Cycling
From Steal This Wiki
note: this is all new material, and does not appear in the original book
The bicycle is most popular vehicle in the world, and for good reason: bicycles are beautiful things. They are cheap, reliable, faster and easier than walking (and driving in the city), and downright sexy. They can take you almost anywhere, they don't rely on fuel, a license or insurance, a most liberating way to get around these days.
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Getting a Bike
Always acquire your cycle through honest means, a less than affluent person can be have their life or job ruined by stealing or stripping their cycle. Don't assume that a nice bike belongs to the CorpGov rich and is thus free to steal, many of us put every penny and a bit of our heart and soul into making one of our few material treasures into a work of fast functional art.
Find a bike of quality good enough to not require constant replacement of parts. If the quality is too low you will likely learn to hate cycling and stay a petrol hog. Generally it is a better idea to decide if you are only going on road, since there are many different types of bikes for their use. Road bikes are for roads, and vise versa. A good compromise is a heavy mountain bike frame with road tires, this is pretty much what a hybrid bicycle is. Keep the knobby tires to swap on if you ever move to an area with mostly mud and dirt roads, or sell them.
Never buy junk from department stores that rely on crude slave labor: these are designed as gifts to kids who will likely ride them for a few weeks, these garage rusters tend to be good for only about 500km and maintenance is almost impossible.
When buying, stick to a friendly local bicycle shop or, even better, a local bike co-op who will sell you a tuned and sized bicycle designed for long service life.
In the USA, quality barely used bikes are discarded to "thrift" shoppes which may sell for as little as $10. Garage sales are also a good source of cheap bikes, beware the used department store type cycles unless you need a disposable with poor performance. A proper 1970's vintage quality bicycle and a little tuning is a much better choice for your money than a brand new discount-mart special.
Watch out for dents in the frame of the bike, this is a sign that the bike has been crashed, and may be hazardous to ride especially if it is of aluminum or exotic construction. Also look out for hairline cracks in the paint, especially near the tubing joints. These can be an early warning of frame damage.
A good way to get a bike is to put up ads on bulletin boards. Something like "looking for reasonable bicycle for reasonable price" is good. This only works if you (or your buddy) has a phone or email. Get your local bike shoppe to check out a bike you are about to buy and estimate repairs and tune up.
Yellow-White Bicycle Programs
Find out if cities you are traveling to offer a Yellow Bicycle Program. Furthermore, if you find yourself a new local in a larger city, think about aiding those following your traveling example and start up a Yellow Bike Program in your new town. To do this, you can either approach city official yourself with the idea, or simply start it up without them. You'll need some cheap yet solid bikes, and some yellow paint. You can draw up a small map of suggested pick-up and drop-off points in town for the bikes, like public/school/park/downtown bike racks, fences by vacant lots, etc. Tagging some of these places with a minimal yellow stencil design can help, too. Encourage friends to look out for the welfare of the bikes if they see them tossed or crashed-up, either reporting to you are fixing them themselves. You can also attach a little sticker or tag to every bike before you put it out explaining the ideals behind your program to prevent wanton theft or destruction, and also encourage visitors to follow your example.
A good idea is to paint every part of the bike even pedals and tires to reduce theft, resale, and stripping value, be sure to mask areas able to be damaged by paint. Single speed coaster brake bikes have the lowest moving part count and the highest resistance to abuse, unless you are in a very hilly city this is the best type for a yellow bikes program. If possible include some sort of front baskets, folding wire pannier baskets, and such to allow shopping trips.
Most programs in anything other than a tiny town or community result in many lost bikes, you may have to consider moving to a free membership program, order dozens of locks with the same key and require a library card proving that the member is a local to join the club and receive a key, this will slow down random vandals and thieves but will also stop the short term traveler from easily acessing a service they need most.
As a last option collect and fix junk bikes so you have a supply to give to travelers and locals letting them know that an unused or unneeded bicycle would be best utilized by returning it in good condition.
