My first ebike build: custom-built KMX-based electric velomobile

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The Toecutter   10 kW

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My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Feb 05 2021 12:59am

Pics of the bike:

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So far here's the realized specs:

-46 mph top speed on flat ground on a full charge with the motor enabled
-1,500W peak power, plus rider effort
-7 watt hours per mile @ 30 mph w/light pedaling
-9 watt hours per mile @ 35 mph w/light pedaling
-12 watt hours per mile @ 40 mph w/moderate pedaling
-12 watt hours per mile in the snow with enough effort to do 30 mph on flat ground, but riding at speeds from 20 to 40 mph with a 20 mph rolling average
-While powered yields a consistent 40-50 mile range with enough effort to cruise at 30-35 mph on flat ground in freezing weather. I get about 8.5AH from the 46.8V pack in the cold, although it is rated to 10.5AH. This should improve to perhaps 60 miles range at the same speed in warmer weather due to reduced air density and increased battery capacity.
-With the motor disabled, I can pedal it to 35 mph in a sprint and cruise on flat ground around 23 mph. I lost a few mph unpowered after installing the motor due to its additional weight and cogging losses.

At any operating speed with which it is capable, it feels stable and tracks straight. It has been up to 60 mph downhill before I motorized it and felt stable. It is very controllable at 30-40 mph in 30+ mph crosswinds with 50 mph gusts, although one will need a bit of effort to keep it straight in those extreme conditions.

Regarding what specs this will eventually have, I'm in the process of building another battery pack. It's going to be 72V 21AH, capable of delivering 5 kW peak, and is liable to give me a 150-200 mile range @ 30-35 mph, acceleration like a car(simulation shows 0-30 mph in about 5 seconds with a 96A phase current, but a better controller and a 150A phase current could allow 4 seconds), and a 70 mph top speed. I’m also going to finish a set of wheel fairings, a windshield, roof, and rear wheel cowling to cut drag further. I also plan to add brake lights, permanent running lights, headlight, and turn signals, as well as solar panels and a charge port for electronics. Later upgrades may also include hydraulic disc brakes, thicker brake rotors, and perhaps a rear suspension.

Here's some additional specs:

-Weight: 82 lbs
-CdA: Unknown
-Trike Frame: KMX framekit
-Body shell: Custom corrugated plastic bodywork with aluminum ribbing, mounts, and supports
-Battery: 46.8V 10.5AH pack of 13S3P Panasonic NCR18650GA cells, 490 Wh rated capacity, 1,500W rated peak power
-Motor: Leafbike 1500W 4T wind brushless PMDC motor, w/10k NTC thermistor and 10-12 awg bullet terminals, laced to 26" rear wheel w/13ga spokes and double-walled aluminum rim
-Controller: Phaserunner v3, currently set to 1,500W maximum power output, 750W maximum regenerative braking
-Computer: Cycle Analyst v3 DP, currently set to 1,500W maximum power output
-Charger: GrinTech Cycle Satiator HV model
-Torque sensor: Sempu 2-wire w/115mm spindle width, no throttle installed at the time
-Front wheels: Velocity 20" 32-spoke w/13ga spokes laced to double-walled aluminum rims
-Front tires: Schwalbe Marathon Greenguard 20x1.5" @ 95 psi
-Rear tire: Schwalbe Marathon Plus Tour 26x1.5" @ 60 psi
-Front crankset: Suntour XCT Jr. with 152mm crankarms, modified with 26/39/53T chainrings
-Rear gearing: SunRace 34-11T 7 speed cassette
-Front derailleur: Microshift Mezzo
-Rear derailleur: Shimano Tourney RD-TX35 7/8sp
-Chain: KMC Z7, lubricated with Boeshield
-Torquearms: custom KMX torquearm designed and made by ES member dhwahl(left-side), GRIN Torquearm Kit v4(right-side)
-Right shifter: Shimano Revoshift 7 speed index grip shift
-Left shifter: SRAM 3-speed index grip shift
-Front suspension: EXA gas shocks on upper/lower swingarms at 65 psi, suspension designed and made by ES member adam333
-Brakes: Avid BB7 calipers with 165mm disc rotors, cable-pull operated
-Right Brake lever: Terratrike dual-pull lever with parking brake
-Left Brake lever: GrinTech ebrake, operated for regenerative braking in the rear
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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Dauntless   100 GW

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by Dauntless » Feb 05 2021 3:02am

Are you sure you want to go 46mph in that? NO protection there. I see people with tadpoles who have a flag above eye level for the cars.

