Completed: Custom E-Bike Cargo Commuter Bike

SimiGuy

1 mW
Joined
Nov 28, 2015
Messages
16
Location
Southern California
After almost 4 years of fun, I finally finished my first e-bike. I call it the "Mastodon". Uses a Cylone 3000W motor with a 52V, 21 Ah battery (EM3EV - those guys rock by the way - highly reccomend!). Bike is working well so far - almost have 300 miles on it and the only failure so far was the stock front chaining freewheel. I bought the top of the line Sick Bike Parts Freewheel to replace it and has been working great since. Bike also features a custom center steer hub up front and utilizes a 3 speed Sturmey Archer IGH in the rear. I learned a lot and realized that it is way harder to build an e-bike than a regular bike!
 

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Thanks. Here are some CAD drawings & a few pics but it's hard too see because the details don't show up too well with the black hub.
 

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Impressive hub-center steering system; very nice looking work.

How does the weight compare to a fork? What effective head angle did you use?
 
Damn, did you build that at work or is that your HOME workshop? I've lost interest in the junk I can build at home, I want to do the stuff YOU are doing, but I need YOUR garage, not mine.

I think Chalo wants to hear how you know the fork will hold up under loads. I'm wondering how it handles with one.
 
Thanks for all the compliments.

Chalo, the effective head tube angle would be 68 degrees. Not sure about the weight after all is said and done. I mainly did it because I wanted this particular configuration of a large cargo area over the front wheel which makes it hard to use a fork and wanted to try the center steer hub thing. Not many bikes out there with this layout - I usually try to build stuff that's different and that I couldn't just buy otherwise. I have to say that I was impressed by how stable this design came out. I can ride this thing no hands and when going down a hill at 40 MPH - plus, it fells rock solid.

Dauntless, about the shop, yeah, I am very fortunate to work at a place where we have some awesome machine tools (including CNC mills) that are available to use after hours for personal projects. So no, that isn't my garage (I wish!) but pretty awesome work perk... one of the big reasons I work where I work...

Thank again!
 

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I chose 68 degrees for the head angle on my front loading cargo bike, too. I made a long steer tube fork from an existing BMX fork, so the offset dimension isn't ideal for the head angle. But it has generally good docile handling characteristics, and I'll replace the fork sooner or later to try a longer offset.

I built mine like a cycle truck, with the load forward of the steering axis. I sloped the load platform because it was originally intended to carry a passenger seat for an adult, and I wanted the passenger to stay against the backrest with feet up out of harm's way.

View attachment 1


In imagining how I'd tackle your frame's layout without access to 3 axis CNC milling, I was thinking I'd use a turntable bearing, and attach one side to a plate on the bottom of the cargo platform and the other side to a plate on top of the fork legs. Pin the plates through the middle with a bolt, thrust bearing and locknut.

Yours looks cooler than that solution would, and probably has higher load capacity per weight because it's not cantilevered from the frame.
 
OMG SimiGuy, That is so awesome! If thats your first e-bike, then I can't imagine what the second one will be like! :shock:

Your attention to form and function is exquisite, and you have gone to the great beyond with your front hub steering.
Truly a masterpiece, I would call it the "Master-don"!
Every pice and part is so well designed and thought out. The 'look' flows like water,..a sign of perfection.

Congratulations on a spectacular finish after four years of thought and effort. It belongs in an art display. I would be afraid
to actually use it for anything!

How is the Sturmey IGH working out, and what kind of speed and distance do you get? :)
 
Chalo, yeah you did pretty well with a difficult situation. All that weight up front with the CG of the payload in front of the wheel contact patch is tough. That was why I went with the hub center steer, so I could get the wheel further forward and maintain a good weight distribution and use a large diameter (24" ) front wheel - which meant no room for a conventional fork. I've had a grown adult on the cargo bed (230 lbs) and felt like the bike was still handling well. I also wanted to be able to sit on the front platform and not have the bike topple over when parked - kind of use it as a chair. Your idea for steering should work. The beauty is you could use a standard wheel with regular hub. My solution is definitely a "one-off" that would be too expensive to ever put into production. CNC'ing definitely opens up the possibilities.

Wow, APL, thanks for the kind words - glad you like the design! I like that, "Master-don" ha! Thanks, I've built 5 bikes before this one but they were all non-electric - so I did have some practice. However, the electric thing added considerable build time - didn't realize how much more complexity that adds to a bicycle and how much stuff I had to figure out & learn!

Yeah, I'm hoping the Sturmey IGH works out. I guess time will tell. So far I have about 300 miles on the bike and it's been doing well although I have noticed a few gear "slips" here and there. I usually keep it in 2nd gear (which I understand is direct drive) when accelerating from a stop or going up medium slope hills. So I try not to push too many watts through the 1st & 3rd gears if I can help it. I typically cruise at about 21 mph in 3rd gear on flat which is a nice comfortable pedal cadence for me - this scenario typically uses about 450 Watts on my commute. This is with the standard Cyclone kit chainrings and my 29" rear wheel (I forget the #teeth on the rear cog). One thing to watch out for on the IGH hubs is that they want to loosen your rear axle bolts. I found this out the other day - I rode with the rear axle nuts completely loose for like 3 days... kept checking my rear disk because it started rubbing then I finally realized the whole rear wheel was loose! Kinda scary! Lots of locktite & torque on those nuts now! I rarely have the need for the lowest, 1st gear. Wish there was a bullet proof 2 speed hub out there somewhere!

The bike tops out at about 32 MPH on flat but I can't keep up with the pedals at that speed. I would say an average range in my hilly environment is about 50 miles - but I always pedal at a nice comfortable pace & effort. I haven't just ridden the bike motorcycle style... no pedaling. When I rode it at the beach at pretty low speed, I went about 40 miles and only used 60% of the battery - so at that slow pace I could have gone at least 60 miles (this was on the Marvin Braude Bike Trail on the LA beaches).
 
Very nicely done.

I would like to do something similar but a long tail cargo bike instead of your super cool hub steering setup.

I want to use a Sturmey Archer 3 speed and a Cyclone mid-drive like you are but also steal a bunch of ideas from the Cycle Stoker setup to do a strain gauge based pedal assist and with a two speed crank to try and give it a bit more top end and a granny gear low enough to limp home on.

That's my first question, can you tell me your exact gearing?

Second, which controller did you use and if you monitored your power, how high was your peak power, how much power was an average 0-15 or 0-20 mph start that was not full throttle but reasonably quick? If you have any numbers for power at speed, I would love those too.

I want something that has 40 mph capability when I really need it (trying to avoid getting hit by a car), 25-30 mph cruise, maybe up to 35 mph if it works out and enough torque in low gear that starting from a stop on a slight incline is easy with pedal assist, even when total bike + rider + cargo weight approaches 500 lbs (probably using an Xtracycle style side car to carry about 200 lbs of that total).

It's a lot but if I get the details right, including a custom frame, I think I can pull it off.

I've made a custom frame before and have a lot of other design and fabrication experience under my belt so I think I know how to approach this challenge.

Hopefully I'll pull it off well enough that I could park it next to your bike without feeling too embarrassed.
 
Smoke said:
I want something that has 40 mph capability when I really need it (trying to avoid getting hit by a car), 25-30 mph cruise, maybe up to 35 mph if it works out and enough torque in low gear that starting from a stop on a slight incline is easy with pedal assist, even when total bike + rider + cargo weight approaches 500 lbs (probably using an Xtracycle style side car to carry about 200 lbs of that total).
At those speeds with that load, you are going to want as large a diameter wheel as you can get, with as big a tire as you can get, and preferably full suspension, or at least suspension on the cargo end of things.

If you don't, then antyhing other than perfectly smooth roads is likely to do some damage to your wheel, if not outright destroy it or cause a crash, depending on conditions.

I've got two rear wheels on SB Cruiser for the cargo area, and it's total weight is probably about the same as your goal, and I've damaged rims on holes at only 20MPH (and less) with no suspension, 16" Shinko SR714 2.5" tires on ex-Zero-MC rims. Didn't break any spokes, but on the worst one the wheel as a whole was damged enough to be untruable, though it's still rideable, if wobbly, and the tire stays on the bent rim.

Don't want to imagine what that impact would''ve been like at 30 or 40MPH--it took a fair bit of velocity off my speed at that moment, and converted that into energy focused on the impact point of the wheel and edge of hole.

Same thing happened with a rain-covered invisible hole on my smaller longtail CrazyBike2 with the same rear wheel type (but a bicycle tire).

On SBC, I've also broken two different motors' axles from impacts under load (>500lbs total, probably 600+), and another motor's axle broken from torque testing a new controller.



Bigger diameter will go over/thru holes smaller ones won't, and ride smoother under the same conditions the smaller doesn't.


The other thing you need is great traction (and big contact patches) for your brakes, which will have to be really good, to be able to stop you from the highest speeds you will be reaching, while fully loaded at max weight.



FWIW, CB2 uses around 80A with 2WD to reach 20MPH in about 4 seconds at probably about 400lbs total. SB Cruiser uses around 120A with 2WD with heftier motors to do the same thing at 500lbs. IIRC another 40A+ on top of that gets me about a second less, using the SFOC5 controller from Incememed under testing, on the right wheel, and a modded generic on the left.
 
I don't intend to travel at high speeds with a big load. Either or, not both.

My previous bikes I have badly flat spotted rear wheels but my fronts are always fine (700*23c).

I figure a long tail will move some load to the front wheel where I'll have a suspension fork and MTB style wheel with disk brakes.

At the rear, I intend to use a suspension seat post to soften the blow when I hit a pothole. I plan to use a 20" heavy duty BMX style rim to give it some air spring at the contact patch.

