I live about 10 miles away from my job which meant I was using about a gallon of gas a day just to get to and from work. I figured there had to be a better way. I looked at electric bikes and conversion kits but the cost was way more than I wanted to pay. Then there was the 49cc 2-stroke conversion kits. I found these as cheap as $140 but wasn't really sold on the idea of altering the bike so much. Then I remembered the "Stinger" from my childhood. These were friction drives we bolted to the back of our bikes. I started doing a little searching and found friction bikes of all kinds on YouTube. These were various motors mounted to the back of the bike with a peg on the output shaft making constant contact with the tire. This meant that every time you stopped the bike you would have to restart the motor. If something happened to the motor you would have to get off and adjust a turnbuckle to ride the bike normally. I wanted to ride the bike powered or un-powered at any time and not have to restart the motor every time I stopped. So after watching countless videos I came up with my own idea. I would incorporate some kind of clutch system in my friction bike. Presented here is what I came up with. Unfortunately I failed to take pictures during the build so I only have pictures from the finished project. By the time you finish this instructable you should have a good enough understanding of the concept to build one yourself. If you already have a bike and a motor and do some salvaging you should be able to complete this for around $50. Here is what I used:

GMC Denali 700c Road Bike

26cc Weed Wacker Motor

Schwinn Seat Tube Bike Rike

1 x Sunlite ATB Shift/Brake Lever Set - 1 Pair, 3x7-speed, 2 to 1, Black

1 x Tektro RX 4.1 Reverse Brake Levers Black

Bell Shift Cable Kit

1/2" Aluminum "U" Channel

1/8" x 1" Aluminum Flat Bar

Misc. Nuts, Bolts, and Spacer (I used all stainless steel but you can you what you have}

1/2" Plywood (A piece of scrap)


Cable Clamp (Salvaged from another bike)





Tape Measure

Step 1: Mounting The Motor

Before mounting the motor I cut away the parts of the plastic casing that I didn't want. Next I attached a bike axle peg to the crankshaft. The way to do this depends on the motor you are using. For mine I threaded the the end of the shaft with my tap and die set. I then slipped the peg over the shaft and used a nut and a nylon lock nut to hold it in place. Once you decide on how to attach your bike peg you must make a way to mount it to the bike. Using a piece of cardboard as a pattern, I designed a swing arm, that I cut from 1/2" plywood. I have included the pattern I designed. I then mounted the motor to the swing arm then attached the swing arm to the bike rack mounting bracket. I used a long bolt and a spacer, made from a piece of copper pipe, to align the arm to the wheel. This swing arm system will allow the motor to be moved on and off the wheel by using a lever on the handle bars. In the next step we will mount the rear support system.

