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

I just read the whole thread. Good stuff!
I have a similar dream/project in mind soo will be following this.

You may want to search ' Windows Ameliorated ' Toecutter.
It's been a while as I use Linux now, but IIRC its Win10 (free) with all the crud removed, or you can opt for a crud remover for the original download.
Then there's Malwarebytes Windows Firewall Control (WFC) that makes looking up (WHOIS etc) then blocking/allowing any file trying to 'phone home' very convenient and quick. Also free.
 
As the top of a wheel is heading into the wind at twice the speed of the bike itself and as aero drag goes up with the square of wind speed; These Aerodefender mudguards make a lot of sense:
https://www.bikeradar.com/news/null-winds-technology-fairing

(I NB that they don't cover more of the wheel as that would cause unacceptable instability in cross winds, so you only want too cover the bit of wheel moving more/mostly into the wind)

They look ass on a bicycle, but I think that on a velomobile with outboard or open front wheels something similar may actually look pretty good.
Both the front and rear models should look even better on any recumbent bike, but thats a matter of opinion.

The spoke 'fairing' things in the pics look pretty ass too but the physics makes sense on anything doing more than 20mph? most of the time.
As they weathercock, they will ameliorate side winds some vs a std spoked wheel while actually providing a modicum of forward thrust if very slightly sprung to 'return to center'.
I think a better, more aero, slightly sprung, carbon/glass fiber 'Spoke Sleeve' thing would be a goood idea for aero enthusiasts and any fast moving bicycle, like E-bikes, in general.
 
The new super-fast wind all-axle motors have been ordered.

I look forward to making this thing into something truly retarded. LFP once told me he'd like to see me have 20 kW in it. So maybe sometime in the near future, it will! The 20S6P battery I put together with Agnuism's weldless kit and some Molicel P42A can do that, continuously. I haven't tried to get more than 10 kW from it yet, but should it hold up to 20 kW, I may very well permanently spot weld the pack together with copper sheet and nickel strips. The BAC4000 can run field weakening, so I can make my rear 17.5kV Leafbike 1500W 3T match what will be 20kV Grin All-axle side 3T motors up front in speed. 72V may well be enough for 90 mph or thereabouts, which is plenty.

Wassup bud!, long time no post here.. you've been busy!

A word of caution from my "I almost died" personal experience in regards to doing these insane speed test: "you only live once, and its all fun and games until you are dead" trust me, it can happen, and it happens FAST.

I gave up on three wheeled vehicles last year after a snap rollover on my A-3 trike at "just 25 mph" (a trike that was enclosed, and I was wearing a full helmet, and I think being 25 mph and not 50 mph is probably the main reason why I lived to tell the tale) due to an unexpected rear wheel lockout while taking downhill off-camber right turn.... and it flipped... so fast... I didn't have time to do anything but watch the world go upside down in slow motion before crash landing.... that was the day I decided to go 4 wheels. No regrets.

Since then, I've rebuilt two of my three trikes into quads. Never going back to 3 wheels EVER for anything that isn't just leisure riding around the bike paths at 10 mph.

A-1, after a full frame realignment, sandblasted, rust treated, and fully repainted... its now back on the roads as my daily driver in quad form, with minimal fairing from its former self. It is still running the original 3kW Cyclone on it... and it has clocked over 1500 miles as a quad already. It had over 14000 miles as a trike before the rebuild.
A-3 has a giant 8kW Cyclone true mid-drive motor behind the seat. Less than a mile since I am still working on it... it had around 3000 miles before the accident and rebuild.
A-2 still a trike, pretty much the same as it looked back in 2016... but finally got its front suspension/fenders a few weeks ago... still looks pristine, and has less than 1000 miles on it: not a hint of rust anywhere.

With 4 wheels, 4 hydraulic over-sized downhill brakes plus an LSD differential it can take the tightest roundabouts at well over 40 mph, something I wouldn't dare to try on a trike before going on two wheels and crashing. It brakes on a dime too.

