Motorized Bicycle

I had been doing some research on getting a motorized bike and the Golden Eagle Bike Engines motorized bicycles, running EHO25 25cc Robin/Subaru Mini 4 engines get about 225 miles per gallon. The similar EHO35 35cc Robin/Subaru Mini-4 gets about 200 MPG. I’ve seem this claim verified in a few places.

These are 1.1 and 1.6 horsepower 4 cycle engines made by Robin Subaru that weigh under 8 lbs… under 13 with mounting hardware. So that’s a 200 lb rider, 25 lb bike, 15 lb engine…

I’m thinking of getting a motorized bicycle because:
– You need a lot of motorcycle to go over the Bay Bridge comfortably…. 250CC, $3-5k used. A motorized bike costs $200 for the bike + $550 for the engine, new. I just saw a used bike and engine on Craigslist for $325.
– You need a lot of nerve to take a motorcycle over the Bay Bridge. Lane splitting is nerve wracking and dangerous. In the 1 month I’ve been here, I saw one bike almost get bowled over by a car that didn’t see the bike and moved into his lane (or he was being a super-duper asshole). And pretty much every lane splitting motorcycle I saw was inches away from disaster.
– I mostly want the motor so I can keep up with slow urban traffic… SF traffic peaks at about 35 mph
– It would be peachy keen if I could easily put a motorized bike on a bike rack hanging off the back of my car.
– It is convenient to combine a bike (that can be run under human power) with a vehicle with more range and speed. Electric bike batteries are too heavy and underpowered.
– A motorized bike compares favorably to a 150CC scooter:

  • top speed: 30mph vs 50mph
  • highway capable: no vs not really
  • weight: 40lbs (can be carried up stairs) vs 200lbs
  • mileage: 200mpg vs 65mpg
  • safety factor in an accident: similar
  • cost (new): $800 vs $2,500
  • towability: bike rack vs trailer
  • can be pedaled effectively: yes vs no
  • passenger capacity: no vs yes
  • hauling capacity: backpack & 1 panier vs backpack & 1-2 cubic foot storage space
  • noise: similar volume (some scooters are very quiet, most scooters make a less annoying noise than a motorized bike)
  • cool factor: novelty vs sleek
  • insurance: free vs $400/year (approx)

A motorized bike wins in most of these categories. So why don’t I see more of them on the street??? Am I missing something?

Beuller? Beuller?

Potential negatives….

  • When riding in traffic lanes, especially at night, cars behind me might not see my (minimal compared to scooter) lights
  • Cars won’t believe a bike can keep up so they’ll want to pass me, regardless of my speed
  • … ?


  1. Luis says:

    Did you ever get the motorized bike? I just bought the kit today and wanted to know how it handeled in S.F. I live in eastbay

  2. Lee says:

    No, I haven’t. It’s a couple little reasons… I worry that car drivers will freak out when they see what looks like a bicycle from behind keeping pace with them down the street and they’ll do stupid things. I kind of ran out of energy for projects. I haven’t found I need a mid-range vehicle as much as I thought; driving & parking in SF isn’t as bad as people let on.

    That’s not to say a motorized bike wouldn’t be totally sweet. It would be good for the world if you blogged your bike building and using process! Tell me how it goes.

  3. james says:

    first off sorry about my spelling. anyways i live in a small city in ontario canada (only about 34000 people live here) and i own a homemade bicycle/moped which took me about 10 hrs to build, and i love it. i drive my motorized bicycle to work everyday. the reason i have one is only 23 and a male so insurance is ridicous ($200 a month no accidents or tickets).
    B.i live in the 3rd floor of my building and didnt want to carry a 80lb moped upstairs everyday (i dont leave it downstairs because things get stolen fast around here
    C.gas prices are ridicously high and getting higher is just a blast to ride. a bike with a engine gets alot of attention because of the fact that they are soo rare

  4. blues39 says:

    I purchased the 40cc Tanaka Engine form Golden Eagle Bike Engines.
    I put it on a Giant mountain bike. I have commuted to work four times on it and love it. My commute is 40 miles round trip.
    My average speed has been 21 mph with top speeds of 30 plus. It runs best at about 26 MPH. I would recommend Golden Eagle Bike Engines to anyone who wants a motorized bike. FUN FUN FUN

  5. luis says:

    I bought the 35cc robin/suburu and I love it. My commute is 12 miles round trip with an average speed of 28 mph. After riding it for a few weeks I average 20 miles per tank and will probably get 130 mpg but I haven’t finished the first gallon yet. I may purchase the trail gear because I have a long incline going home and usually pedal a bit to keep up the speed ( I’m Lazy ). How’s the 40 cc tanaka I really considered purchasing it because the power but didn’t want to mix fuel on a 2 stroke.

