My electric velomobile

[Ecky]

A geared motor shouldn't need a clutch, I would imagine. Not quite zero resistance but certainly a lot less than a direct drive.

Edit: beautiful velo btw.

[The Toecutter]

Originally Posted by Ecky

A geared motor shouldn't need a clutch, I would imagine. Not quite zero resistance but certainly a lot less than a direct drive.

I need it so that I don't have to pedal with the cogging torque losses when it shuts off over a set speed. The geared hub motor I want will have more cogging torque than the direct drive Leafbike in my custom build because it has thicker laminations. That cogging torque makes a big difference in how easy it is to pedal. The Milan only needs 150W of pedaling to do 30 mph, and the cogging losses of a MAC motor would likely be around 50W at that speed. If I have a clutch to decouple it, those losses are no longer a concern. This means the GMAC sold by Grin is not an option, since that is fixed with no clutch. That extra 50W would increase my speed to 35 mph on flat ground.

The idea being, that I could have a "street legal" ebike in most of the U.S. that can go well over the 28 mph Level 3 e-assist limit on flat ground and down hill while 100% human powered, but the motor will be available for accelerations and hills.

In Missouri, my custom build is legal due to a technicality in the legal code, but that may change next year. In Illinois, I have to limit it to 750W/28 mph to be legal. If I get a geared hub motor with a clutch on the Milan, I'll have all the assist I need for hills, AND be able to cruise at 35-40 mph most of the time, and be legal in most of the U.S. because the motor will shut off at the speed the law says it must.

In order to take the custom build apart for rebuilding/redesigning it, I need to get this Milan usable for the same purpose.

I'm eventually going to build a new shell for the KMX based on the Milan, add a roll cage, make some custom spindles that can accommodate cotter pin axles, add a rear shock, have Mitas MC2 moped tires all around, and turn it into a pedal "car" of sorts that can do 100+ mph, but still be pedaled to 40+ mph in a sprint with the motor disabled. This one won't quite be legal, but I'm going to have everything hidden so well no one will be able to tell it has a motor without taking it apart. I want to make a transportation appliance that gets around 20 Wh/mi at 70 mph, and can do 0-60 mph in 5 seconds or less.

Eventually, my plan is to build a completely custom platform dependent upon the success of this project, one that can accommodate a pure unmotorized velomobile of about 70 lbs, a "street legal" e-assist velomobile of about 85 lbs, an illegal high performance e-assist velomobile of about 100 lbs, and an AWD sports car with more than one horsepower per pound of vehicle with no bicycle parts of about 120 lbs.

[The Toecutter]

I now have a rear suspension kit for the KMX in my possession. I have not yet had the chance to install it.

Once I get a 20" wheel laced up to a 3T wind Leafbike hub motor, I'll be able to install it and then recline the seat further back and take measurements with which to scale the Milan's body shell around. I'm looking at taking the Milan's shape and widening it to fit the 39" front track, but keeping the airfoil proportions of the shell the same so that the air slips around it nicely. I'll have roughly the same height as the Milan, but about 25% more frontal area. I'll have wheels that are flush with the airflow and uncovered(think DF velomobile or Strada velomobile) to allow a smaller turning radius and easier access to the mechanicals for maintenance. Enclosing the wheels as the milan does and accounting for the steering clearances and suspension travel would necessitate a 48" wide body shell, so I'm going the unenclosed route for my wheels, but they won't be outboard. The ground clearance will also be around 5.5 inches, a full 2.5 inches more than my Milan.

If I pull this off and it has 2x the air drag of the Milan, that will mean that with the motor shut off and under pedal only operation, 225-250W required to do 30 mph using heavy duty solar car tires and accounting for the motor's cogging torque drag. Which would still be very pedalable with the motor disabled. Turn the motor on, and maybe 0.75-1 kW from the battery to do 60 mph. Which means a 1.5-2 kWh pack of 2170 cells from a Tesla Model 3 would go a long way to making this a practical vehicle with decent electric range at highway speeds, and would be a light enough battery that I could possibly keep the whole vehicle under 100 lbs which would mean its still light enough to pedal with the motor disabled, thus no such thing as range anxiety. AND the pack would be sufficiently small that a 110V outlet would be the functional equivalent of Level II charging, and a 220V outlet would be the equivalent of a Tesla Supercharger.