<p>This is a great little instructable and very clever :) However I have to warn people (for the UK at least but I believe the laws are similar in the USA?)</p><p>Any bike that is powered / power assisted with gas/petrol requires you to have a drivers licence (for a motorbike), for you to wear a crash helmet (technically anyway), and to have a licence plate, insurance and tax.</p><p>Basically, any conversions that involve high voltage (&gt;250w in eu, &gt;750w in usa) or gas/petrol will be treated as a moped/motorbike, which will increase the costs significantly; and gives the police the right to confiscate your bike on the spot if you cannot produce the relevant documents.</p><p>I'm not trying to knock this instructable because it is really really cool, as well as shockingly cheap, I'm just warning people. I'm trying to get an electric bike myself and I've had to do a lot of research into the laws around them. It sucks.</p><p>Thank you for sharing this instructable anyway :)</p>
<p>Sorry to say but I don't know where you got the idea that the laws are similar une UK and US ??<br><br>The truth is that the laws in are much more different you might think ! In the US they pretty much can do what they can do in term of custom bikes. Under 49cc, it's considered a moped; no drivers licence, no licence plate, nada !</p>
<p>Depends on the state. Here in California if it's capable of speeds over 20 MPH it is a moped that requires an M2 motorcycle endorsement (vs. an M1 endorsement which is for motorcycles over 150cc) in addition to your regular driver's license. Also here, while bicycles don't require licenses, they are considered vehicles and you are subject to all traffic laws (including DUIs) while riding them.</p>
<p>When I said that &quot;I believe the laws are similar&quot; I mean't it in the fact that both areas have restrictions on wattage and gas/petrol limits.<br><br>If you read my entire comment, you can see that I mention the differences between the EU and USA when it comes to wattage (250 vs 750).<br><br>When I say that they have &quot;similar&quot; laws, it means that they both have laws revolving electric bikes, both having restrictions on the same types of things. The severity of the restrictions, however, is dependant on each location. The USA, while having far more loose restrictions on electric bikes, do still have restrictions before they are considered motor-bikes and require driving licences to use. They can not do pretty much anything, they can just do more than the UK/EU, for example.<br><br>I hope that clears things up.</p>
Thanks Rarnd, and yes, you are right, everyone should check their local laws as they are different depending on where you live. Here in Illinois, USA, you only need to be a licensed automobile driver, the motor must be less than 50cc, cannot reach over 30mph in a one mile stretch, and cannot have a transmission that lets you change gears. No tags or insurance required. There is no helmet laws in IL for motorcycles or bicycles. As far as E-Bikes go, anything goes there. We can have 6000w on our bike, as long as it is electric only and has pedals, there is no restriction, unless of course it is an electric motorcycle then the rules are the same as any other cycle. Again, these are IL laws and yours will probably be different.<br>
<p>And my country has different laws just depending which state you're in.<br><a href="https://www.sa.gov.au/topics/transport-travel-and-motoring/cycling/riding-a-power-assisted-bicycle" rel="nofollow">https://www.sa.gov.au/topics/transport-travel-and-...</a><br>My state for example:</p>Riding a power-assisted bicycle<p>A power assisted bicycle (or power-assisted pedal cycle) is a pedal cycle with a motor attached to assist the rider. The attached motor may provide assistance but the pedals must be the main means of propulsion.</p><p>In South Australia, there are two categories of power assisted bicycles that may be used legally on our roads:</p><ul><li>power assisted bicycles with up to 200 Watts of power (the power is controlled by a throttle or accelerator); or<li>power assisted bicycles with no more than 250 Watts of continuous power which meet the definition of a pedalec (the power is controlled by the ride using the pedals).</ul>What is a pedelec?<p>In order to be a pedelec (legal for use on our roads), the power assisted bicycle must comply with the European Committee for Standardization EN 15194:2009 or EN 15194:2009+A1:2011 Cycles - Electrically power assisted cycles - EPAC Bicycle ('EN 15194') and this includes the following.</p><ul><li>It must be certified by the manufacturer and labelled as complying with EN 15194. The label must have the manufacturer's name, the motor's cut off speed in km/h and its electric motor motor maximum continuous rated power in Watts. The label is often found on the bicycle's frame immediately adjacent to the crank.<li>The motor must be electric.<li>The maximum continuous power output of the motor cannot exceed 250 watts.<li>The rider must pedal to access the power (the motor may operate without pedalling up to a speed of 6 km/h).<li>The power must cut out when the pedalec reaches 25 km/h or sooner (if the operator stops pedalling).