Rafe Husain and the 40c3: Q & A with an Ebike Transportation Innovator
Imagine you live in Riverside County and work in Orange County, or LA. But you want to use bike and public transportation. Clearly there’s a problem. So you try as best you can. You buy an eBike, but it’s as heavy as a rhino. So you think about how to solve your own little problem. And along the way you come up with something.
That’s the story of Rafe Husain, inventor of the 40c3, and founder of Calibike. Its a super-lightweight, fast ebike complete with anti-theft technology built in. Not only does the bike have an alarm and a GPS tracker, it is also password protected.
Now, before you get started on the word “bike”, look at the word “innovator”. The transportation technology we talk about today was started by some guy or gal with an idea and the will to execute a little bit more.
Have YOU come up with a way to combine biking, batteries and ease of riding? If so, click on. If not, read on.
We took the opportunity to talk with Rafe and his hybrid bike in a fun and freewheeling Q & A.
Q: How did you come up with the idea for the 40c3? What was the unfilled need that you saw?
Traffic in LA/Orange County is a mess. For me it was hours of stressful driving to the point you need another hour at work to de-stress. Then I developed bilateral Blepharospasm, which meant it is better for me to avoid driving. So I ride my bike 3.5 miles from home to train station. Once on the train, I relax, check email and surf the net–like everyone else. I then ride my bike from the train to work, about 7 miles.
Current ebikes are weight hogs weighing from 55 to 90 lbs +. I had a Currie bike that weighed 82 lbs. I could barely lift it on the train. It was un-pedalable if the power was out. I just didn’t like it.
Q: Why do you call them “hogs”?
If an ebike is so heavy that you can’t pedal it without motor assist I refer to it as a hog. If it’s too heavy to lift up stairs, or onto a bus and train, it’s a hog as well. A lot of ebikes out there weigh 55 lb. or more. That’s heavy. If you look for something lighter, you run into a problem with the motor not being powerful enough. There are some bikes which weigh less than 55 pounds. But their motors generate only 250 watts, which isn’t enough power.
Q: Is the 403c a hog? Why not?
I started with a lightweight semi Fixie road bike (7 spd, 8kg) to which I added low-weight, high performance batteries and a low-weight geared hub motor. One point I would like to make about the 40c3 is that due to the huge chain ring the bike makes me work out while riding. Secondly, and this is very hard to believe, but due to the speed at which I am traveling I don’t build up a sweat. I get to work wearing my work clothes exercised but with nary a drop of sweat. In fact some days my legs hurt for 2 hours in the morning, yet no sweat.
I thought it weird as well. I did a little research and found that a study at the University of Oklahoma confirmed my sanity. The article about the study is called “Same Great Workout, Just Faster and More Fun.”
Q: Can you describe the improvement in ease of use?
Some of my friends who rode the 40c3 said that going up hills and inclines was so easy that it was simply shocking. They couldn’t believe something that still felt like a bike could do that.
Q: How long has it taken you to get from idea to current state?
It wasn’t one trick. Like most things, it was a bunch of little iterations and improvements over 3 years.
Revision 0, May 2010: I started with a Currie ebike with lead acid batteries. it weighed around 85 lbs and slower than most road bikes. I couldn’t stay with road bikers, even with electric assist.
Revision 1, July 2010: I bought a kit for an electric motor, a single speed road bike and after some work came up with my own electric bike. My first version was faster (27 mph) but still heavy as it used lead acid batteries. Next I tried to build my own equivalent of ebike 18650 batteries but without a battery management system. That too was too unreliable, so I finally bit the bullet and ordered a li-ion pack. I also changed the front chain ring to a 60 tooth sprocket with a 16 tooth sprocket in the rear. This configuration got me to 35 mph. However, I couldn’t get the bike lighter than 52 pounds.
Revision 2, December 2011: I ordered a new motor with reduced weight and reduced power. I mated that to a single speed road bike and li-ion battery pack. this build allowed me to reduce the weight to 44 lbs but speed went down to 28 mph max.
Revision 3, December 2013: I went at it from a different direction, and found myself making a breakthrough. I ordered a high rpm 36 volt motor that I over-volted to 48. I decided to build a bike frame from scratch, taking the time to weigh each part. Once the new frame was complete, I merged it with 60-tooth front chain ring and 11-tooth rear chain ring, giving me a 5.5 to 1 ratio. I then added a 48 volt, 15 amp li-ion battery with a BMS using lightweight 18650 cells (same cell type as Tesla although my batteries are generic 18650s). Next I added a 12 fet motor controller using 3077 FETs. The 3077 Fets have very low on resistance (rds on) so very little heat buildup in controller. The benefit meant the controller wouldn’t fail due to overheating. The motor itself is a geared hub motor and is 85% efficient and doesnt overheat. This combination was the magic which got me to a 40 lb. total weight, 40 mph top speed and a range of 40 miles. No one trick but a bunch of little iterations and improvements over 3 years
Q: Any stories to tell on the ups and downs of creating a new product?
My bike friends still dont believe that I can get exercise on my ebike. They think it is cheating. In fact they wouldn’t believe my speeds till I put my GPS log as closed caption in my videos.
I wanted a current sensor multimeter, but I didn’t want to send 48 volts through it. Plus I needed something that could track history. So I developed my own tool called Calisensor which can sense current in a passive way. The Calisensor is a great tool for any EV engineer. It can log current using a non invasive hall sensor to measure up to 100A without having to put a current sensor in series with high voltage/high current wires. It’s a great innovation, one that I’m trying to get the word out about as well.
Q: What is the funniest thing to happen along the way?
Put one ride on Strava instantly was crowned king of that stretch. Then the other bikers complained about the 40 mph+ and they demoted me!
Q: When was it that you knew you had “something”?
When my car was in service for a week and I realized I could live with out it just fine. Then I sold the car and lived of my ebike.
FYI, my wife has minivan so I do have a vehicle if I need it.
Q: Looking at one of your videos, seeing your shadow, it does look like a very smooth ride. Describe how the 40c3 rides differently from an eBike, or a moped. What elements combine to make the speed look so smooth?
With the push of a switch it can go from motorbike to moped to ebike to bike. The rider chooses the proper mode.
It rides like a road bike on roadways so the experience is pretty smooth. It’s not like a moped, which is very heavy. The 40c3 can be pedalled manually. Legally, California law defines a moped as having less than 750 watts which the 40C does. Additionally the law says a moped must go less than 30 mph which it does in a setting for US compliance.
The 40c3 also has 4 settings:
- All compliant (non motorized bike mode),
- EU compliant mode
- US compliant mode.
- Non-compliant mode.
Non-compliant is like porsche in 5th gear.
Q: Based on your hackster.io profile, this looks like a recipe that most anyone with better mechanical skills could build. Just buy pieces of your kit and build a similar model with a cycle of their own choosing. Is this where you see your product going? Why or why not?
I am debating selling the whole thing or just as a kit which people build. Basically I am not sure how many people would be interested in a ebike that can be motorcycle, moped, ebike and bike with the flick of a switch.
Q: This sounds like a pretty big decision. Can you share some of your thinking behind each decision point? Benefits and disadvantages of each? What are the differing directions your company takes based on that decision?
If there is enough interest I would definitely sell it as a complete ready to go system. I would like to have local agents who do final assembly and turn over fully tested 40c3 to customers.
Q: What’s the recharge time? How many miles on a full charge? How many miles at average v. high speeds?
Recharge time is 3.5 to 4 hrs on a fully depleted battery. The range is 40 miles at 20 mph drawing power from the motor only. To maximize range on the 40c3, basically run it in EU compliant mode.
Q: I like the alarm/GPS locator/security aspect, what made you think of it?
It’s an expensive bike, and I’d hate to see it stolen. I am a cell phone engineer and my familiarity with GPS trackers made adding it a no-brainer.
Q: Locking the battery to a cellphone is ingenious as well. If the battery node is locked to a cellphone, tell us how a 40c3 owner can override in case their phone is lost or stolen?
When you buy a 40c3, you’ll receive a battery code. Using this code, the owner node locks their phone to the battery via Bluetooth. If phone is lost, the owner can retrieve the code from their email. Then they simply re node lock the new phone with the battery.
Q: What if I lose my phone while on a ride? If my bike is locked, and I accidentally drop my phone down a grate, describe my options.
You get a new phone and you node lock it. It will need orginal battery password which was emailed to you. You punch it in and your new phone gets node locked to battery. You can node lock multiple phones to same battery or have only one.
I am also thinking of additional smart battery features like a semi-password and retarded password. A semi-password will let you ride for 4 hours and then expire so you can lend bike to friends.
A retarded password will let you ride at 20% power to limp home in emergency. This could be set as an easy to remember password that you could enter from any cell. The retarded password would allow you to give someone a way to get home or someplace in a pinch.
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