How are the steering and brakes?

And the third pic. Is there another vehicle in the distance?
Any sufficiently advanced technology is INDISTINGUISHABLE FROM MAGIC!
- Arthur C. Clarke

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The Toecutter   10 kW

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Feb 05 2021 2:35pm

Dauntless wrote:
Feb 05 2021 3:02am
Are you sure you want to go 46mph in that? NO protection there.
Of course I do!

What I don't want to do is WRECK at 46 mph, or really any speed for that matter. If one were to jump off of a 6 story building, they'd smack the pavement at close to 46 mph.
I see people with tadpoles who have a flag above eye level for the cars.
The wind points the flag straight back minimizing the visual cue exposed to any drivers from behind. My vehicle has about the same ride height as my electric Triumph GT6, and is about as readily seen. The flag in my case would be next to worthless and add drag. The real threat is boobus Americanus not looking at the road and texting on their phones.
How are the steering and brakes?
The steering is perfectly adequate, although an inexperienced rider might find it a bit "darty" since it is direct steering using the stock KMX steering bars. I keep my hands on both bars the vast majority of the time, and one must be mindful of possible loss of control with only one hand on the steering if road imperfections are encountered.

The brakes are solid and will panic stop reliably and straight up until about 35 mph with minimal worries, with my once a month inspection/adjustment. They get a bit questionable at anything faster than that, although I have done a panic stop at almost 50 mph before I converted it to electric. I was careening down a hill on State St into East St. Louis when the light at the intersection suddenly turned red with only a 1-2 second yellow. I had about 200 feet to stop, and got pulled towards a minivan in the next lane over at the first application of the brake lever, and had to carefully modulate application of the brake while adjusting my steering to stop quickly enough to avoid going through an intersection with 50 mph cross traffic, while at the same time avoiding a 3 foot concrete wall/divider/median on my left, and a minivan at 40+ mph on my right. The next chance I got, I pulled into a parking lot and re-adjusted the brakes, after letting the rotors cool down.

Installation of hydraulic brake calipers and dual-pull lever will correct this because of their self-balancing tendency. That is on the list of things to upgrade to when finances permit.
And the third pic. Is there another vehicle in the distance?
It's a plastic child's toy car with an open bottom, no pedals.
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by goatman » Feb 09 2021 12:51am

hitting bumps like train track crossings at 46mph, how does the front suspension handle it?

like your build :thumb:

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Feb 09 2021 9:58am

goatman wrote:
Feb 09 2021 12:51am
hitting bumps like train track crossings at 46mph, how does the front suspension handle it?
I haven't hit a railroad crossing at that speed. The rear wheel is unsuspended and there is a possibility that scenario could cause a loss of control. I plan to add a rear suspension when finances permit, which will entail.a redesign of the tail section to accommodate it..

For run of the mill potholes, speedbumps, and road debris, the front suspension exceeds expectations. As long as the rear wheel stays on smooth pavement, the front can hit anything and it feels like being in a cheap truck or a mid 20th century British sports car as far as ride quality.
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by goatman » Feb 09 2021 11:58am

weird how you lost the axle nut on the cassette side

i remember you saying you used a rusty bolt for the spacer inside the cassette, inside the drop out

i wonder if thats what made the axle nut loose

if you change the Regen torque ramp up rate in the phaserunner from 200ms to 400ms it wont hit on as hard, regen will roll on smooth

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The Toecutter   10 kW

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Feb 09 2021 12:16pm

I'm going to try that.

I plan to do long-distance touring with this thing, regardless of whether I soon end up homeless or not, so keeping this thing reliable is of utmost importance. It is neither easy to carry nor inexpensive to tow or ship.
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by goatman » Feb 09 2021 12:29pm

have you tried downloading phaserunner suite to your cell phone so you can make changes on the road

if you want faster acceleration, change the first setting

Torque Up Ramp to 50ms from 200ms
Last edited by goatman on Feb 09 2021 1:36pm, edited 1 time in total.

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by Chalo » Feb 09 2021 12:36pm

The Toecutter wrote:
Feb 09 2021 12:16pm
I'm going to try that.

I plan to do long-distance touring with this thing, regardless of whether I soon end up homeless or not, so keeping this thing reliable is of utmost importance. It is neither easy to carry nor inexpensive to tow or ship.
Recumbents generally are a bear to push for any distance, too. At least your pedal drive and motor drive are independent of each other.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Feb 09 2021 2:23pm

goatman wrote:
Feb 09 2021 12:29pm
have you tried downloading phaserunner suite to your cell phone so you can make changes on the road
I do not own a smartphone.
Chalo wrote:
Feb 09 2021 12:36pm
Recumbents generally are a bear to push for any distance, too. At least your pedal drive and motor drive are independent of each other.
This is the most significant motivating factor for adding a throttle. This way, if the bicycle drivetrain fails, I'm not stranded.
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by goatman » Feb 09 2021 4:54pm

The Toecutter wrote:
Feb 09 2021 2:23pm
goatman wrote:
Feb 09 2021 12:29pm
have you tried downloading phaserunner suite to your cell phone so you can make changes on the road
I do not own a smartphone.
Chalo wrote:
Feb 09 2021 12:36pm
Recumbents generally are a bear to push for any distance, too. At least your pedal drive and motor drive are independent of each other.
This is the most significant motivating factor for adding a throttle. This way, if the bicycle drivetrain fails, I'm not stranded.
smartphone doesnt have to be connected to a network, if you get one of your friends "old" smart phones you can hop onto free wifi somewhere to download it, then its just a matter of plugging the cell phone into the phaserunner

if you got a PAS potentiometer with your kit, it can be plugged into the throttle connector of the ca3 if your stuck in a pinch, it doesnt spring back like a throttle but it will get you home

https://ebikes.ca/ca3-aux-al.html

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The Toecutter   10 kW

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Feb 10 2021 12:00pm

goatman wrote:
Feb 09 2021 4:54pm

smartphone doesnt have to be connected to a network, if you get one of your friends "old" smart phones you can hop onto free wifi somewhere to download it, then its just a matter of plugging the cell phone into the phaserunner

if you got a PAS potentiometer with your kit, it can be plugged into the throttle connector of the ca3 if your stuck in a pinch, it doesnt spring back like a throttle but it will get you home

https://ebikes.ca/ca3-aux-al.html

I have a thumb throttle and briefly tested it on the trike in order to determine energy consumption figures at 30 mph without pedal input. It uses about 400W from the battery to do 30 mph on flat ground. So my pedaling is accounting for almost half of the energy requirement at that speed. It has since been removed. I'm trying to clean all the wiring up and am going to re-route everything so that none of the EV components are readily visible, with the exception of the CA3. I have a keyed on/off switch now(viewable in the 5th photo with the hood piece lifted; it's red with a black mount) so that the CA3 shuts off as well.

I'll see if I can find an old smart phone. A year and a half ago I bought one in anticipation of doing Doordash deliveries to make money, but the company said I was not needed as my zip code was saturated with employees. I've since given it away to a friend who needed one, but that person might hand it back. I'm not a fan of them, but keeping it in a faraday cage will nullify its objectionable traits, and it will be available when I need it.
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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The Toecutter   10 kW

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Mar 27 2021 6:07pm

I took a 30.4 mile ride today. Total energy consumption was 7.8 wh/mi from the battery according to the CA3. I was cruising at 30-35 mph as normal, and don't recall catching any red lights during the ride and had very few stops. This thing is very efficient.

I'm about to make a pack of two used Greenway 46.8V 15.6AH packs with BMS wired in parallel with each other and increase my range to 150 miles while only adding 9 lbs to the bike. I'll also be able to increase the power to 3 kW.
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Apr 05 2021 12:26am

The batteries arrived a week ago. A printout of their delivered capacity during testing from the seller was provided. They were 15.51 AH and 15.35 AH respectively. This means 30AH when I parallel the two together is a given.

I hadn't had much in the way of free time so I didn't get to fully install them. I need to make a wiring harness to parallel them together AND I need to make a custom enclosure to fit both of them lengthwise underneath the boom with their narrowmost dimension placed between the rotating pedals. Being a holiday weekend, all the places I could get the needed parts were closed, so I decided to devote the free time I had after 3pm today to testing the vehicle.

I was able to fit ONE of the battery packs underneath the boom. I used the higher capacity pack of the two, held to the boom with zip ties. To say I was pleased with the results would be to understate things. I rode it 83.6 miles, with cruising speeds of 30-35 mph plus pedal input. At the end of the ride, I had used 15.5 AH, and had consumed 8.7 wh/mi. The battery wasn't dead, but it was on the verge of being empty. I plugged in my charger for about 20-30 minutes at an outlet at a pavilion in a park, got a few AH back, and then rode it another 20 miles.

I now have a decent range EV!

Once I put both packs in, a 150+ mile range is assured. Plus it's very pedalable with a dead battery and I can leave spandex fetishists on roadbikes behind in most settings. I won't have any range anxiety using it to visit job sites anymore and won't have to charge it every day, and can opt to just change when it is convenient instead.
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by thundercamel » Apr 05 2021 9:14am

Very nice efficiency and range!
My Ebike builds - Existing bikes, affordable motor kits, self built 14s6p batteries - Now with more recumbent!

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » May 16 2021 12:09pm

I've been working so damned much with this new job I got 2 months ago that I've had no time to work on this between my job and caring for my mother who can't walk. I use it as my daily transportation and cannot currently take it out of commission for the multiple days I will need to make it to my friend's shop, hack the bike apart, and install a rear suspension. The amount of miles that have been placed on it since converting it into an EV early this year is approaching 6,000, and the KMX chassis is getting pretty damned tired as it will be hitting 60,000 miles sometime this year at the rate I'm racking up miles. Something's going to fail sooner rather than later, and all the creaks and groans the frame and seat rails and boom make when I'm riding it at speed are making themselves heard. adam333's front suspension is still holding up rock solid at least.

I am considering swapping in a 3T wind 1000W Leafbike motor to cut down on cogging losses when operated with the motor shut off, which will free my current 4T wind motor to be put into another trike. I do not have another trike yet, but am seriously considering purchasing a Milan SL Mk II or Mk III velomobile if I can find one(not many of them in the U.S. or Canada), mostly to use as a backup trike to get me to work so I can actually take the KMX out of commission to work on it, and also to study for design cues on the next iteration of my body shell being that the Milan is among the most aerodynamically efficient human powered vehicles commercially available. My current machine uses 400W to do 30 mph, whereas a Milan does it on 150W. However, I can't fit 2.5" wide solar race car tires on a Milan nor is the front track wide enough for it to be able to corner as well as a car without tipping over, nor is the suspension as robust as I would like, so it's not exactly the "ultimate" velomobile for my application. That one, I still have to build, but I think getting my wattage requirements down to 200-250W @ 30 mph is doable with improved aero, even with a wide track and lossier tires. The outboard wheels and panel gaps are really dirtying up the airflow and mine probably has 5-6x the aero drag of a Milan. That said, both the Milan and the WAW are the two velomobiles that most closely fit what I want to do, but the WAW's aero is nowhere near as good as the Milan and I'd probably not be satisfied with it.

I believe in going full retard on efficiency. The math I've done says a Milan could be set up with a street legal 750W 28 mph limited system and STILL be faster on an overall basis than my corovelo as it currently is when operated as a PAS. My CA3 suggests I'm putting out 200-250W with my legs when cruising at 35 mph with the motor doing the rest, whereas with a Milan, in a 28 mph limited system, I'd do like 35-40 mph on flat ground with 200-250W of pedaling and the motor adding nothing with a 28 mph cutoff. In a Milan, the motor would mainly be for going up hills and accelerating, but on flat ground, once I'm at speed, my legs will do all the work. I'd probably only need about 3-5Wh/mile in a milan, which would allow me a 150-200 mile range with just ONE of the Greenway 15.6AH packs in my possession. But the WAW would not be nearly as fast set up like that, although if I set up a WAW as I have my current corovelo with no speed limiter and a 1500W limit, it would then be faster than the corovelo. A WAW is obviously easier to work on than a Milan, so it has that going in its favor. My KMX velomobile has removable tail and nose, inspired by the WAW, which indeed makes it easy to work on, although unlike what I've read about the ease of removing body pieces on the WAW, it still takes me a few hours to remove the nose and tail pieces on my trike.

But now that I have the money to finish the KMX, I have no time to actually work on it. If I hack it apart to install a rear suspension and remove all the body pieces, it's going to be out of commission for at least 2 days if I actually had two contiguous off days to work on it uninterrupted, which would not be a good decision when I use it to get me to work and everywhere else. Nevermind the fact that I've never had 2 days of leisure time in the last two months anyhow and would probably have to split the work up over the course of weeks or a month. So an expensive velomobile purchase, just to have a backup trike, is very tempting right now...
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by goatman » Jun 13 2021 12:37pm

did you get a pattern online to cut the coroplast body

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Re: My first ebike build: custom-built KMX-based electric velomobile

Post by The Toecutter » Jun 13 2021 3:29pm

goatman wrote:
Jun 13 2021 12:37pm
did you get a pattern online to cut the coroplast body
No, but I do have a notebook full of pages with the dimensions of all of the cut pieces. That design is far from optimized. I was drawing up a 3rd design iteration that does away with the outboard wheels and will allow the airflow to be flush with the wheels, albeit the wheels won't be covered with the body. The sketch sort of looks like a mix between a Milan, a DF, and a WAW. It's designed with a removable nose and tail as well as easy serviceability in mind. AND because I want to add a gas shock in the rear and recline the seat back further to reduce frontal area and lower the center of gravity while extending the wheelbase, I will need to redesign the whole thing, but I can't do that until I have the trike frame physically in front of me assembled with the rear suspension and new layout to take measurements with which to make my next design.

My next velomobile may be a Milan SL. I'll be able to use that while I completely overhual the KMX.

I don't expect my next build will be as slippery as the Milan, BUT it can come close and I'll be sure to make it ready to handle highway speeds and 10 kW of power and it's going to have the storage space of a compact car. My next design will be more practical as well as faster than my current one. The Milan will act as a design guide should I obtain one. A friend of mine is currently setting a 3D printer up large enough to print a body shell in thirds, so I'll be able to make a nacelle with a roll cage that bolts around the KMX frame, and then bolt my nose and tail pieces to it.

As for the Milan, if I make the purchase, since I don't want to destroy it, I'm going to add a MAC geared hubmotor and restrict it to 750W, 28 mph, and 40A phase current. It will keep it street legal, and most of the time, I'll be on 100% pedal power somewhere over 30 mph, with the assist mostly used to get up hills and aid in accelerating up to speed. A 700Wh pack would probably give it a 150+ mile range in that usage case and it would still be very pedalable with the motor disabled without the cogging losses of my Leafbike motor. It would be every bit as fast as my current 1500W corovelo in that configuration, maybe faster.
Custom electric velomobile, 1500W: viewtopic.php?f=6&t=110298

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