</ul>Road rules for power assisted bicycles<p>Riders do not require a driver's licence, motor vehicle registration or compulsory third party insurance. Riders are bound by the same rules as for other bicycles, including the need for:</p><ul><li>the rider to wear a helmet<li>effective brakes<li>a bell, or other audible warning device<li>a rear-facing red reflector at night<li>a white light to the front and a red light to the rear at night (both may flash) clearly visible from at least 200 metres.</ul>Differences between a power assisted bicycle and a motorcycle<p>A power assisted bicycle is a bicycle with a motor attached to assist the rider. At first glance some motorbikes with pedals look very similar to power assisted bicycle. The main differences are speed, pedal crank spacing, weight, seat position, seat shape and gearing</p><p>A good rule of thumb for deciding if the pedals are the main power source is:</p><ul><li>if the distance between the inner faces of the cranks is less than 180 mm<li>whether it can easily be ridden without power assistance (you should be able to ride it home if the assistance motor fails)</ul><p>If these apply and the motor output is either 200 Watts (or less) or 250 Watts (and meets the definition of a pedelec), then it is a power assisted bicycle.</p><p>If the main source of power is the motor then it is a motor vehicle and operating it requires a driver's licence, registration and compulsory third party insurance. However, few, if any, of these vehicles are able to be registered because they are not capable of meeting registration requirements, such as compliance with the Australian Design Rules. Such vehicles cannot be legally operated on our roads. </p>
Wow, you have some really loose regulations in IL! I wish I lived there.<br><br>In the UK, you cannot have a bike that has more than 250w of power, it must have pedals, and it cannot exceed 15.5mph on full-electric.<br><br>Anything more than that, or anything with petrol at all, is considered a motorbike and you have to have documentation, helmets, etc. etc.<br><br>Talk about fun-police! Thanks for the comment though, always nice to learn about how the laws differ and such :)<br>
<p>I never would have thought the UK would have such tight/strict laws on motorized bikes. My original thinking is that the governments would be more in favor of small-engine vehicles, especially in Europe, where (correct me if I'm wrong) most personal transportation is done by way of bicycles, motorcycles, and small cars. Here in the US, many of us use larger vehicles (with larger engines) for personal transportation. Please note that this post is not about the environmental effects of using large engines, nor is it about how America is somehow worse/better. It is just very surprising that this would be considered illegal in any logically thinking country/state. My theory is that they are using the &quot;safety factor&quot; as an excuse to completely hand-over the market to businesses making money on mopeds or other small vehicles.<br><br>The sad facts, as I see them, are:<br>-If someone wants to have a moped they will buy a legal, factory-built moped, these DIY projects and cheap kits, although great learning experiences, are not as practical as the real deal. Yes, they will get you around, but they don't have the engineered-reliability of a factory built vehicle.</p><p>-The governments are being sacred into making these laws because A) there is no good way to tax these homemade motorbikes. B) Crazy, and not to mention stupid, people are misusing the power afforded by attaching a motor to a bicycle. The news/media takes their stories and scares the crap out of easily-impressed/simple-minded voters (or law makers) who decide on these laws. and C) These vehicles are somehow always &quot;less-safe&quot; than their factory built counterparts due to the idiots who &quot;think&quot; they can build one safely.</p><p>I feel sorry for the poor police who have to enforce these laws. They are just doing their job, but are required to give you a ticket if they find you don't meet the government's specifications.</p><p>The good news, is um... well... their isn't much. Most laws in effect are put in place due to accidents (caused by idiots) which provide hard evidence for the courts. Not much is being done to stop these laws from taking effect, because we, the riders don't have much solid evidence for our case. The responsible riders are being mistaken for the idiots who caused these laws. And at the moment, DIY motorized biking is more fun than it is practical. However, such vehicles, when used responsibly, are great for learning how an engine works, they will take up less parking space, can reduce traffic and emissions, and will even help to recycle. I'm not saying everyone should be driving one, but don't ruin it for those who do! If you are safe about what you do with it and respectful of others when using it (following road/traffic regulations, not blocking faster vehicles, attaching an appropriate muffler, etc.), you can make worlds of a difference in the way people view these vehicles and you!</p><p>FYI, here in Michigan, I believe we are currently allowed up to a 100cc engine (probably to account for all the hills), but still may not have a gear-shift or be capable of traveling greater than 30 mph on level ground (Look up: &quot;Michigan Vehicle Code Act 300 of 1949&quot; for more information).</p>