I also have sent a check to purchase a hydraulic brake system with both calipers activated by a single lever. I'm going to need it for the speeds I'm planning on riding at.

[The Toecutter]

Regarding the custom build, some months back I added in a second Greenway 15.6AH pack in parallel. I made a custom battery housing out of coroplast so that I can continue mounting the batteries below the front boom, and the box extends almost 1 foot ahead of the bottom bracket. I'm now getting a 150-200 mile range at 30-35 mph on a 1.5 kWh pack. The total weight of the vehicle is 90 lbs unladen.

I adjusted the max power setting to 2,500W. I've owned cars that were slower than this thing from 0-25 mph. 0-30 mph took about 6 seconds with hard full-effort pedaling, so there may have been about 3,200W total going to the drive wheel(CA3 said I was pedaling with 722W). I was able to do 45 mph up a moderate-grade hill on this setting, same as it can do on flat ground.

It feels deceptively stable at top speed: my Avid BB7 cable pull brakes are really at their safe/reliable limit for a predictable panic stop around 35 mph, even though I have panic stopped from much higher speeds(and it was quite harrowing to do so). I have a hydraulic brake system in my possession that is uninstalled, because I need to make a fluid reservoir for it since the stock one is woefully insufficient for the job, considering I'm not a fan of melting the brake lines from boiling brake fluid.

I am really looking forward to a much more powerful 72V/3T wind setup with full suspension, hydraulic brakes, sturdier tires/wheels, and a significantly more streamlined body shell. Right now, it's kind of dangerous. 35 mph is roughly the maximum safe cruising speed, even though it's capable of going faster.

[freebeard]

How do you plan to make the body shell?

[The Toecutter]

Once I get the rear suspension and new 3T wind Leafbike 1500W hub motor 20" wheel installed, I'm going to recline the seat further back(cut frontal area, lower center of gravity), then build a steel tube roll cage around the rider. A temporary body of coroplast will be wrapped around the roll cage.

The permanent body is going to be made out of vacuum molded carbon fiber or fiberglass. I'm going to make a mold and plug for it, and the midsection of the shell will fit like a clamshell with a left and a right side around the roll cage and then the two sides will be boned together.

The new shell is going to be heavily influenced by the Milan, but with a removable nose and tail piece as well as exposed wheels flush with the airflow on the sides, and a ground clearance around 5.5-6". So think a cross between a Milan, DF, and WAW velomobile. The nose will fit around the front section of the roll cage. The roll cage will not extend behind the roll bar(just behind the seat), in the interest of keeping weight down.

[freebeard]

A temporary body of coroplast will be wrapped around the roll cage.

May I humbly suggest you try my cutting pattern. Less seams. If the uncut lines are scored the result is faceted; if not it forms into shallow cones.

[The Toecutter]

For various reasons relating to clearances and my own vehicle's unique dimensions, I won't be able to use your exact pattern/dimensions, and will need to make a pattern similar to above that meets my own unique requirements. What software did you use to generate the above?

I might be able to generate a faceted nose piece and continue to the transition point between laminar and turbulent flow, at least, and keep the rest as simple as the previous design.

[freebeard]

I used Wings 3D at the time. Today I would recommend Blender. That form was sized for the Arcimoto FUV.

Any software that does UV mapping should work. That's the peel pattern used for texture mapping.

Here's another example from back then, more along the lines of your work.

[Grant-53]

See recumbents.com for the HPV body shell software. If you are going to register as a motorcycle trike there may be a 19 inch minimum seat height rule. Check your state DMV laws.