There is a reason why race cars have 4 wheels and not 3...

G.

PS: here is a pic of A-3 before it crashed... it was FAST... first gear was 52 mph... and still had plenty of room to go... Other pic is A-1 Quad and A-2 riding together.
 

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Wassup bud!, long time no post here.. you've been busy!
I rarely have time to make progress on my project. The shell is off the trike at the moment but I got it running.

Do you know what caused the rear wheel lockup?

Also, do you sell kits, and/or could you share your rear frame/differential/suspension design and/or a parts list so that I might consider upgrading my trike as well, or possibly ordering another used KMX and upgrading it to a quad?

How much does your quad weigh?

My issue with a quad is legal definition. In much of the US, even without a motor, it would be considered a car, neighboring Illinois being one such state.

I'm well aware of why race cars have 4 wheels instead of 3. I prefer 4 to 3, in fact. 3 is what allows me to remain legally a "bicycle".

I've also considered making a high-performance quad out of a Quattrovelo, using two Grin all-axle motors up front and an Astroflight mid drive in the rear.
 
I rarely have time to make progress on my project. The shell is off the trike at the moment but I got it running.

Do you know what caused the rear wheel lockup?

Also, do you sell kits, and/or could you share your rear frame/differential/suspension design and/or a parts list so that I might consider upgrading my trike as well, or possibly ordering another used KMX and upgrading it to a quad?

How much does your quad weigh?

My issue with a quad is legal definition. In much of the US, even without a motor, it would be considered a car, neighboring Illinois being one such state.

I'm well aware of why race cars have 4 wheels instead of 3. I prefer 4 to 3, in fact. 3 is what allows me to remain legally a "bicycle".

I've also considered making a high-performance quad out of a Quattrovelo, using two Grin all-axle motors up front and an Astroflight mid drive in the rear.

Hi bud!! Good to hear from ya! Hope you are doing well!!

Sorry to hear about the lack of time to make progress... I know the feeling very well... this past few years the lack of $$$ has been rather noticeable too...

Yes, a bump that caused the chain to derail into the spoke-cassette gap and seized the rear wheel. It wasn't fun, another reason why I would never ever drive a trike with a chain drive that can get in there and lock up your rear wheel. And it wasn't the 1st time, b/c it happened when I first put together A-3 back in 2018ish... but I was only doing 3 mph so it wasn't a big deal... until it wasn't.

LOL... I was being sarcastic about the 3 wheels, man... I know YOU know!! its just that text sucks... HAHA..

I haven't weighted A-1 so far, but it isn't much heavier than A-2, give it a few extra lbs... the rear assembly isn't that heavy.

I couldn't find anything in the WI definitions about a quadcycle being considered a car, but that is why I haven't bother with a fairing on the quad yet. I want it all exposed so its certainly and unmistakably a bicycle and ppl see me pedaling it...

The Milan SL I knew you wanted one really bad... congrats on getting it... and motorizing it... woohoo.

The quad is certainly less efficient than the trike, probably b/c its running low pressure tires and one extra, and smaller diameter, wheel than its trike form... but its rock solid I can drive it on snow, icy conditions... it handles winder a lot better than it did as a trike... you can get on the throttle much easier.

Sent you a PM.

G.
 
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Yes, a bump that caused the chain to derail into the spoke-cassette gap and seized the rear wheel. It wasn't fun, another reason why I would never ever drive a trike with a chain drive that can get in there and lock up your rear wheel.
I had something similar happen on an early version of Crazybike2 2WD Semi-Recumbent Recycled-Parts Cargo eBike: "CrazyBike2" I don't know where the pictures of the damage went but it was pretty bad. :/
 
I had something similar happen on an early version of Crazybike2 2WD Semi-Recumbent Recycled-Parts Cargo eBike: "CrazyBike2" I don't know where the pictures of the damage went but it was pretty bad. :/

Ouch... Amber... I am sorry to hear. Hopefully you weren't badly hurt... I had bruises on my left ribs (no fracture) and the knee that was high scraped over the pavement, I was wearing long pants but still road rash them pretty good...
 
thankfully i didn't crash, just skidded to a stop in the middle of traffic.... but it took around an hour (more? was like 16 years ago so don't remember for sure) to retrue the bent up wheel and other stuff enough to be able to even roll the bike, much less pedal home.