<p><em>*always nice to learn about how the laws differ and such*</em></p><p>That's what Instructables is all about, LEARNING! :) </p>
<p>ContraptionMaker, thanks for sharing your creation with us. I've been trying to figure out how to make a similar motor mount. I was thinking the rear support bars would need to be on opposite sides of the wheel, I've been working for weeks on this but it never works (the spindle keeps riding off the wheel). You have brought forth a great new idea, place the mounts only on the left side and have the rear support act as a guide rail for the clutch action. Out of the box thinking for the win!</p><p>As for troll-people like solsmac, they do not understand. This guy probably doesn't ride long-distances, and thinks his muscles are made of titanium. You will probably never get to race him and his pedal power, but if you did, my money's on the 2-stroke! </p><p>True, this project is not going to change the world. But I'm sure it has already made your life better.</p>
<p>Yes it has. I love to ride but my knees can't take the peddling anymore. I hope you do a structable on your bike. I'm glad I could inspire you. </p>
<p>Interesting, but I bet it's noisy on the road. My ears ring after 20 minutes using the weed eater or chainsaw. Buzzzzzz</p>
<p><a href="http://www.instructables.com/member/Rarnd/" rel="nofollow">Rarnd</a>, You only need a drivers license ,license plate... If its above 50cc's, but not sure if you need a helmet i assume it depends on the state you live in.</p><p>Just though id clear that up.</p>
This is awesome great clutch design I think I might attempt this
<p>Glad I could inspire you, hope you'll create an Instructable, can't wait to see your progress and what you do with it.</p>
<p>I love that you can just get up and go, you don't have to jump off and mess with a pull cord. (BTW can i say i hate pull cords!)</p>
<p>HaHa! Me too!</p>
That's pretty awesome
Like your bike dude. Does it ride smoothly.
<p>Thanks, glad you like it. It rides very smoothly. It's just like riding the bike without the motor, just faster, and best of all, very little peddling!</p>
love the old solex bikes we have here, rode one a while back. Those are just awesome! Bit odd in the beginning, always riding full throttle and no clutch....
<p>Ya, that sounds a little dangerous... </p>
<p>Wow, super cool! :)</p>
<p>Thank you!</p>
<p>Thats a great project looks like a pile of fun. If you go for the four stroke, the six to one gear box in the photo will bolt straight on to a 35cc Honda. </p><p><a href="http://www.scooterpartsrus.com/49cc_gear_box.htm" rel="nofollow">http://www.scooterpartsrus.com/49cc_gear_box.htm</a></p>
<p>Thanks for the info. Think I'm going for a belt drive with the 4-stoke.</p>
You can also convert it to propane. I do all my lawn mower a this way. good plans liked it alot....
http://www.gomeyer.com/rc-cars-scooters/goped-clutch-kit-54mm-p-435.html this is what you want.
<p>Thanks, glad you like it!</p>
But it's still cool!
All I'm saying is I can make a bike that's 1000000000000mpg it's called pedals... Just saying
<p>solsmac, we all know you are trolling. Please post a productive comment! It doesn't necessarily need to be in favor of the project, but at least provide a valid argument. If you are serious and you'd rather pedal, then go ahead and try to eat enough calories to get to &quot;1000000000000mpg&quot;, it's impossible, (Just saying). Instructables.com is not a place for trolling, it is a digital library of ideas and ingenuity. Nobody here enjoys reading idle comments with nothing new to add.</p>
I think he was trying to say bicycling gives you infinite mpg, since it uses no petrol. There is a cost associated with it though; a 10 mile ride at 15mph would burn roughly 520 calories. Based on a weekly food cost of &pound;15 and a daily intake of 2200 calories, that trip would cost you &pound;0.51 in terms of food.<br><br>Petrol being roughly &pound;1.32/litre means the for cost of biking equates to 0.39 litres of petrol, and so 117mpg... so this bike would actually be more economical to ride than biking manually, not to mention faster!
<p>Thank you Shadow, that explains it perfectly! Kudos!</p>
<p>Hey, I've got those! If I had some new knees I could use them! LOL</p>
<p>wait a minute, how do you start it? my weed whacker and a pull rope to start it and it doesn't look like to me that that is how you are starting your motor. It seem to me you are starting in more like how you would push start a manual car: get the bike up to some kind of speed, &quot;pop the clutch&quot; and the engagement of the clutch wheel against the tire spins the motor and starts it that way. Is that what is happening?</p>
<p>Yes that is exactly what is happening. I only need to get to about 5 mph. I pull the lever, the motor spins against the wheel, and it starts. No pull start required. </p>

About This Instructable


874 favorites


Bio: I love to build things. My love affair with destructing, constructing and reconstructing stuff began when I was very young. When I got a new ... More »
More by ContraptionMaker: Bench Power from ATX PSU Thanks to Matthew Bicicleta de 130 mpg (55 kml) 130 MPG BICYCLE
Add instructable to: