the inspiration behind fat woody
Before going into the details of how I built it, I want to take a step back and explain why I built it. The inspiration to build a feature-rich electric motor-cruiser came to me after many vacation holidays to Florida. I absolutely love to explore and discover beautiful places. The tropical feel of Florida's Gulf Coast is just paradise. Whether it's motorcycling the Florida Keys, scooter riding around beach communities, or riding a bicycle down the beach, cruising open-air is my happy place. The sun on my face, a cool breeze... its 'relaxation' in its purest form.
fat woody is an electric motor-cruiser merging the best features of motorcycles, scooters & bicycles
Motorcycles can have some great features, like music and places to stash your stuff. While I love motorcycling in a tropical climate, I don't necessarily like wearing boots, long pants, and a helmet. I'm a board shorts and flip-flops kind of guy. I think that's why the scooters are so popular in beach communities. The cool air blowing over you as you cruise 30mph allows even 100% humidity to go completely unnoticed. But, scooters still have some limitations.
Like motorcycles, scooters are motor vehicles, and not permitted in many areas a bicycle might be. Bicycles get carte blanche access to the most beautiful riding paths in parks, around lakes, the beach, boardwalk, and even down the shoulder of a busy road. And, when was the last time you circled the block looking for a place to park your bike? I think what I like best about the biking experience is that the slow speeds let you 'stop and smell the roses' in some very picturesque areas.
what makes fat woody the coolest beach cruiser on the boardwalk?
design style was the most important element of my vision
When I first came up with the idea for the fat woody, I wanted a bicycle that looked like the vintage woody beach cruisers of the 50's. For me, these beautiful machines represent a relaxed coastal lifestyle at a time when life in America was a bit more simple. The fat woody beach cruiser would need to be a retro-reflection of the generation, artistically speaking.
It's design would present some challenges, and require some compromises. One thing I knew for sure was that I wouldn't be able to capture the true classic artistry by simply powder coating a frame and putting some wood decals on the side. It was the era of big horsepower and heavy iron, so a minimalist bicycle tube-frame was just not going work. It would need large shapely fenders, painted with bright colors and impeccably finished oak and mahogany woods.
I knew that larger balloon-type tires would perform much better in sand, but nearly every fat tire bike on the market is a mountain bike. Mountain bikes are great, but like most sport bikes, their design incorporates straight tubes. A cruiser has a relaxed curved-tube design and is more iconic of the period. Holding true to my vision, I knew an ultra-high tech mountain bike would never have the look and feel of a single speed cruiser from the era.
The frame would need to be old school with lots of power under the hood.
fat woody is the hot rod of the bike world
A vintage hot rod is typically a very unique, one of a kind machine. And while they may cost as much as a high-tech sports car to build, they attract a very different buyer. I can certainly appreciate the agile performance a high performance sports car, but there is something about the classic style of vintage roadster that the production sports car can't deliver.
Fat woody delivers that same sense of style that a production bike could never deliver. Like the woody beach hot rods of period, a fat woody cruiser has much of the cost wrapped up in its impeccably finished shell, not some ultra-lightweight carbon fiber frame. Simply stated, fat woody is the hot rod of the bike world, not the production sport or off-road bike.
It's a retro street cruiser that takes people back to a time when the styles were clasically cool. People will remember the day they saw a fat woody cruising down the boardwalk.
on-board wireless sound system / beverage holder
I think music is a really important component for a relaxing cruise. A simple solution would have been to mount the speaker on the handlebars pointed back toward the rider. I like the intention, but how uncivilized can one be. Next thing, people will want to hang beverage holders on their handlebars. Simply barbaric. That's like setting a can of beer on the dashboard. That's not to say my beverage isn't important to me, so I put my drink holder on the side (like a holster).
The unique design of the lower body component is shaped similar to a horn, and projects the sound upward. I was truly amazed that it seemed to direct the high frequency treble sounds crisply, while focusing the bass sound (pump) from underneath.
The result was high fidelity sound exactly where I wanted it.. my ears. Of course, the folks at Bose did most of the work with the wireless bluetooth and all. I just helped direct their superior sound waves to the ears of the rider. It sounds fantastic.
why should the fun stop at dusk?
Since the fat woody is a social e-cruiser, it would need some night time lighting. After all, why should the fun stop at dusk? A chrome cruiser style head light and classic tombstone tail light help keep the cruiser true to the era, but underneath it features the latest LED technology lighting.
Fat woody also features a functioning brake light whenever the brake levers are operated, and turn signals on the ends of the handlebars.
For those days when I'm not getting enough attention, I incorporated a 'look at me' mini motorcycle horn. Actually, some states still consider an electric-assisted bicycle a MoPed, and as such may require certain 'motor vehicle' functionality, like a horn, brake light, tail light and turn signals. Not necessary everywhere, but you're covered either way.
fat woody has a wide crank (what did he just say?)
While that may sound like another funny double entendre (and it is ), a wide crank kit was necessary to keep the pedals from hitting the beverage holder. I said earlier that some compromises had to be made, but the beverage holder would not be one of them.