    How long does it take you to ride one way? To drive the 6 miles for me it takes 12 min. because of speed limit and stop lights but on the bike it takes me 20. Not to bad.

  6. james says:

    i am consitering buying a golden eagle. ive herd good things about them and wouldent mind paying that extra cash for a good quality engine kit. but to whoever isnt lazy and dosent mind pedaling a bit check out this i was blown away when i saw this new kit. they are around $400 and take 15 min to install. i woulent buy one because it is only 1hp but wow what a cool kit.

  7. Lee says:

    The Revopower won’t be out for a year but it looks pretty cool. I worry about breaking it when hitting bumps but then it might be just fine…

    I’m reconsidering getting a motorized bike. My 90 mile/day commute continues to get more expensive; my carpool buddy Linden moved a few miles further away from me :-( . It’s possible to bike to the train and then ride 5 miles in a flat area to work.

    I’ll look into it this weekend (along with a million other things I’ve got to “look into”). Not enough time in a day I tell you.

    Update 8-25-09: The RevoPower website has gone offline. I guess the idea didn’t fly :-(

  8. blues39 says:

    I have the 40 cc Tanaka engine, which is the 2 cycle. I bought a 2 gallon gas can which i fill up and put in 2 bottles of the 2.6 oz of 2 cycle oil. Its not really a hassle at all. I also have a MSR full bottle that holds 30 oz. of my mixed gas, which i attach to a water bottle holder on my bike for the 20 mile commmute back home. My one way commute takes anywhere from 50 minutes to 60 depending on traffic and lights. My average speed is about 22 mph with lights and traffic. I have a high of 34 mph, but the engine really runs best at about 27-28 mph. The engine has a 33 oz tank which i fill to 30 oz. My gas milage is approx. 26 miles per tank. I think that will give me about 112 miles per gallon. I have about 260 miles on the engine right know, so I think milege might improve. Still very happy with the GEBE product.

  9. james says:

    what gear do u have on the tanaka 40cc? i herd those kits ars very powerfull and can do well over 30 mph with the standard gear, i was just wondering if u have the highway gear.

  10. blues39 says:

    I have just the standard gear #13. I quess i need to check out the Hwy gear. It could be scarey going faster than i am. I’m not sure if i want to go any faster.

  11. blues39 says:

    My bike with engine weighs around 40 lbs plus I weigh 230 lbs. With a lighter rider i’m sure it goes much fater than my top speed of 34 with the standard gear. But again 30 + mph on a bike is really fast.

  12. zach says:

    Why dont you just make one. I made one in about 2 hours, and im only 14. the only thing is that the cops are not so fond of my bike as i am.

  13. Lee says:

    Zach, I need pictures!!

  14. james says:

    making one would be nice but getting the proper ratio on a gear or belt drive is difficult and a roller drive kills your wheels. i do give u grats on making your oun, that is not always a easy task. but yes i would like to see a pic of it as well. i am looking to make one for a friend of mine and need a simple but effective way to do so. im in the process at the moment of looking for a small engine at garage sales, hopefully with a clutch so if anyone has any recomendations of a type of engine (such as one from a weed wacker or something simmiler) it would be appreciated.

  15. jimbo says:

    will someone share their plans and step by step instructions to help me build my own motorbike. how about with a weedeater engine? i’m now in a rural area and i need (and always wanted) a motorbike. any help is deeply appreciated. thank you. jim

  16. zach says:

    as much as i would like to post plans, i will coose not to. this is because every engine is a little different. i will offer advice though. if you are a beginner i would go with friction drive because it is far more simple compared to belt drive and chain drive. friction drive is only practical if you live somewhere that is very dry because even the slightest amount of moisture will cause the spindle to slip against the tire causing severe tire wear and a great loss of speed/power. if you have a larger engine i would say go with chain drive. by larger engine i mean anything greater than 2 horse power. chain drive is best because you can drive it in all conditions, and your tire wont wear down nearly as fast. you can also have a centrifugal clutch with a larger engine. for more information i strongly reccommend the following website.

  17. zach says:

    that stuff is realy expensive and you would have a better time making one yourself.

  18. jimbo says:

    does anyone have a used bike engine and install accessories they will sell me at an affordable price. maybe you upgraded. maybe you just have an extra one you’re not gonna use. whichever, i need a good deal. thanks. jim

  19. james says:

    i think most people have to remember that cheaper isnt a good thing. ive seen alot of reveiws and have came to the conclusion that most people who get cheap engine kits install them, enjoy riding around on them, but waste their money on them because they wind up spending their money on a nice one from golden eagle or station inc in the end. my advice is if you really want a motorized bike for summer transportation to work or whatever then pay the extra money and get the quality kit. if u just want to dink around on it or just like building cool crap out of stuff you can buy at a garage sale and turn it into a motorized bike then go ahead. As for me i enjoy and do both and so i bought a golden eagle kit(suposed to be shipped to me soon) which i will use to go back and forth to work, and im trying to build one for dirt cheap out of stuff i can find at garage sales.

  20. Craig Foster says:

    A few comments: If the purpose of the bike is for dependable serious use as well as fun, my experience is the cheaper motor units while educational from a tinkering perspective are not worth utilizing long term. I live in Dunsmuir, (a small town 6 miles south of Mt. Shasta) and ride regularly down the Klammath River on camping trips and take my bikes up to the top of Everett Memorial Highway, a 4,000 foot vertical climb to the end of the road on Mt. Shasta. My particular favorite is a combination of a recumbent trike with a Honda 50 cc 4 stroke with a Staton gear box/chain drive. California law requires manual propulsion and a combustion engine of 2 brakre horse power or under to be exempeted form the DMV registration requirements Veh. Code 406. I have build motorized tandems both Quadrabent style and traditional, recumbent trikes with solid rear axle as well as split axle with cambered wheels, 2 wheel tandems and a four person bike with twin Hondas for propulsion in addition to people power. I have used the Robin 4 cycle engines (1.6 hp), the Tanaka R series 2 cycle (2.8 hp), Hondas (33) and (50)-4 cycle, and most recently a 2 cycle Mitusubishi. I have also motorized a pedicab with a Honda 50. If I were pressed for one best solution for the serious rider, commuter, camper afficionado or sport enthusiast my ALL AROUND FIRST CHOICE FOR A UTILITY VEHICLE WOULD BE A THREE WHEEL RECUMBENT WITH PANNIERS, AND A BACK PACK WITH A HONDA 50 CC AND CHAIN DRIVE. I have had marvelous results with Staton’s drives. These engines are pricy running approximately $650 for the engine and drive. My oldest Honda has 6,000 miles of very hard mountainous riding carrying 400 lbs and more on three day treks. Unfortunately I account for about 275 of those lbs. The Tanaka 47R is rather loud although there are muffler systems made for them after market, however on a frame like the Giant Stiletto it easily reaches 50-55 mph and has great low end torque. The Subaru 1.6 compares well to the Honda 2 horse if you are a lighter driver. Where the Honda will go up a grade in my area at 22 mph the Subaru travels under identical conditions at 17 mph. The Honda with a sixteen gear sprocket does 34 mph , the Subaru 22-24. mph. The Mitusubishi is a 2 cycle engine with 22.6 cc of displacement. On a recumbent trike with a load of 280 pounds it will go up my test hill at 14-16 mph with peddling assist by the cyclist. It will propel the trike at 18-22 mph on the flat and is a very light weight economical unit. I would recommend this engine for lighter riders and I have not yet road tested it for sustained trips carrying typical loads.

    Side by side tandems with engines are great however, due to the necessity of putting a gear on the rear axle and upgrading the rim and axle components, there is one major drawback-a flat requires disassembly of the Quadrabent kit and about two hours on the road side if you know what you are doing.

    Friction Drives. My experience with friction drives is limited to SUN Bikes USX bike which is a recumbent trike with understeering (no handlebars in front) The handle bars are under the driver’s seat and contain the gear shifts brakes and throttle. The friction drive is the easiest installation. The caveats for friction kits are as follows: The intent is to assist the bicyclist. It will take pressure off your legs going up inclines, it will maintain your speed on the flat. It will not act like a motorcycle wherein you hit the gas and start with positive drive and take off. Problems: It wears the hell out of standard tires which affects the drive friction. It is worthless in wet weather even with the stone wheels. If you have a split rear axle bike you will enjoy a chain drive much more if you are an average enthusiast. You will have to weld your own mounting bracket to accommodate the split rear axle which is offset (about 7 degrees of camber -the chain needs to hit your gear without a twist, thus the motor is mounted with a slight bias).

    Drive gears and number of teeth: There are two parts to this equation: the number of teeth on the gear mounted on the motor and the number of teeth on the drive freewheel. The factors vary as follows: The engine/gear kit combination and reduction through the gear box, the size of the rim and the general terrain. A Staton gear box with a 50 cc engine will typically come with a 16 tooth gear as the drive gear on the engine side. This is true of all the bikes I build. For steeper terrain dropping down to a 15 tooth gear makes a significant difference in the ability for the bikes to be able to handle the hills. The more the discrepancy from the engine gear tooth number to the drive slip gear the greater the low end torque which of course costs you higher end speed. As an example, I have a 4 passenger bike with twin Hondas for drive. The bike weighs approximately 300 pounds. To negotiate the hills I had to gear one Honda with a 13 tooth gear and the other with a 26 tooth gear. The 13 tooth gear drives the bike at 10 miles per hour in solo mode. The 26 tooth gear will not drive the bike at all, however, win they are twined there is a synergistic effect and the governors make up for any cross over power imbalances in conjunction with the slip gears. As geared the bike does 27 mph on the flat, but it requires both engines working together to keep the revs up.

    I hope this information answers some of the more arcane and onscure aspects of your projects.

    Good Luck

    Craig- The Third Wheel Bike Shop

  21. blues39 says:

    If commuting is what you want to do buy Golden Eagle. I have the 40cc Tanaka set up and it runs great. Why tinker with anything else. Buy the kit , install in 30 to 60 minutes and go. I Commute to work 40 miles a day round trip. Top speed in the 30’s. I average 24-25 mph with traffic and stoplights. Why bother with tooth gears!!!!!!!!

  22. zach says:

    STOP BUYING KITS!!!! Use your brains and have fun figuring out how to take common, everyday items and make them into someting you can enjoi. Dont be overwhelmed in thinking that making a motorized bicycle is difficult. It is surprisingly simple. I make a friction drive moped using an old girls bike (that i spraypainted so i wouldnt look like an idiot), a Homelite weedwacker engine, a cheap BMX peg, a door hinge, and assorted bolts and nuts. It is not difficult. you can do it yourself. The best part is….. its cheap!

  23. blues39 says:

    Zach that might work for you but i want realiable trasportation and not look like a hillbilly riding a girls bike.

  24. james says:

    it is like i said before, if u want a dependable ride (which i do) get a kit(and ya i own a golden eagle kit and use it everyday to go to work) And if u want to tinker around and take pride in acomplishing your own goals by building something fun (which i do aswell) make a kit at home. they both have their pros and cons such as, kits cost too much, and, homebuilts are not dependable, but it is all in what you want.
    oh and i was wondering if anyone knows a good place to get engines from. and dose anyone know if any kinds of weed wackers have ceintrificul clutches or can be eaisly fitted with one.

  25. jimbo says:

    i have a LAWNBOY 31CC weedeater that has a centrifugal clutch. it was made that way.

  26. Lee says:

    2 pix of what Zach did:

  27. james says:

    interesting but couldent u have used a larger tire with a to scale larger drive roller?

  28. zach says:

    yea, but i thought this looked cooler.

  29. james says:

    what kind of top speed can you get out of that thing?

  30. zach says:

    aprox 25 mph with a 140 pound person riding it.

  31. blues39 says:


  32. jimbo says:

    how is the foot peg attached to the motor shaft?

  33. Lee says:

    I think Zach’s bike is the coolest deathtrap I’ve seen in a while ;-)

    I can imagine it’s fast with the gearing it has!

    I’d tinker and build something like that right now but I’m working on something right now. :-)

    But I -will- need a bike soon.

  34. zach says:

    i put my feed between the chain stays of the frame. i attached the footpeg to the motor shaft by slipping the peg over the threaded shaft and tightening down a nut that works with the threading. I will worn you, that if you ride a bike like this in an area with many police, you may get yelled at or punished.

  35. Lee says:

    >…get yelled at…


    You never know for sure if something is cool until people tell you shouldn’t be doing it.

  36. scott says:

    zack dose it run all the time or do have something to take the roller of the weel how did u bolt the peg to the shaftmy email if

  37. Coltin says:

    Well I built a motorized bike alot cheaper than any1 on here i bet. I bought the bike for 35 dollars, the 5 Hp Briggs and stratton motor for 20. I Made the Mount for about 50 dollars, and bought the clutch and pullies and sprocket, belt and chain for about 80. And Itll do 45 MPH. Its A great workin bike. I Am currently getting ready to make one with a 10 hp. Well anyway bye

  38. jimbo says:

    any of you guys familiar with a ‘Power Products’ vertical shaft gas engine(unknown cc)made by ‘Phelon’. it’s an oldie ,but,a goodie.

  39. zach says:

    i built a motorized bike for 8 dollars. I win.

  40. james says:

    ok i just got my EHO35 robin golden eagle bike kit and WOW. not as much power as ones me and friends of mine have made in the past but i am just loving this engine. it took about 60 min for me and a friend to install, it is surprisingly light, and it takes normal unleaded gas. i filled it up (with a tank that small it was a little dificult, i spilt about 10% of the gas i pumped) i gave the primer a couple of pumps, pulled the cord ONCE and it started right up. all of my old ones took 10 min to start. i got going on it and at full speed i coulent even notice a hint of vibration and it ran soo quiet. i drove right by a cop and pretended to pedal and he didnt look twice at me (it isnt registered yet so im just trying to keep a low profile untill it is). to anyone who wants a bike engine that they want to drive legaly on the roads i recomment this one.

  41. frank says:

    hi, im interested in knowing how the tanaka 40cc does on hills. i live in vermont and have the 35cc and it struggles on some of the steeper dirt roads. ive used the trail gear too.any suggestions on engines with alot of torque or systems that do.i like the golden eagel system and want to stay with that.

  42. blues39 says:

    I have the 40 cc tanaka engine. I commute to work three days a week.
    I have 3 or 4 very steep hills i climb. If i pedal up the hill I can keep a steady speed of 26-28 mph. Not peddaling it it still will go 22-24 mph.

  43. james says:

    if you want a rediclus amount of power i would recomend the 47cc tanaka from station inc. other than that ive heard good things about the golden eagle 40cc. also if you already have a golden eagle kit with a 78mm clutch you could easly attach any other engine with that clutch size on to toe existing golden eagle clutch. that might save you some money and give you a better variety of engines which you could use.

  44. brandon says:

    ok im not even goin to pretend to know alot about this or anything but the umm shaft that comes out the engine how do you thread it to put the bike peg on there

  45. zach says:

    it is already threaded. go to a hardware store with the engine and find the propor bolt.

  46. shovel says:

    just so anyone, everyone, and their mom knows: it does not matter what size wheel you use with friction drive. the bicycle wheel is not a factor in gear ratio. the speed across the ground will be identical to the speed of contact with the drive roller. Effectively your simplified gear ratio is the engine roller vs. the planet earth.

    also, Zach’s death trap may nor may not be functional and cheap, but it’s a POS death trap anyway and i doubt anyone with the sense to have survived past 18 years old would ride it, much less commute 20+ miles per day as many people are suggesting.

  47. Lee says:

    Sorry, my mom doesn’t read my blog. But I asked her and yeah, you’re right. I just wasn’t thinking.

    Zach’s POS death trap motorized bike runs circles around mine, which only exists in my tiny little head. So I’m not going to criticize it.

    Yours must be frickin awesome. Tell me about it!

  48. shovel says:

    heh, i don’t know about frickin awesome… i gulped hard, ponied up the cash to buy a “golden eagle” and mounted it to a reasonably decent $180 department store mountain bike I already had… and only have to ride it to work about 3 more weeks for it to have completely paid for itself in fuel savings. No broken spokes, no broken belts, no close calls or scary stops, absolutely no problems on a 50 mile daily urban commute (25mi/dir)

    and a LOT less wear on my car, too :)

  49. shovel says:

    oh, and i got the subaru 25cc 4 cycle motor if that matters.

  50. zach says:

    hey shovel, you can suck my dick cuz you pussied out and PAID LOTS OF MONEY for something i can build (POS death trap, my sack).

  51. Lee says:

    Play nice.

  52. shovel says:

    I’m a prototype and display engineer for a global electronics company by trade. This includes fabricating things slightly more complex than a peg on a motor on a bike. This is not a matter of “can”.

    Because I get paid to do what I do best, I also pay other people to do what they do best. This is why any of us have anything, if you’ve ever taken an economics class.

    What I paid for wasn’t a questionable motor that was lying around, loosely bolted with prayer and bubble gum onto a thrift store bike with no brakes … what I paid “lots of money” for was an already engineered, complete solution that is reliable and safe. And summarily better than Zach’s death trap, period.

    Rent on my house costs more than twice what this whole set-up cost, and I have nothing of material value after I pay rent.

    So mr. Zach-the-confrontational, prove to me that you’ve commuted 250 miles per week on the device depicted above for over a month and I may just give you the dick sucking you requested. I’ll be holding my breath.