(nowadays I couldn't pedal it fast enough to keep it balanced, which is why I use a trike now so I can go as slow as needed and stop whenever i can't keep going, if something ever went that badly wrong).
 
Yes, a bump that caused the chain to derail into the spoke-cassette gap and seized the rear wheel. It wasn't fun, another reason why I would never ever drive a trike with a chain drive that can get in there and lock up your rear wheel. And it wasn't the 1st time, b/c it happened when I first put together A-3 back in 2018ish... but I was only doing 3 mph so it wasn't a big deal... until it wasn't.

G.
Makes me want to fabricate a spacer that goes between the freewheel and the hubmotor so that this can never happen! Fortunately for me, the gap between the freewheel and hub is wide enough that the chain has never gotten caught.
 
My issue with a quad is legal definition. In much of the US, even without a motor, it would be considered a car, neighboring Illinois being one such state.
Similar nonsense here in Spud land, but actually worse. Although Statutes here are somewhat vague, you almost need to be disabled to legally pedal even three wheels on public roadways. E-assist bicycles, by Statute definition here, clearly states "two (2) tandem wheels". There's 3 wheel "Moped" class, but it requires a valid driver's license.
 
Similar nonsense here in Spud land, but actually worse. Although Statutes here are somewhat vague, you almost need to be disabled to legally pedal even three wheels on public roadways. E-assist bicycles, by Statute definition here, clearly states "two (2) tandem wheels". There's 3 wheel "Moped" class, but it requires a valid driver's license.
Hmm, interesting... I assume you mean Delaware?
 
Makes me want to fabricate a spacer that goes between the freewheel and the hubmotor so that this can never happen! Fortunately for me, the gap between the freewheel and hub is wide enough that the chain has never gotten caught.
Well, the chain getting in the way is one way it can lock up, the caliper can fail and lock up, rotor disc can crack and seize the wheel... lock up, the wheel can go flat and you are in a scary world... as I've found out a couple of times... etc.. maybe its me that I am paranoid now about third wheel locking... but trust me, once you've ridden a quad, there is no going back to anything less... even without rear suspension. The sense of stability and being "planted" on the ground is uncanny... it reminds me of a go-kart...

I know ToeCutter has a KMX, but I wouldn't recommend converting aluminum frames to quads without some rigidity mods, since the extra torque/torsion from the rear axle when going over uneven surfaces can potentially fatigue and crack the aluminum frame after a while. Again, the KMX trike frames are all good old steel, easy to repair, super easy to weld... etc... and much springier than AL for a torsion bar and will not fatigue so long you don't bend the thing 45 degrees. :)

Another issue I had with A-1 when it was a trike is that running a shunt-controller 6.5kw mid-drive the frame was twisted counter-clockwise, so the rear wheel had a like 7 degree camber... 6kW on it and doing 60mph runs took its tool on the frame... I had to straighten in back... that is another issue you won't have in a quad + a high power middrive, the axle prevents the torque twisting the rear end when applying max throttle.

As for laws and regulations, I am not encouraging anyone to break them. :)

Now, if was going to "bend the laws" I would like to make sure I am not caught in a 30kW quadcycle that looks like an LMP prototype that runs the 0-60 dash in 2.3 seconds flat.... so just be sensible if you turn it into a quad...