These are typically used on gas powered bicycles outfitted with small 49cc engine, but work great for an ultra-wide e-cruiser with an expansive mid-drift. Also, the ultra-wide and comfortable tractor-style seats tend to spread your legs/knees a little wider, so the wider crank set actually feels quite comfortable for a leisurely cruise.
The fat woody is designed for cruising in total comfort and relaxation. There is nothing more painful than pushing your bare feet down on pedals with spikes. A flat pedal surface with a little anti-slip non-skid (like mild sand paper) is perfect for riding barefoot or flip-flops. It's these little details that make fat woody a true cruiser..
charge the battery anywhere
One of the first things an e-bike owner learns is that their powerful battery packs require an equally powerful battery charger. That little item is actually quite large and it usually stays back in the garage, unless of course you haul it with you.
But that's no problem on the fat woody e-cruiser. It carries it's 50v battery charger 'on-board'. Another reason to love that composite body is that it hides and protects unsightly items like that. This means you can charge your fat woody e-cruiser at your destination, or anywhere you can find a 120v power outlet. It even uses a standard electrical extension cord. Nothing special!
I keep a short 6ft charge cord in the cubby so its available for extra-long cruises.
premium leather ultra-wide saddle
Most bicycles have no suspension to speak of, and cruisers of the period where no exception. Because of their rigid frame design, every bump in the road is directly transmitted to your body. And while the softer fat tires may absorb a portion of those bumps, the seat must be designed to help absorb the rest.
The saddle is an incredibly important and personal item on a bicycle. It must have an ultra-wide tractor-style design to maximize support area, as well as rubber mounts and super soft padding for ultimate comfort.
As with everything else on the fat woody cruiser, it must be richly appointed. This means ultra-soft custom leather. Fat woody saddles are the highest quality, hand-crafted using only the finest leathers available.
the highest quality electric drive system available
First and foremost, the best e-bike on the market is the one you can easily get replacement parts for. I want to know that replacement electric drive components are available when needed. While there are tons of mass-produced e-bikes pouring in from overseas, replacement parts are nearly impossible to source. The replacement parts are not universal. They must be 100% specific to your e-bike, as your electric components must work together in harmony.
In the DIY electric bike industry, there are only 2-3 trusted suppliers. EM3ev is one of the best, with quality drive system components and great customer service. All the electric drive components on the fat woody are manufactured and supplied by EM3ev. In fact, they are also available for direct purchase from EM3ev, either by you or your local service shop. Of course you can get replacements from fat woody too, but its great to have multiple options.
the battery pack - quality is critical
Fat woody uses a robust and reliable 14.8Ah battery pack built by EM3ev. All battery packs are constructed with dozens of Li-Ion cells tied together to make one big battery. You've most likely seen news reports of what can happen when a cheaply-made Li-Ion battery pack shorts out and quickly melts down, sometimes even exploding. Every Samsung cell in the EM3ev battery pack has a fusible link installed. In an over-voltage scenario, the fuses will open and prevent a dangerous short circuit condition and potential fire. The BMS (battery management system) in the EM3ev battery pack ensures the cells can not be overcharged. And since most of us might park their e-bike in the garage of their home, its nice to have that peace of mind.
Very few battery packs are built with these safety features, and packs that do cost considerably more than lower price point packs. As for power, they are designed to deliver 50v @ 40A continuous. That's more than 2000 watts. You won't find a production e-bike out there with this kind of power... period. But then it's a hot rod.
cruising range / distance
Cruising range is directly proportional to battery size, meaning the bigger the battery, the more power you can store. But that doesn't really tell you how far you can go on a single charge. The truth is, there are a lot of variables that factor into an e-bike's cruising range. Are you on flat roads or hills? Are you going full speed or cruising slow? Are you on pavement or sand?
I like to think of the battery like a jet-pack and there is only so much rocket fuel to work with. In this case, 14.8 amp hours (Ah). Think of Ah's as simple units of power. You can mash the throttle and burn the them all up in 15 miles, or you can miserly dole out power units and stretch your distance to 35 miles.
The e-bike computer display provides all this power data in real-time. You can see exactly how much you used, how much you have left, and how much your using at that exact moment. What it doesn't say is how much further you can travel? That's because it doesn't know if you plan on mashing the throttle all the way home, or cruising slowly. Its all about how you manage your energy usage.
high torque geared hub motor
Fat woody uses the EM3ev Mac 500/1000w geared hub motor wound for high-torque applications. This means the massive power available from the battery pack above doesn't translate to speed, but rather torque. The gear reduction system allows the motor to spin at a higher and more efficient rpm greatly improving the starting torque and hill climbing ability when compared with less expensive direct-drive motors. An integral temp sensor provides critical information to the on-board computer system, rolling back power automatically when things get hot, minimizing any chance of overheating damage to your motor or battery pack.
