find. Do you know of any sources?

 

[MoneyPit]

At 500-600 lbs, you are beyond the 'rated' limits of commercial frames with the exception of, I think, something from Yuba. I forget the model name but its rated to 550. Put the biggest fat custom wheels on it you can muster and you should be able to get to 600.

My Surly BFD has gotten up to 560 or so. Thats waaay beyond its capacity and I did it on smooth streets. Balancing a bike with that kind of weight is a big (BIG) deal. You need to go slooowww to be remotely safe as you can't react well to any kind of surprise on the path in front of you. I peaked at about 8 mph. I have seen people put 30+ ah batteries on the superstructure just behind the seat. I have a shelf there myself but my 20ah pack is in the triangle.

That bike now has 90mm carbon fiber triangular/deep dish rims rated for 250kg each (from Nextie), with strong spokes and uber hubs (DT350 ratchets). I hated to spend the money but I could find nothing with a capacity approaching those. Also custom wideloaders which are critical to me being able to carry that load at all. Don't forget the really strong dual kickstand cuz loading that at a standstill is a party all by itself.

I heard some talk that came from the honchos at LarryvsHarry, where they noted that bike's frame can take it well past its 400 lb rated limit, but the true limiting factor was the tires. Not the frame, not the wheels... the tires. I have to say, trying 450-500 lbs with a mid tail that had 2.8" tires on MTX39's, then going bigger with the BFD with 4.3" tires on 80mm rims, no two ways about it you want to go fat. Lots of sidewall, lots of air pressure.

You can do it with less rubber, but you'll be a lot happier going full fat.

edit: maybe not totally fat. My original pictured 80mm Surly stock rims plus the very strong Edna 4.3" (for reals, not measured by the marketing department) tires allowed access to every cog in the back, which I up'd to a 46T. I have a 36T chainring up front and now use that bike to gather wood up in the mountains. With the 90mm rims and 4.8" tires I lose the big cog in the back. I run either tubeless (Nextie) or 5.05" tubed (Surly) with FlatOut inside and have had punctures that self sealed, including a 6-nail strip from a nailgun on the tubeless wheels. Bring a battery powered compressor for when that happens cuz they will seal but you will have to refill a few times before they do.

 

[ebike4healthandfitness]

Another alternative to using a mid mounted hub motor as a left side drive is to use a "Can motor" where the outer shell doesn't move and only the output shaft does. Some examples are the Astro 3220 or the ones on this page from QS motor:
http://www.cnqsmotor.com/en/article_list/QS%20Mid%20Drive%20Motor/107.html

One thing I like about these shaft drive motors is that they typically come with much bigger phase wires than the hub motors.

Here is a 2000 watt model with an output shaft for a belt drive:

http://www.cnqsmotor.com/en/article_read/QSMOTOR%20120%202000W%20Mid%20Drive%20Motor%20With%20Belt%20Shaft/986.html

Here are the torque, power, and efficiency curves (vs. rpm on the x axis) for the version not using the internal 4.77 to 1 gear reduction:

 

[SlowCo]

I love how active the OP is in other peoples threads asking off topic about this pipe dream nonsense hill climb bike project but hasn't bothered to answer any questions or react to all the advice given here in this thread made for him... :lol:

 

[ebike4healthandfitness]

At 500-600 lbs, you are beyond the 'rated' limits of commercial frames with the exception of, I think, something from Yuba. I forget the model name but its rated to 550. Put the biggest fat custom wheels on it you can muster and you should be able to get to 600.

My Surly BFD has gotten up to 560 or so. Thats waaay beyond its capacity and I did it on smooth streets. Balancing a bike with that kind of weight is a big (BIG) deal. You need to go slooowww to be remotely safe as you can't react well to any kind of surprise on the path in front of you. I peaked at about 8 mph. I have seen people put 30+ ah batteries on the superstructure just behind the seat. I have a shelf there myself but my 20ah pack is in the triangle.

That bike now has 90mm carbon fiber triangular/deep dish rims rated for 250kg each (from Nextie), with strong spokes and uber hubs (DT350 ratchets). I hated to spend the money but I could find nothing with a capacity approaching those. Also custom wideloaders which are critical to me being able to carry that load at all. Don't forget the really strong dual kickstand cuz loading that at a standstill is a party all by itself.

I heard some talk that came from the honchos at LarryvsHarry, where they noted that bike's frame can take it well past its 400 lb rated limit, but the true limiting factor was the tires. Not the frame, not the wheels... the tires. I have to say, trying 450-500 lbs with a mid tail that had 2.8" tires on MTX39's, then going bigger with the BFD with 4.3" tires on 80mm rims, no two ways about it you want to go fat. Lots of sidewall, lots of air pressure.

You can do it with less rubber, but you'll be a lot happier going full fat.

edit: maybe not totally fat. My original pictured 80mm Surly stock rims plus the very strong Edna 4.3" (for reals, not measured by the marketing department) tires allowed access to every cog in the back, which I up'd to a 46T. I have a 36T chainring up front and now use that bike to gather wood up in the mountains. With the 90mm rims and 4.8" tires I lose the big cog in the back. I run either tubeless (Nextie) or 5.05" tubed (Surly) with FlatOut inside and have had punctures that self sealed, including a 6-nail strip from a nailgun on the tubeless wheels. Bring a battery powered compressor for when that happens cuz they will seal but you will have to refill a few times before they do.

Maybe he should consider a trike? Perhaps a trike conversion that bolts up to a bicycle's rear drop outs?

I bring this because this would allow more common tubes, tires and rims.....plus more room for stuff. Easier to balance, of course.

Maybe it could even be a "long tail trike" by adding an intermediate frame extender in between the bicycle drop outs and the trike conversion forks (a single speed example of which is shown below)

 

[SlowCo]

Anyone please

Could you answer the questions and comment on all the good advice?

 

[ebike4healthandfitness]

Here is a trike conversion with an added left side drive:

 

[ebike4healthandfitness]

Here is a trike conversion with dual disc brakes and derailleur hanger:

(One thing I like about this arrangement is that even though front disc hubs are being used for the rear wheels they can still be built dishless (because they don't need to be centered in a fork). This means the right and left spoke tensions on each rear wheel can be equal to each other.)

 

[ebike4healthandfitness]

A trike conversion dually:

https://youtu.be/6s9LnVTaMo8

 

[999zip999]

Ebike for health and fitness. talk to text. Ok do you have links where you can get those rear ends if not there just Photoshop.
Hey Justin why don't you have a form for tricycles ?

 

[calab]

The pic does look photo shopped but the video is much better. I like the belt/chain driving the rear axle, install a mid motor would work very very well in harder climates, snow, ice, mud, sand. Even better is that same idea, but with 20x5" tires (if theres such a thing, may have to go 24" x 4) that would be fuckin awesome as shit :thumb:

 

[ebike4healthandfitness]

The first picture is for a very common Amazon and eBay kit. You can find this one everywhere. Just do an internet search for "bicycle trike conversion kit".

Here is the link for the second kit:

https://www.pistonbikes.com/Motorized-Trike-Conversion-Kit-p/mtck.htm

Link for third kit:

https://www.tricycleconversionkit.com/product-page/tricycle-conversion-kit-tricycle-conversion-kit-7-speed-and-disc-brake

Link for last kit:

https://higleywelding.com/select-product-catagories/ols/products/bicycle-3-wheel-conversion-axle

Edit: Found this one for the last kit as well-----> https://higley.bike/

 

[MoneyPit]

Maybe he should consider a trike? Perhaps a trike conversion that bolts up to a bicycle's rear drop outs?

I was thinking on this during the day today and really what he wants to do is too much for a 2-wheel cycle. That trike assembly looks super interesting.

I was thinking along the lines of a trailer. An uber trailer. Specifically something along the design lines of a Carla Cargo.

The price of these things factory made is beyond belief at $4500 for the non motorized version. I saw a guy building his own and it came out great.

- 3 wheels for stability. Go fat 20" and raise it up some for a more trailhappy version.
- put a hub motor on the front wheel
- replicating the overrun brake might be a little bit of a challenge but probably not for someone who knows their way around electrical fabrication.

20" fat parts are a dime a dozen.

Going with a bigass trailer like this means you have a whole lot more options for the towing bike.

 

[calab]

Thanks for the links, its about the same price as a cheap bso trike from mr waltons mega store.

The first picture is for a very common Amazon and eBay kit. You can find this one everywhere. Just do an internet search for "bicycle trike conversion kit".

Here is the link for the second kit:

https://www.pistonbikes.com/Motorized-Trike-Conversion-Kit-p/mtck.htm

Link for third kit:

https://www.tricycleconversionkit.com/product-page/tricycle-conversion-kit-tricycle-conversion-kit-7-speed-and-disc-brake

Link for last kit:

https://higleywelding.com/select-product-catagories/ols/products/bicycle-3-wheel-conversion-axle