Kinds of Bikes
Upright
The least expensive and easiest to obtain new and used is the regular upright bicycle. Road bikes are equipped for speedy travel and have multi-position hand grips and razor thin tires for cruising along paved highways. Mountain Bikes come in several stages of impact and mud resistance but the shocks and knobby tires are adapted to off road travel and you will waste a good percentage of your pedaling effort if using a mountain bike as an urban commuter. Hybrids or urban commuter bikes take the ruggedness of a mountain bike to absorb potholes and curb drops and add the road capable tires and sometimes the multi-position handgrips for long trips. Touring bikes can also take some of the attributes of both mountain and road bikes usually with emphasis on long riding but with stronger components and mounting points for pannier bags.
Cargo Bikes
Cargo bikes can take many forms but they are usually based on some sort of a tricycle. Many of these are custom shop build jobs with either the front or back half of an inexpensive conventional bicycle removed and a large cargo area added. For front cargo the front wheel and forks are removed and a tubular frame is welded on, the front wheels are mounted on the sides of the cargo area and pivot on their mounts, a cross tube/handlebar attached to these pivots is pushed left or right to steer, these bikes have a very limited turn radius and are best for use in an area with few hills, but can be made with quite a large cargo capacity. A traditional tricycle design requires a bit more mechanical skill since a drive axle with a chain sprocket must be installed, the available cargo area is limited by the width of the axle, these are also available from specialty bike shops. There are frame attachments which make for a long tail bike allowing very large panniers or several buckets or coolers to be attached to this extension, the upside is that it is possible to quickly convert back to a normal bike with a trip to the bike shop but these extensions appear to put stress on the rear of the bicycle frame.
Recumbent
While still almost universally expensive even when purchased used; if long haul travel is in your plans the recumbent is definitely worth looking into. Imagine reclining in a nice lawn chair and pushing out to the pedals instead of crouching over your handlebars, this is the position of a recumbent rider. You will be able to put much more of your leg power to work pedaling your clipped-in feet sitting recumbent than you ever did on an upright. The only major downer with recumbent is that they are low to the ground so the rider is at bumper level and you are unable to stand up on the pedals to gruff your way up impossible climbs. Another bonus to recumbent is the ease at which battery powered and regenerative drive systems can be added due to the multiple drive chains. We have even seen stirling, steam, and gas booster motors added although this takes from the whole green purist idea.
Hybrid Power
Blurring the borders of bicycle, motorcycle, and car; vehicles like the Twike and other custom lightweight hybrid vehicles let two or more riders travel in style. Riders are inside an enclosed and stylishly interiored vehicle, a battery and motor system give a big power boost to uphill pedaling and recover energy from downhill braking back into the battery. On a sick day plug in and charge your battery for a free ride. We expect you enterprising types to get out your welding, electrical, and plastic forming gear and design more vehicles like this to take back our streets and clean air.
Protection
Helmets
Most people feel that a helmet is a necessity for riding. Though cycling is a generally safe activity, the most likely cause of fatalities and debilitating brain injury in bicycling accidents is head impact, and helmets will reduce the possibility of this by 88% or stated another way making you brain nine times safer. Helmets can be purchased (in the US) just about anywhere bikes are sold. Make sure you get the helmet adjusted correctly; it needs to fit well on your head to be the most effective. Helmets are only good for one crash: if you hit your head with your helmet on, you will need to replace the helmet. For this reason, it's probably not a good idea to buy a used helmet.
One of our editors was in a serious accident where she was struck by a car, the helmet cracked badly but protected her skull that would surely have been broken damaging her vision centers and blinding if not killing her, as it is she has a limited field of vision in one eye now. The helmet made the difference between collecting thousands of dollars and collecting a hole in the ground.
Gloves
It's a wise idea to wear gloves to protect your palms in case of a fall. Grazed palms may not be life threatening, but they will impact every facet of your daily life until they heal. Gloves also ease the stress from a long ride.