The fat woody e-cruiser easily powers through sand and up hills without even sweating. The torque is simply phenomenal! So powerful in fact, that fat woody uses thicker 13 gauge spokes (vs. 14g spokes on other e-bikes). These thicker spokes also support much heavier riders, so no worries. Fat woody is for everyone!
is this kind of power street legal?
Power limits vary from state to state. That said, this e-cruiser's max power output easily exceeds what is considered to be 'street legal' in the U.S.. To comply with e-bike power and speed limit laws, fat woody incorporates a 3-position switch that allows you to choose between different modes of power. An on-board computer system allows you to custom program 'power/speed limits' in each preset mode. Here is an example of how each fat woody is set up in default operation.
Street Legal Mode - 100% programmable to meet your State's power & speed limit requirements. (e.g. 750W / 15mph max)
Off-Road Mode - 1500w - Great for hilly areas or grassy parks.
Unlimited Mode - 2000+w - What you need to power down a sandy beach.
That said, the street legal mode (typ. 750-1000w) is sufficient on level streets and roads. Anything less than 600 watts will be pretty disappointing, especially if you live in a hilly area. If you want extended range cruising, the street legal mode is what you want. It also delivers a smooth, progressive acceleration for less experienced riders and limits speeds to around 12-15mph. On the flip side, 2000+w to a high torque motor is like driving a hot rod. Be careful, as it can throw unsuspecting riders right off the back if they're not holding tight! This will easily push the fat woody e-cruiser past 25mph, unless of course you program a speed limit.
I did say fat woody was a luxury e-cruiser, right? Simply press the cruise control button on the console and you can let go of the thumb throttle. Fat woody will hold that speed until you operate your brake levers or press the throttle again, at which point it disengages immediately. I only recommend trying this feature once you're familiar with the lever braking system.
fat tires, fat fenders, fat woody
Fat tire bikes are equipped with much larger balloon-type tires that offer some great benefits. The larger tire patch (where the rubber meets the road) provides better traction and stability on just about any road surface. And if you run slightly lower air pressure in them, they can provide a softer spongey feel on an otherwise rigid bicycle frame with no suspension. They also perform beautifully on the beach, floating on top of the sand as you ride.
Most fat tire mountain bikes are fitted with off-road style tires that have a knobby tread design, which is great for serious off-road traction in the mud. But this is a cruiser style bicycle, and the knobs provide a rougher ride on hard surfaces. The less-aggressive tread design of cruiser tires provide a smoother, more relaxing ride.
retro-style cruiser frame
The first thing you'll notice when you ride a fat tire bike is that the increased tire height raises the bike up 2-3 inches. It feels like you're sitting way up in the air. I wanted it to feel more like a cruiser-style motorcycle, so I relocated the seat post to a more comfortable cruising position. Personally, I like being able to put my feet down at stop signs without having to get off the seat.
A cruiser-style frame with it's curved tube design would have a more relaxed feel than a mountain bike frame with straight tubes. Relocating the seat down and back provides a more comfortable cruising position allowing most riders to put a foot down without getting off the seat. It also helps us fifty-somethings get on and off the bike easily.
The more relaxed ergonomic posture would be better served with a retro-style cruiser handlebar design. With a lower rise, the 33" wide handlebars make the e-cruiser feel more like a Harley Davidson than a bicycle. If you've ever ridden a Harley, you know how comfortable that feels.
Builder's Note: There are some minor drawbacks to this ergonomic adjustment. Your seating position is more recumbent, so standing over the bicycle to increase pedal-force is not as easily executed. But then the fat woody cruiser is not what I would refer to as an exercise-focused bike.
Second, like a motorcycle, the seat height is not adjustable. If you have extremely long legs, that might be undesirable. I guess that would be a personal preference. But consider that you will only pedal the single speed cruiser up to about 6-7 mph. It's all e-power from there. Of course, you could also choose to not pedal at all.
upgraded disc brakes
Most single speed cruisers have a single rear coaster brake, but since the fat woody cruiser has a little power under the hood, I felt it was prudent to upgrade the brakes.
In the unlimited power mode, fat woody cruisers are easily capable of speeds over 25+mph. This power is intended for high torque (powering uphill or through sand), not speed. Unfortunately, speed is an unintended byproduct of that power.
It's easy to build an electric bike that will go 50+ mph. But is it wise? That depends on the bicycle's platform. Are the tires designed for it? How heavy is the bike? How well is the braking system designed - hydraulic or cable-operated?
Most multi-speed bicycle braking systems are cable-operated, not hydraulic like sport bikes, scooters, and motorcycles. A cable-operated braking system is more than sufficient for bicycles when speeds are less than <20mph. Once you get above >20mph, you had better leave some room for braking safely, especially with a heavy bike like the fat woody (90 lbs + the rider's weight).
Fat woody is designed as a low speed cruiser. If you want to go fast, get a lighter bike with a suspension. Cruisers don't have any suspension to speak of. Hitting bumps and potholes at higher speeds can easily separate rider from bike. I'm of the opinion that a bike should never go faster under power than it could be pedaled as it was designed.