I don't want to go any larger because I think the smaller wheel is going to make my gear ratios work better, keep the cargo deck low and I want a spare wheel with IGH for the side car so I can swap if I destroy the gears on a ride. I think the stowed sidecar will look a little less goofy with a 20" wheel than 26".

I want a multi-purpose commuter, not something that hauls 500 lbs over potholes at 40 mph going up hill.

Most of the time it should be doing stop and go on flat land with relatively smooth pavement but I don't want to design a new bike the moment I want to do more than that so I am defining the edge of the envelope, not the center.
 
Hey Smoke, sorry for not replying sooner -it has been a while since I've been to the Sphere...

My gearing is a 20 Tooth sprocket on the 3 speed Sturmey on the rear and the 44 tooth chainrings at the cranks that come stock with the Cyclone 3000W kit. My rear wheel is also a 29 inch - so pretty big diameter

I am still using the stock 40A controller that comes with the Cyclone kit.

For an average 0-15 gentle start I see about 1000 Watts peak with me pedaling also. For a quick start without pedaling I've seen about 2000 to 2200 Watts peak. When cruising at about 21 mph on flat I use 450 to 500 Watts while also pedaling at a comfortable rate.

I live on a steep hill (not sure what grade) and can do about 16 mph up that hill using about 1800 Watts while adding some non strenuous pedaling. Hope some of this helps. Good luck with your project.
 
Thanks, that's a great reference point for me.

Hopefully I'll get my gearing pretty close to that.
 
On other forums (on other subjects), this would definitely be considered an "Ultimate" build. Fantastic work, and stylish as well. I'm interested in how you fabricated the battery/motor cover. That make this bike not only an ultimate, but a stealth build; people would be so impressed by the workmanship, that they might miss that it's an e-bike.

There's a lot to be said about stylizing the way the battery and motor integrate with the rest of the bike, rather than looking like the parts are just bolted on. While a lot of the factory bikes are attempting to integrate the battery into the frame, it's still pretty obvious, but I've seen others where the pack is more or less bolted on, but with some creativity, like having the overall paint scheme flow up through the battery, make it all fit together and integrate even more nicely, visually.

While the mechanical and design components are superb, it's really how it all flows from a style perspective that makes your bike something that ANYONE can appreciate. :bigthumb:
 
E-HP, thank you for the positive comments on my design. Yeah, it always bothered me how most electric bikes don't have a good flow to the electrical components - always a big battery scabbed on to the frame somewhere and motors hanging out. Glad you picked up on what I was trying to accomplish with the overall design.

I designed this whole bike in SolidWorks to a very detailed level. Once you do that all the parts fall together and fit surprisingly well. I already had the frame welded up and the motor installed at this point (the bike was ride-able). I had the motor/battery fairing modeled in SW and double checked the real world frame dimensions to the CAD model to make sure everything would still fit. I made a few adjustments in CAD and then used a CNC mill to machine out a male master plug for the fairing. This was a bit complicated because I was using a small CNC so I had to split up the fairing shape into 6 pieces and machine them individually and then assemble them back into one master plug.

I CNC'ed the master from high density urethane tooling foam. Once machined and assembled into one part, all the hand labor body work began in order to get a nice smooth surface. I used epoxy primer and paint to get a nice glossy finish and then released the whole thing with wax and PVA. Next it was time to pull a two piece mold off the male plug. I used some polyester resin /fiberglass to make the mold because a friend had lots of old resin and fiberglass mat cloth laying around. I had to create a splitter plate around the plug with aligning half-dome features so that the mold would split vertically along the plug to allow for the extraction of the final fiberglass part. So then, I first wet laid up one side of the mold, let that cure, and then the other side against the original side. Once the mold was finished I did some minor body work to make it nice and smooth on the inside and then released the mold and assembled the two mold halves together with bolts along the seam.

I then used epoxy and fiberglass cloth to wet-lay-up the removable hatch at the front upper side of the fairing. Once the hatch cured I pulled it out of the mold and sanded the edges straight and smooth. Then I put the hatch back into the mold and released the inner side of the hatch and laid up the rest of the fairing around it creating a nice overlapping lip that is a perfect match to the hatch. Once that was cured the basic fiberglass fairing was done except for the tedious trimming and fitting to the bike frame and then priming and painting with quality epoxy paint. The motor / battery fairing was actuality lot of work and took me a while to finish (body work and painting are not my best skills).

Anyway, hope this helps and thanks again for the positive feedback on the bike.
 
Your fairing reminds me of Pee Wee Herman's bike but with a better color scheme.

The more I think about making my bike the best it can be, I realize it will be my version of Pee Wee's bike.

3,000 watts of pedal assist should even make this dream sequence feasible:

[youtube]1rzg3esJaaU[/youtube]
 
Ha, yeah, I have also blown by serious road bikers just like Pee Wee on my cargo bike in work clothes and I feel kinda bad / guilty but, hey, I gotta get home or to work! I have also been drafted before...
 
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