Toe Clips and Clip Shoes
Anything you can do to keep your foot centered on the pedal will give you more power, toe clips also extend the length of your potential power stroke to allow a little bit of upward stroke. Clip shoes just amplify the benefits of toe clips giving a very firm lock to your pedals, clip shoes also do not wear out the sole when you are using them to pedal. The downside is small once you get used to these types of pedals but you might fall down getting used to having your feet stuck down, getting out of both clips and shoe pedals requires a twist motion that will become very natural after a few days of use. Clip shoes have another downside in that the metal plate doesn't grip cement like rubber when you are on foot.
Lighting
If you are going to be riding at night, it is very important that you work to make yourself visible. Reflectors, reflective tape, and lights are all helpful. For starters, a good, flashing LED taillight will help car drivers see you when they approach from behind. You can get one for about two bucks that will run a long time on a set of batteries zip-tie on or spend more for a proper mount.
HID Lamp
HID Super Bright xenon gas discharge lighting is the envy of many serious cyclists but the $400 price tag puts most of us off. It is possible to make a HID light set on a moderate budget. Auto shops and auction sites will occasionally pull good singles of a blown out HID headlight pair, we have seen them for as little as $30. These are relatively small and light, only draw about 3 amps at 12 volts, and have everything you need except batteries a reflector and mountings. A reflector can be made form a glass halogen track light with a reflector large enough to fit the xenon bulb, be sure there is a glass front lens, saw off the bulb end with a dremel tool and epoxy in the new bulb. New matched lithium batteries like the kind in a laptop will be perfect to power this high power lamp, batteries and ballast pack should fit inside a cut open water bottle.
The HID light is also the type used by pro videographers, mounted to their camcorder, or for lighting large areas at night like for plays, but for a much lower price.
Sound Signals
Invest in a loud horn or whistle, there are several pumpable marine horns or the Zound pumpable bike horn, Survival or sport whistles are better if you need to signal constantly in an urban area.
In highly populated urban areas, barking at jaywalking pedestrians works a treat. Most people freeze when they hear a dog bark up close, giving you the time to take evasive action. Plus it's free!
Carrying things
You can increase the usefulness of your bike by making it easier for you to carry loads with it. Racks, front and back, can be added. You can get bags (called 'panniers') which attach to the sides of the racks; these will allow you to carry a lot of stuff without encumbering your hands, allowing you to ride safer. For day to day use a small backpack or fanny pack will do.
Baskets
Baskets are also effective for carrying stuff. You can get baskets that attach to the front or back of the bike. Milk carton crates make good tough baskets when cable tied to your handlebars or tail rack.
Trailers
For carrying larger stuff (like children and furniture), you might want to consider a trailer. These can be expensive, but you can also make one yourself. A trailer can be pieced together with plastic piping or electrical conduit, a pair of spare wheels, and a basket or plastic tote. For a trailer hitch, go to your local hardware store and get a quick-release garden hose or air hose connection and a bit of hose. Rig up the connections to be used as a trailer hitch. For added safety, paint the trailer a bright color and put LOTS of reflective tape and a small red flashing light on the back.
Instructables.com has a number of plans for bicycle trailers and trailer hitches.
One company in Eugene, Oregon makes a hard shell suitcase for folding bicycles that when unloaded and wheels are attached becomes a bicycle trailer.
A two wheel stand-up shopping cart of the type used by retirees to take their groceries home is perfect for the cycle commuter. An extra handle is clamped or welded to the frame, this handle will end in a pneumatic hose fitting, the counterpart will be mounted to the frame of your bicycle for trailering. It will extend the life of your wheels to add greased brass or copper tube bushings to the plastic wheels or ball bearings. When you get to the store lock up your bike, unsnap your cart and take it in for shopping. When you get home your trailer/cart comes inside with you. It's easier than car shopping!
Bucket Panniers
You can also make large panniers from square food buckets and attaching hooks to grab your tail rack, properly caulked these will survive even the worst rain storms dry.
Cargo Mule
The Viet Cong made using a bicycle for cargo transport famous by traversing the Ho Chi Minh trail transporting their war supplies south at times almost exclusively with heavy laden bicycles.
Your bicycle becomes a push wagon and you have to walk. Try to balance the load as best as possible since it will be difficult if a very heavily laden bicycle were to fall over. Watch for bags or containers that might rub against your tires or spokes destroying your wheel and cargo.. Several hundred pounds could potentially be carried, nearly every adult bicycle is designed at a minimum to support over three hundred pounds of human rider. Attach a pole tightly across the handle bars to help steer, keep the brake handles reachable if you are in hilly terrain. Two pushers are better than one for balance. With loads over two hundred pounds be careful when using a bicycle with shock absorbers so they don't overload, be sure to have the tires at full inflation to prevent damage, and that the spokes are tight and aligned.
Anti-Theft
Types of Locks
A good lock is an important investment. 3' of hardened steel chain and high security lock gives options when securing your bike, and they're more affordable than a D lock (aka U-lock). The best place to carry a chain lock is in a pannier or basket. If you need to 'wear' the lock, then wear it around your waist. Wearing the chain across your chest may look 'cool' but in a crash can easily break your ribs and possibly puncture a lung.
Wearing a u-lock is easy; mini u-locks can fit into a back pocket. Another popular option is to place the lock in the space between your belt and pants waist band. We have seen a u-lock belt holster that is pretty easily replicated if you can sew, it is made from recycled seat belt strap with two loops to slide a belt through and then strap parallel to the belt to stick the lock into. Wearing the lock is not always comfortable for long rides, many rear cargo racks have space for a U lock to slip into otherwise most locks come with a clip and strap system to attach to the frame.
How to Lock Your Bike
A D lock should be run through the frame and high security cable through the wheels for good general security. Remember your D lock and to a lesser extent security chain is a self defense weapon if you are under attack.
Disguising Your Bike
Taking corporate logos from a new cycle and adding stickers and tape will quickly make it look used and reduce the perceived value and risk of theft.
One method people have used is to "uglify" the bicycle by painting it a hideous color combination (such as mismatched florescent colors) with added flecks or using a simulated rust finish available in craft stores. If the thief thinks your bike isn't worth stealing, he probably won't steal it and instead make his way to the Shimano further down the rack. Replacing the bolts on your seat with Torx head bolts will show down, or even deter, a would-be thief. Grinding off the logos from the gears; a worn, fugly looking seat; mismatched pedals, tires and handlebar grips; all of these can make your bike look like an ugly duckling while keeping it riding like a swan. Remember, don't think "art bike" here, think "camouflage".
Other Smart Tips
Don't leave all of your lights, pumps, seat bags, and other gadgets clipped to your bike when you are parked. They are quick release for a reason, and not to make theft easy, keep this stuff ready to go in your bike messenger bag. Just in case attach an extra red flasher to the back of your helmet where it won't be easily stolen, keeping you legal.
Gears
If your bike has multiple gears, use them! Pedaling shouldn't be a huge chore. It's better to lightly "spin" your cranks at a moderately fast cadence rather than push really hard one leg at a time, which is inefficient. It is possible to spin too fast: experiment with your gears to find what works best. Most people find their favorite cadence between 1 and 2 revolutions per second.
Demonstrations
A cycle is a highly effective means of transport to and escape from a demonstration it can also be used to make a roadblock much as bicycle cops are known to do. Use an old bike for demonstrations as riot-police like to damage and confiscate bikes used in demonstrations.
Travel
If you travel frequently a folding or take-apart model of bicycle may be for you. Some can even be disassembled or folded to fit a suitcase or duffel-bag. This may save you a double fare or extra charge on airplane, bus, and train trips as well as hitchhiking a ride. If disassembling a bicycle for travel be sure to take off the derailleur as this is very easily broken when unprotected by the wheel. See Airlines for more travel packing info.
Cross Country Camping
A favorite way to cross long distances is to pedal and hitch rides during the day and stealth camp using a hammock and maybe a tarp rain cover or bug screen at night. Smart use of stealth and hidden by brush in industrial, rural, or wilderness areas means you don't pay for hotels. With some light backpacker gear in your panniers and smart use of dumpster diving and social engineering at restaraunts you should be able to travel nearly any distance for free. see Backpacking and Camping
Tent Trailer
This trailer system is not as lightweight as a hammock and tarp for cycle campers but it provides a trailer and shelter for those who must carry all of their possessions with them as they move and also want a quick comfortable shelter without needing to find trees, or level ground to make camp. The tent-cot-trailer was originally designed as a temporary measure to house the urban homeless, it should also serve as an outwardly aesthetic alternative to stealth camping for cross country travelers.
An excellent platform to use a base for your DIY trailer is a lightweight folding cot. You will need to attach a trailer tongue to connect to your bicycle, many people like to use an air hose connector so it is easy to quick release. You will also need to properly attach an axle and wheels in a way that they can easily be removed to convert back to a cot. Perhaps the best source for an axle is from a discarded jogging stroller, often these bicycle type wheels even have a push button release. When attaching the wheels you will need to reinforce the light aluminum frame with some steel electrical conduit where it will be attached to the axle so the aluminum is not deformed when heavily loaded, reinforcing the trailer tongue attachment point would be advisable as well, be careful if using U-bolts not to over-tighten them. Folded down this trailer is easily loaded with food, fuel, and camping supplies. Secure everything using straps and a tarp, a large tied down duffle bag, or camping backpack, unload and unfold at nightfall and you have a comfortable sleeping cot anywhere.
An inexpensive dome tent can be modified to fit the cot trailer. Try to find a tent with a footprint as close to but if not exact then slightly larger than your unfolded cot/trailer so you can hem it smaller. Measure and pin the tent to be sure your estimates were right, then mark and take in the excess fabric by sewing a pleat with a sewing machine and good thread reducing the wall size to fit the cot, use seam seal on the new seam to prevent leaks. You might need to remove or reduce the size of the tent floor, the pole length might also need to be changed. Secure the corners of the tent to edges of the cot.
If in an open area where strong winds are possible leave the trailer hitch attached to your laid down bicycle so it will act as a anchor to prevent the tent-cot from blowing away, heavier winds will require stakes to be pounded into the ground as anchors.
Keeping it Working
Once you have a bike, you'll want to keep it working well. One of the most important aspects of bike maintenance is the lubrication of the chain. Almost any cheap oil will work in a pinch to keep the chain moving freely and free of rust: just get the chain nice and wet, then wipe it dry, to reduce dirt buildup. Try to keep the oil off the wheels where it can hurt your ability to brake. If you have the choice buy a proper bicycle chain oil and grease to lube the bearings and chain, only use WD40 to unstick rust jammed parts then clean it off and oil the chain, WD40 draws moisture and encourages rust. Replace a chain that becomes "stretched" this means that the link pins have become partly worn-through, this link to gear tooth size mismatch will eat up the sprockets of your drive train causing skipping and eventual failure.
If you have a problem repairing your bike, The Sheldon Brown Website is probably a good place to look for guidance. Sheldon Brown (1944-2008) was one of the best technical authorities on bicycles and he will be missed. http://sheldonbrown.com/articles.html
Tools
Owning your own tools makes maintenance less expensive. Plus, many tools you use on bikes, like pliers, wrenches and screwdrivers, are not bike-specific, so they will be useful for all kinds of other things, too. Some bike-specific tools, such as spoke, freewheel, and pedal wrenches and specialized brake tools, will make maintenance much easier, and you'll be more likely to do a good job. Many cities have bike co-ops or shops where you can use their tools for free or for a small fee.
