Friday, April 18, 2008



I cannot stress to you enough how important safety is to most of us here. You will be exposed to open punishment from cagers and/or even the road if you don't "look before you leap". Here are some basic tips you might not think about. Don't wear synthetic clothes, because if you're burnt badly enough from your exhaust, the material could melt into your skin. Don't wear shorts. Do not drink alcohol; you will get a DUI, because even regular bikers must follow normal traffic rules. Be afraid of cagers, but don't be afraid to take up some room on the road... they will go around you regardless of how much space you leave for yourself. Never ride at night without front & rear lights. Regardless of the time of day, try to wear brightly colored clothes, or use a safety flag in order to make the elderly more aware of your presence. Always be completely aware of your surroundings. Always check for loose bolts or chains & any leaks, preferably everyday. Have good brakes & tires, and consider a chain guard to keep your pant legs from getting caught in a position you won't appreciate. Avoid loose gravel/dirt/sand/pebbles like the plague. And last but not least, don't forget to wear your helmet!!

Legality is a tricky topic. Certain assisted bicycles could possibly be allowed in one region of a state/province/nation, but not another. The extent of this guide really only allows for federal laws, because your individual city or state can place restrictions on something the national government hasn't regulated. As of now, the U.S. government has only allowed electric bicycles to fly under the radar of officers across the country. Some states & cities ban gas-powered bicycles, but Arizona is one state that specifically allows gas-assisted bicycles so long as the engine is less than the common 50cc limit. It is your duty to contact your local officials & even to inform them of laws your legislature has passed. Or it could also be your duty to persuade your legislature not to regulate assisted bicycles.

Choose Your Frame
Once you've figured all this out, you should consider what type of bicycle frame(s) do you desire. There are several: cruiser, chopper, mountain, road, bmx, folding, trike, recumbent, recumbent trike, or even unicycle if you dare. A thread discussing the differences between cruisers & mountain bikes can be found here.

Frame -vs- Rack -vs- Trailer Mounting
Next, you need to consider where you want to mount your engine. Many people choose frame-mounted for the aesthetics; they want something that looks like a motorcycle by filling that huge hole inside the frame. A V-style frame is usually easiest to work with frame-mounted engines. Your frame is probably capable of frame-mounting a 2-stroke if there is a 14" gap along the seat-post, from the top of the crank to the bottom of the top horizontal bar. Wider engines, like 4-strokes, will probably require a wider crank. Frame-mounted setups also don't easily work with rear suspension frames. Frame-mounted engines could burn your calves if you don't wear pants.

Rack mount kits tend to be more expensive than their frame mount counterparts, as they often use high quality (and high reliability) two and four stroke motors, and high quality components. These engines tend to require much less 'tinkering' than do the Happy Time motors. Also, the rack mount motors tend to keep a bicycle looking like a bicycle, and not a motorcycle 'wannabe.' Since the motor and gas tank are behind you, you won't be in any danger of burning yourself on a hot exhaust, and they are quieter for the rider. In addition, there is no need to worry about wider cranks. Drive systems for rack mount motors include chain drive (Staton-Inc,[others],) belt drive (Whizzer, Golden Eagle Bike Engines (GEBE)) and friction drive (Staton-Inc,GEBE, [others]).

There's also a less popular, but more versatile way to push your bike along, and that's with a trailer pusher. You can use any motor & drive system to accompany a simple, one-wheeled trailer that attaches to your seatpost. Simply clamp it on & hook up the throttle cable, and you can motorize almost every human powered contraption with wheels.

Belt -vs- Chain -vs- Friction Drive
As hinted above, there are many ways to connect the output shaft of a gas-powered engine to a tire: a belt, chain, or friction roller. Each has its pros & cons. Friction, or "Scrubber" drives, are the simplest to install. They employ usually a textured metal roller, supported at both ends by a bearing, that is directly driven by the engine. In operation, the roller is pressed against the tire, and friction between the spinning roller and tire rotates the tire to drive the bike. Unlike belt or chain drive systems, the only factor affecting roller system top speeds are the engine RPM and the roller diameter - a larger roller results in higher top speeds, while a smaller roller results in greater torque. Tire size does not enter into the calculation at all. Scrubber drives are less efficient than chain or toothed belt drives, as they increase rolling resistance on the tire. In addition, in wet weather, they can lose effectiveness and slip (and if misadjusted, can lead to tire damage). Finally, they do cause more tire wear than other systems. Evin if properly adjusted, you can easily get one to two thousand miles of wear on your tires.

Belt-driven setups tend to be regarded as the smoothest of rides, requiring virtually no maintenance, but sometimes a replacement belt is necessary. They also slip in wet conditions like friction rollers. Belts can also easily be popped on or off the engine's driveshaft for easy pedaling. Belt drives fall into two categories: V-Belt drives (used by Whizzer) and toothed timing belt drives (used by GEBE). The V-Belts are rugged, but are less efficient and require more periodic adjustment than do chain or toothed belt drives. The GEBE system (Golden Eagle holds many patents related to timing belt drives on bicycles) uses a very large timing pulley that snaps to the wheel spokes. The GEBE system is quiet and light-weight, but, it also requires a different riding style (no 'jackrabbit' starts, for instance) and it is recommended with motors less than 2 HP.

Chain drive systems usually employ a gearbox to reduce the drive sprocket RPM. Chain setups are the noisiest, heaviest, & hardest to install. And as long as the chain is kept lubricated with WD-40 or PB Blaster and the drive wheel is properly trued or balanced, you will have a very efficient, rugged, & snappy setup. More complex freewheel setups allow for a freewheeled pedal crank to bump start Happy Time engines or double freewheels on the rear hub for centrifugal clutches. Also, like friction rollers, sprockets can be swapped to gear toward greater torque or top speed.

2-Stroke -vs- 4-Stroke -vs- Electric
Then, you will need to consider whether you'd be best with a 2-stroke, 4-stroke, or electric motor. Size, weight, price, & being largely maintenance-free goes to the 2-strokes. You don't need to drain/change the oil; simply mix the 2-stroke oil with a gallon of gas at a time & keep on pouring until the engine stops purring. Most 2-cycle engines also win in the area of being able to bump start the engine by releasing the clutch lever while you're pedaling. 2-cycles are also best suited on a motored bike that folds & one that will be tipped or flipped. These 2-strokes generally allow for more horsepower, which means a greater top speed. This thread talks about how a 2-stroke will still win in a race against a 4-stroke of the same displacement, even if the sprockets are properly matched with the strengths of the specific type of engine.

On the other hand, 4-strokes make a pretty efficient motored bike due to their complexity. They get better gas mileage, more torque, & not only do they emit less noise into your surrounding, but also less pollution. Due to the nature of 4-cycle engines, you must change the oil. You might even need to do some valve adjustments. All of this leads to a generally more reliable system than a 2-cycle.

Lastly, we have the electric motor. There are both brushless internal hubs & external electric motors that are driven just like a gas-powered motor (chain, belt, roller). Its only limiting factor is the capacity of fairly expensive batteries. With time, Lithium Polymer batteries will become cheaper & their range will grow. Electric bicycles are virtually silent, are considered most everywhere as consumer product, not vehicles, and are one of our best hopes for saving the oil that we will never be able to reproduce [without an excessively wasteful cost in the conversion process].

Speed & MPG
You're prolly curious as to what type of speed & mpg you will reach with your setup. Chances are you'll fall inbetween 100~200mpg & 25-40mph. There are prolly some extremists who don't fall in these ranges because they want the fastest motored bike around. It's important to remember that bicycles aren't designed to travel 40+mph; these aren't motorcycles. Overall, it's tough to say what you should expect because your unique system will have its own efficiencies & inefficiencies, like engine/sprocket/wheel sizes & how much you actually pedal.


As most of you already know, 2-strokes need 2-stroke oil, & 4-strokes need 4-stroke oil. One of the best tips you can receive for oil is to follow the manufacturer's suggestions. The only real tip for 4-strokes is to change the oil after 5~7hrs for the first time break-in, and then every 10~25hrs thereafter.

2-Cycle oil needs to be mixed with the gas before pouring into the tank. For the break-in period of a gallon or so, use a tad more conventional dino oil only to make sure the engine is properly lubricated. You might even want to add this extra oil straight down the sparkplug hole, directly into the cylinder.

Mixing 2-Cycle Oil
To properly mix 2-cycle oil & gasoline, you're best off using a 1 gallon container, because mixed fuel that sits for longer than a month can go stale. Also, you should avoid gasoline that contains ethanol. To properly calculate the amount of oil you need, find your recommended gasil ratio, then divide 128 (number of ounces in your gallon gas tank) by the ratio. For example, for 50:1 use 128oz/50 = 2.56oz and for 25:1 use 128oz/25 = 5.12oz Fill the can a third of the way with gas, pour in your 3-6oz of oil, then fill up the can the rest of the way, and don't forget to shake well.

During break-in, you'll want to take it easy on the engine, gradually engaging the throttle more and more as time goes by. Always let the engine warm up, then ride it with just 25% throttle for several minutes. Next, pull the throttle about halfway for a short period of time, & then rest the engine after every 15 min of runtime. Repeat this process, making sure to let the engine warm up then cool down, Again, gradually engage the throttle more and more, but don't run it wide open for the first tank or so.

Switching To Better 2-Cycle Oil
After break-in, you'll prolly want to switch from regular dino oil to a full synthetic or 80% synthetic / 20% castor bean oil mix, but you certainly can stick with the regular dino if you so choose. Castor oil has its benefits, but I don't think too many people run their engines only with castor bean oil anymore. Some of the best brands of 2-stroke oil are Amsoil, Royal Purple, & Redline. The two best 80/20 synthetic/castor mixes are Maxima Castor 927 & Klotz Super Techniplate.

"Reading" The Spark Plug
You'll also want to learn how to "read" your spark plug. This essentially provides clues to whether or not your cylinder is receiving the proper air/fuel/oil ratio. Here's a site that shows you what the plug should look like, and here's another site.

Judging The Proper Fuel/Oil Ratio Based On Environmental Effects
You should also understand how to judge whether you need more or less oil in your mix, depending on certain circumstances. If you you will run WOT for a long time, you'll need more oil. Smaller engines need more oil. Higher RPM engines need more oil. Engines with a heavy load (i.e. - rider and/or trailer) need more oil. Warmer temps may need more oil. And elevation will also affect how much oil you need, because higher elevations have colder, denser air.

- Lacing a sprocket thru spokes works best with 10-12 gauge spokes, and it's commonly referred to as the "clamshell sprocket" since it's sandwiched between two pieces of rubber. Go here to find out how to drill your own holes for an odd number of spokes. Or PM the_wheelmaster for a safe & cheap bet on a solid clamshell job backed with a lifetime guarantee.
- Double freewheel setup, which could be welded together for a solid hub like Happy Times need (if you don't like the clamshell sprocket method).
- One & only freewheel setup for Happy Times
- Gear reduction

- Tranny comparisons
- Staton CVT
- NuVinci CVP hub (2) (3)
- Or you can just setup a ghetto transmission by using derailers or internlly geared hubs, tho with internal gears you must take it easy, at a minimum letting off the throttle while shifting.

- General tips for builders: use rubber/leather inserts for motor mounts, replace all cheap bolts/nuts with grade A US stuff, use Loctite, & take your time.
- Custom engine mounts
- Chainsaws, weedwhackers, etc.
- 2-strokes (2) (3)
- 4-strokes (empty, need links)
- Custom frames
- Old school motored bike book

- Mistakes we all make
- Tools for the ride
- Consider that a busted inner tube at an unexpected time is something you can avoid easily with thick liners or cut up street tires, thicker puncture-resistant tubes, or you could go way out there and buy AirFree tires.
- Don't get chain too tight or too loose. If you need to add/remove links in the chain, look for the master link with clip.
- Adjustments to brake cables will prolly need to be made after first couple hundred miles ridden on new bikes.

- Engine won't start? TROUBLESHOOTING GUIDE
- General horsepower thread(s)
- Homemade dyno
- Exhaust (2) (3) (4)
- Carburetor (2) (3) (4) (5)
- Remove governor (GXH50)
- Engine
- Leaky intake or exhaust (permatex 1A)
- Leaky gas cap (2)

- Lights (2) (3) (4) (5)
- Large's clutch mod
- Throttle
- Add pull start to happy time
- Double the gas tanks
- 1Gal Gas can as tank
- Toggled anti-theft killswitch, Keyed switch
- Very professional keyed ignition switch setup

- JohnnyGA's John Deere bike
- Graucho's beast & his greatest paint jobs ever
- Lhemrick's old school creation with sidecar
- Greenblazer's green fuzzy chopper
- Alan's super clean cruiser
- Azvinnie's Kustom Schwinn
- Blaze's Schwinn Stingray
- Zomby Builder's beautiful ride
- iRide Customs' custom ride
- Alaskavan's trike
- Papasaun's trike
- Azvinnie's "tri-brid" trike
- Bamabikeguy's trike w/ motor on front tire
- Willimoto's pocket rocket
- Nwguy's folding bike w/ motor on front & double the gears
- Smallest motored bike ever
- Simplest weedeater build ever
- Srdavo's chainsaw build
- Electric pedal assisted road bike
- Eric Peltzer's open source electric bike plans
- WIZARDOFOZONE's electric bike idea
- Simple trailer pusher
- Complex solar-powered trailer pusher idea
- Motorized unicycle

- Electric Motors/Batteries:,,, Cyclone Kits
- 2-Stroke Engines: TLE33, TLE43, Rob/Subaru, Chung Yang @ Staton-Inc, GEBE,
- 4-Stroke Engines: GXH35, GXH50, Rob/Subaru @ Staton-Inc, GEBE
- Kits: Staton-Inc, GEBE,,,
- Regular Bikes:, WalMart
- Pre-Built Motored Bikes: Spooky Tooth Cycles, Whizzer Motorbikes,,
- Oil: Maxima Castor 927, Klotz Super Techniplate
- Parts & Accessories: WalMart, Staton-Inc, Kings Motor & Bicycle Accessories, NuVinci Hub, Cheap speedo gauge, Airfree tires, Bike stand, Tires, DIY Trailers, Chinese 2-Stroke spark plugs

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