Personally, now I run my 3kW quad in controller mode #1, which tops out, in 1st gear, at around 25 mph on a flat road. I know very well A-1 can push well over 60 mph on engine map #3 and a couple of gears up... but 25mph is plenty fast for a 4 mile commute; and then again, once you've been airborne performing barrel rolls on a non-airborne capable vehicle, you really develop a heightened sense of "I can die" here...

:D

G.
 
They make spoke protectors taht would probably do the job; I've p[ulled them off junk bike wheels now and then. (but many here are sunrotted and disintegrate).
Not sure if I am willing to play chicken again with my life with some "protectors" after what I went through man... hahaha :D but again... YMMV... :D

Oh, I forgot to mention, before going airborne, the side of my helmet smashed the road pretty good before flipping out...

So, act accordingly... pics of the helmet...
 

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So sorry to read about your mishap... and glad you're apparently ok and still riding.


If you are aware of the following, I apologize if it's old news. I make mention for others potentially following.

While I generally agree that 4 wheels usually trumps 3 wheels for anti-roll improvement, However, 3 wheels has frequently been proven safe when the builder optimizes all the geometry and handling parameters for the intended speeds,... and, adheres to known riding limitations. I been riding 3-wheels for well over 2 decades now, and no loss of paint or skin... so far.

Optimum CoM location for trikes (both vertical and longitudinal) is very critical, (2/3 gross front axle, 1/3 gross rear axle, on tads - and 1/3 front, 2/3 rear on deltas). CoM height should be no more than half (1/2) the 2-wheel axle track width at gross (i.e. 30" track width allows 15" maximum CoM height).

It's important to remember that both human powered Tadpoles & Deltas were never originally intended or designed to be motorized, nor expected to exceed speeds much greater than about 18-20 MPH. Therefore, increasing top speeds on either platform conversion, demands very careful consideration & planning.

As speed increases, so too does steering sensitivity - more so on Tads because the wheelbase is usually shorter, minimum caster is factory set, and the CoM is further forward.
  1. At a minimum, I would increase the wheelbase at least 20-40%. This change will noticeably reduce steering sensitivity at elevated speeds, and, allow slightly more tolerance in longitudinal CoM placement (on Tads, this will also help to prevent rear wheel lifting during hard braking).
  2. On Tads, I would also add a degree or 2 of caster,... and perhaps 1/8-1/4" tow-in if rig has any tendency to "hunt" at speed.
  3. Converting Tadpoles to quads beckons its own set of requirements - just simply adding a rear axle I would discourage, unless of course, you either add ballast to the rear, or move the pilot's seat rearward to achieve a somewhat 50f/50r weight distribution.


Indeed....

View attachment 368504
No disrespect, but nothing you say, nor anyone else for that matter, will convince me that three wheels is or can be "optimal" after what I've lived... you are free to do whatever you want, but logic will make zero difference when your head smashes the side of the road, at 25mph, and you go airborne on an spectacular barrel roll to crash land and drag the top of your helmet until you come to a screeching stop while dragging your head, bruised, sore neck and bleeding on your knee with a road rash wound the size of a golf ball.

It is a miracle I am alive... and I am not going to push my luck on three wheels ever again... not for anything that rides >10mph.

G.
 
The rear suspension extended my wheelbase out. The "dork disc" would add another layer of protection against catastrophic failure, but having a single rear wheel still means such failure can always occur in some way.

With the single Leafbike 3T in the rear, running 46.8V and 250A phase current with a 10kW limit, this thing beat a V6 Dodge Charger in a stop light drag race to about 35 mph. It's also done lots of donuts in parking lots and intersections without tipping over. Legality only matters if the police can catch it, and/or locate you/it later!

I want to build a quad now, rather than turn my existing KMX into one. Thinking of maybe a Steintrikes Mad Max with Grin All-Axle 3T hub motors at 6 kW each up front, and a 20 kW middrive in the rear, set up with rack and pinion steering. The body would be covered in roughly 400-600W of solar panels. Another possibility is to buy a Velion and do the same, but I currently do not have space for another project, or time to work on it.
 