Portable Tools
It never hurts to always carry the kit for changing a flat tire. At a minimum carry a small quality puncture kit and mini pump, but also carry a spare inner tube. Repair the flat tube in the comfort of your own home later, but don't forget to put it back in your pack for spare. Folding combo bike tools will provide spoke tighteners, chain breakers, hex and screw drivers, sometimes even sockets or wrenches. A small toolkit can make the difference between being mobile in a few minutes or a long walk home.
If you will be away from support for a long time you might even go so far as to carry extra tubes, a spare chain, brake pads, a few spokes, folding tire, and extra patch kits.
Road Crud
Beyond tools, it's important to do simple things to keep your bike in working order. Grit from the road sticks to your bike and its parts, even if you've got full fenders. Once a week, or after every ride in the wet, clean off the gears and the chain. An old toothbrush (clean it off first if you've used it before) and a rag will do wonders. The main place to focus on is in the actual teeth of the gears, most especially in between. Getting rid of all this destructive crud will increase the life of your gears and chain, and subsequently save you money and hassle. This takes all of ten minutes to do and is completely worth it.
Rust
Stopping rust also helps: if there's any exposed unpainted or unfinished metal on the frame of your bike, you can touch it up with a little hobby paint. This isn't for cosmetic purposes so much as preventing rusting. Rust eats away at your bike and can compromise the structural integrity of the frame, so watch out: the last thing you want is for your frame to break while you're in traffic.
Wheels and Tires
Bike tires lose pressure over time. Pump your tires up to the maximum PSI rating marked on your tires once a week and you'll never have to worry about it. Keeping your tires inflated properly reduces rolling resistance, which means less work for you when you're pedaling. It also means that your wheels and tires are going to stand less a chance of being damaged due to extra stress on them. If you have the money invest in the best tires; Kevlar and good rubber will prevent blowouts and tread failures while lasting for several seasons. Check your spokes regularly for tightness and tighten with a spoke tool, since this will keep your wheels from warping or ripping out other spokes.
Generators and Dynamos
A bicycle generator or hub dynamo can be used to charge most gadgets needing less than 6 volts. Hubs are almost always of better quality and have less drag while in use. Output is almost always AC power so you need to make a bridge rectifier with diodes to get the power flowing in one direction then a large capacitor if you need to smooth out the voltage, lastly a ziener diode or power regulator circuit for the appropriate voltage needs to be included because high speeds can generate 10-12 volts from a normally 6 volt generator which will fry most electronics without built in protection circuits, you can probably be able to find this whole circut in a wall wart power block. If you don't want the added drag of generating when going uphill add a mercury switch on a dynamo hub set to activate only on flat and downhill.
Friction dynamos/generators will rub a groove onto the side of your tire and eventually cause it to fail if used regularly, a rubber dynamo pickup wheel and cleaning dirt from the rubber contact surfaces will prolong the life of your tire. Some older friction dynamos rode directly on the tread but this would require a smooth tire instead of a mountain knobby type.
If you attach your generator to your rear tire you can generate a little power even in your squat by flipping your bike up on its saddle and handlebars and turn the crank with your hands. A minute or two cranking should power a small radio or LED nightlight for an hour or more. Charging phones or batteries would of course take more time cranking or cycling.
If you still have a car but no fuel pull out the alternator and battery and put your bike onto a stationary bicycle exercise stand conversion system, you can always reinstall the parts in the car later. Remove the friction belt and attach the alternator with a short V-belt, this may require cutting a groove into the excercise stand flywheel. You will be able to keep your battery charged to power whatever 12 volt gadgets you need. We have seen experiments where laptops and small TV's are powered by the operator pedaling with such a system. An automobile alternator requires some input voltage so a 12 volt battery is required in the system.
Nutrition
Stay hydrated and fed while cycling, don't waste your time with lo-cal foods; you need fuel, around 7000 Calories is reasonable. If it does not cause you indigestion try to eat lots of fats. A banana can help prevent cramping from long rides. Backpack drinking systems are available now for low prices if you prefer using these to water bottles, these make it easy to sip all day so you can drink all that you need. Many sport drinks come in a decent squirt bottle that fits standard bottle cages. See Backpacking and Camping and Cheap Chow for food and drink suggestions. If you will be going through towns be sure to do some dumpster diving especially at pizza, bakery, and donut places; stock up on the free fuel.
Have some baking soda for indigestion; witch hazel for hemorrhoids and rub spots; oatmeal, coconut milk or another laxative if you get backed up, which happens easily on the road eating less fiber and dehydration. You might want activated charcoal or other medicine for diarrhea mostly from forgetting to wash your hands or strange foods.
Motor Assist
If you want the portability and freedom of a bike with some of the ease of a motorcycle, no worries. Almost any bicycle can be converted to an electric power-assisted type (basically a moped) for a few hundred dollars. Various people have added old or new purpose bought weed-eater type engines to power-assisted bikes with positive results, but keep in mind that two stroke engines which burn an oil gasoline mix do pollute the environment significantly although Honda and Subaru four-stroke motors are much cleaner and consume normal gasoline. US rules now ban the import of most new two cycle engines but they are still available in Canada.
The two main methods for power transfer are a friction roller which is directly against the tire necessitating a smooth tread, or chain drive to the wheel, some kits have a sprocket which connects to the spokes, the better way is a specially modified wheel with a free wheel sprocket for the drive chain. Another type is the "push trailer" which is a gas engine or electric motor on a trailer that is towed behind the bike and pushes it forward, using a handle mounted throttle for a control. These are often DIY jobs as the kits are usually quite expensive, but be sure to get good instruction and guidance before doing this on your own. If the purists turn up their nose point out the idea of NEVER needing to use a car even in steep mountainous terrain where most would not even consider a bicycle.
Installation
Installing a motor puts stress onto your frame and rear wheel, expect much shorter life from your spokes if you are attaching a sprocket to them. Designs which have a special rear wheel with normal and motor sprockets on opposites will last longer. Pedaling is more difficult against a chain drive system even when the clutch is out. Friction drive systems quickly take the tread off of your rear tyre and often stop working in wet weather.
Folding Moped
A small bolt-on motor attached to a folding bike would make something similar to the WW-II Welbike motorcycle used by OSS and paratrooper commandos, with the added bonus of you being able to pedal when you run out of fuel or on the flats. The short spokes on small folding bikes are stronger and will take more stress even if a cheap spoke mount sprocket is used. Remember that small folding bikes have a low center of gravity and short wheelbase and take a while to get used to.
Magneto Electricity
Look for a motor with a electrical output from the magnetos to run a light or charge batteries, this electrical output is AC power often only six volts and needs a rectifier circut to be used by most things other than a regular headlight.
Legal Motors
If you are desiring to be a legal eagle, some localities prohibit any motor under 50 cc to be used on the King's...er...Federal Highways. Furthermore, any person operating two-wheeled vehicle with a motor greater than 50 cc must have a motor vehicle license. Some states require a motorcycle license regardless of the engine size, while others require only a passenger vehicle license. Most two-stroke engines are generally less than 50 cc, and most electric motors would be considered in the same category. Since laws differ with each jurisdiction, contact your state or province's Department of Motor Vehicles about their regulations on mopeds and "motor-driven cycles". If your motor comes unmarked a professional 49cc sticker or etching might throw off nosy cops.
Exotic Propulsion
If you are bat fuck insane like me then you might consider a jet engine. These can be made from car or truck turbochargers for 100-300 dollars. They will provide considerably thrust- a four inch engine will give 300 pounds, with a afterburner it becomes 450. This is most likely illegal to stick on a bike but the point of having a jet is to escape, not to worm your way out. This is also dangerous, with high temperatures, and speeds...
Another idea is to add a balanced power take off shaft to the "turbo"-jet and generate power to charge a hybrid vehicle or even power your whole commune. Or just build the jet powered Bat-Fuck-Mobile....
http://unitednuclear.com/jetplans.htm will soon have plans for sale