To your point on converting to a quad... I've moved the seat backwards by several inches, and I've cut the front pedal tube to bring the pedals closer and almost to the edge of the front wheels... so I sit pretty much in the dead center of the quad. I've also added weight to the back with the 16ah 20s battery pack...
 
I want to build a quad now, rather than turn my existing KMX into one. Thinking of maybe a Steintrikes Mad Max with Grin All-Axle 3T hub motors at 6 kW each up front, and a 20 kW middrive in the rear, set up with rack and pinion steering. The body would be covered in roughly 400-600W of solar panels. Another possibility is to buy a Velion and do the same, but I currently do not have space for another project, or time to work on it.
Well, that sounds expensive $$$... and all the parts for each quad conversions where a bit over the 300 bucks mark... hard to beat that price. The conversion took, all in all, about 4 hours to execute, and the securing of the rear assembly to the Y rear fork of the KMX frame being where most of the time was spent... the rest was pretty much tightening bolts.

As for the donuts, sure, doing donuts on a flat surface is fine... A-1 did donuts just fine during its heyday as a trike... but being sideways without the ability to release the rear wheel to control the drift, while going downhill at 25+ mph on an off-camber right hand turn is another... it WILL flip, either the CoM gets you or the front tire buckles as another member here also stated. (which also buckled on my case)
 
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Well, that sounds expensive $$$... and all the parts for each quad conversions where a bit over the 300 bucks mark... hard to beat that price. The conversion took, all in all, about 4 hours to execute, and the securing of the rear assembly to the Y rear fork of the KMX frame being where most of the time was spent... the rest was pretty much tightening bolts.

As for the donuts, sure, doing donuts on a flat surface is fine... A-1 did donuts just fine during its heyday as a trike... but being sideways without the ability to release the rear wheel to control the drift, while going downhill at 25+ mph on an off-camber right hand turn is another... it WILL flip, either the CoM gets you or the front tire buckles as another member here also stated. (which also buckled on my case)
Understood. I've had the Milan up to 89 mph downhill!
 
No disrespect, but nothing you say, nor anyone else for that matter, will convince me that three wheels is or can be "optimal" after what I've lived... you are free to do whatever you want, but logic will make zero difference when your head smashes the side of the road, at 25mph, and you go airborne on an spectacular barrel roll to crash land and drag the top of your helmet until you come to a screeching stop while dragging your head, bruised, sore neck and bleeding on your knee with a road rash wound the size of a golf ball.

It is a miracle I am alive... and I am not going to push my luck on three wheels ever again... not for anything that rides >10mph.

G.
After your experience this is a moot point (for you) :), but 2 words:
Tilting/Leaning Trike.


Now you have:
  • Legal..? (The main reason and lower rolling resistance)
  • High Ride Height is no longer a stability issue = more visible and safer.
  • The equivalent of a 2 wheeler, with around twice the braking capability in a Tadpole. (ONLY)
  • With a Tilt Lock for stopping and low speeds the design can be Feet Up = enclosed = aero and dry/warm.

The challenge is a (complex) design that is both pedal-able and lean-able.
There are some on the net, but no time for searching and linking atm.

It seems to me that had one or both rear wheels on a quad locked up the end result may well have been similar??
So a design that does NOT lock up ANY wheel is actually what's important here???
 
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After your experience this is a moot point (for you) :), but 2 words:
Tilting/Leaning Trike.


Now you have:
  • Legal..? (The main reason and lower rolling resistance)
  • High Ride Height is no longer a stability issue = more visible and safer.
  • The equivalent of a 2 wheeler, with around twice the braking capability in a Tadpole. (ONLY)
  • With a Tilt Lock for stopping and low speeds the design can be Feet Up = enclosed = aero and dry/warm.

The challenge is a (complex) design that is both pedal-able and lean-able.
There are some on the net, but no time for searching and linking atm.

It seems to me that had one or both rear wheels on a quad locked up the end result may well have been similar??
So a design that does NOT lock up ANY wheel is actually what's important here???

A leaning trike would've not helped me when the rear wheel locked up. My steering input wasn't that much when it went sideways, faster than I could react, and the snap oversteering wasn't caused due to too much steering input. Also, in cars, you control oversteering by counter steering and throttle, if you countersteer while riding a tiling trike, you'll probably do two barrel rolls when the thing goes sideways.... I hope your luck never runs out like mine did. I lost a significant investment of time and money when A-3 wrecked.

As for your points:

-Now I have a vehicle that is far more stable than anything on three wheels. Succeeded on what I set out to achieve.

-No issues with legal that I am aware of where I live.

-I no longer care that much about efficiency, since the quad is still 100 times more efficient than any road going vehicle when using motor, and when I pedal it its infinitely more efficient than that. What I really care about is not getting injured, plus I can ride this thing in snow/icy conditions much safer than anything with three wheels. I think aero is far more important than having some extra rolling resistance due to a 4th wheel as I've measured a long time ago.

-The Quad runs even lower than the trike did, with x4 20" rims vs. x2 20" fronts and x1 26" rear.

-The rear quad assembly made the frame about 6 inches longer wheelbase as well.

Nope, locking the rear wheels on A-1 quad, while turning, on the same downhill at the same speed that caused A-3 trike to wreck, A-1 quad didn't go sideways, therefore it didn't flip, and didn't even feel light on the other side, and the outer tire didn't buckle at all. Instead, as soon the rear wheels locked up, the quad reduced speed drastically, and the yaw rate went down as well. That and the chances of the chain ever locking up the rear wheel(s) is now zero: as there is no physical way to lock up the rear differential even if the chain wrapped around it like a pretzel. The wheel spokes are also covered, so no chance of anything getting stuck in there either.

The fact I can take tight roundabouts at, at least, twice the speed of what I took them on the trikes is good enough for me. I don't drive this thing at 60mph, I rarely go above 30mph now... And the quad generates so much cornering lateral G-force that if I wasn't clipped when taking tight turns I would probably get ejected off the dang thing...

My humble advice is to go Quad, or remain on 2 wheels. Any trike, especially a delta trike, going at any decent speed, its just an accident waiting to happen. You might get lucky, but your luck could ran out (like mine did), and I simply don't want to play again and see... basically, I don't want to "Find Out" anymore.

A delta trike locking up its front wheel while going 35 mph on a downhill turn sounds like a perfect way to end up on assisted life support... seriously... I hope you don't drive that delta trike of yours at anything above 15mph... or motorize it to reach 65 mph like A-1 and A-3 were more than capable of achieving... math or the "Ironclad trike equation by Logic11" won't matter much when you are paralyzed from your neck down...
 
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Any trike, especially a delta trike, going at any decent speed, its just an accident waiting to happen. You might get lucky, but your luck could ran out (like mine did),....
"Luck" (or if you prefer, unlucky), is reserved for fools & idiots... I personally prefer 'cause & effect.
I have daughter your age Mr. Gman, and ya know what i've repeatedly told her?... If dear ol' dad's luck ever expires, it's a safe bet he either frocked up, or his ticker gave up. Luck will have absolutely nothing to do with it.

Interesting observation... www.youtube.com/watch?v=vqdeZMUZo9k

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1744288086755.png

A delta trike locking up its front wheel while going 35 mph on a downhill turn sounds like a perfect way to end up on assisted life support... seriously... I hope you don't drive that delta trike of yours at anything above 15mph... or motorize it to reach 65 mph like A-1 and A-3 were more than capable of achieving... math or the "Ironclad trike equation by Logic11" won't matter much when you are paralyzed from your neck down...
Funny shit. Sorry, I bore easily reading fairy tails.

.... the side of my helmet smashed the road pretty good before flipping out...
Ok, I get the picture now.

@Toecutter: My apologies, I'm done here.
 
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