  53. Lee says:

    Shovel, you were doing really well until the dick sucking part. I’ve disabled comments to allow all parties to cool off.

  54. Lee says:

    Sorry, I forgot about this topic for a while. I’ve re-enabled comments.

  55. Erwin de Leon says:

    So, my question is drivetrain. Which is most reliable, Stanton’s chain drive, or GEBE’s belt/wheel/spoke unit?

  56. Timcycle says:

    OK. Golden Eagle Bike Engines. EH035 Subaru Robin engine. This has been recommended to me. Has anyone used it and what type of pro/cons can you share. I’ll be installing this on a TREK 850.

  57. Eyrcs says:

    I’ve been interested on putting a tanka kit on my bike. I have to ride a bike cause i have no license for awhile. The big question i’ve been trying to find is, can i ride a motorized bike without a license in michigan?… I’ve heard “as long as its under 50cc” , “As long as it has peddals” , “aslong as it doesn’t go any faster than 30mph”… course i’ve heard people just say “no”. Anyone know a site where i can find out or someone on here from MI? I’m pretty athletic and pedal around 18-20mph with no help. I just think it’d be sweet to be able to go that fast when i dont feel like pedaling or even go more than 30 when i do.

    Thanks for any help

  58. Eyrcs says:

    Sorry for spelling.. heh… also wanted to know if anyone has tried the Mitsubishi Rear Mount 43 cc 2.2 hp friction drive kit. Says its very quiet. I seen it from

    Thanks again

  59. Timcycle says:

    Friction drives work good in dry weather. Two cons: They wear down tires and 2. they slip when wet. Don’t know about Michigan. The folks at Golden Eagle Bike Engines are based in Michigan. You might give them a call.

  60. Timcycle says:

    I’ve ordered. Here is my ongoing blog of my experience. The order is now being shipped and I’ll keep everyone updated.

  61. patrick says:

    Is anyone into building electric bicycles

  62. Timcycle says:

    I heard Schwinn just came out with a new one that goes 60 miles on a 10 pound battery.

  63. Windmillcrusader says:

    hey, whatever happened to that kid Zach? That guy seemed to be a tinkerbell with bike parts.
    i’m more interested in something to fart around on, though the eagle kits seem nice, driving one to work seems like i should get my organ donor card upto date before i did so.
    I’ve worked in Trauma Center ICUs before.

  64. jjproctor says:

    you all are crazy but i want to make one to *sigh* i bet im crazyer than all you becouse i want to but a rideing lawnmower moter that is 18HP onto a bick and i did and i went full throutule and it was like 2 fast 2 fureuse im in the hospitile right now wighting this now with 5brocken bones ^_^ it was fun thouh im planing to go again when i get out ;)

  65. jimbeaux says:


  66. Windmillcrusader says:

    eryc, a bike with an engine on it is called a bike. if you get a small engine one, it shouldn’t matter. it goes bike, not motorbike. if you got peddles and a small mounted engine you’re golden.

    one way to find out is to visit the department of motor vehicles in MI to make sure your engine size is under the legal limit. though most would be for sale are legit. otherwise you’d need to get the bike registered, stuff like that.

  67. Windmillcrusader says:

    JJ, that bick you loaded with an 18hp, did it run on butane or methane? sounds like the second one to me.

  68. jjproctor says:

    actually my keyboard is broken so i have to press real hard and well my fingers hurt #_# and it ran on regular gas. it was siting in a dich when i left in the ambulance i dount know if itz still there or not but it was pretty fucked up when i left so i dount know if it runs or not anymore (i hope *i want to ride it again when i get out*)
    and for jimbeaux it was fun i could probably ride from frerica to walmart in 5mins it gos at least 60-70 mph ^_^ itz as fun as it get i could probly out race a cop on the dam thing!!! (i know itz stuped BUT it is fun)

  69. Derek says:

    on zachs model , what is used to increase the speed how do i hook that up to the weedeater engine?

  70. Windmillcrusader says:

    THAT GUY ZACH IS NUTS. I don’t think he’s been back on the list since it go reopened. some guy named jimbo had made some degrading comments about him and then zach got mad. then lee stopped the list for a year. since then, zach has not reappeared. i wrote lee and asked him to contact zach.

    he’s thinking right out of the box on what he does.

    he does not appear to have a throttle, just a kill switch.

  71. jack pontiac says:

    In Alberta Canada you dont need a drivers license,plates or insurance if: the engine is less than 50cc/,it has no manual clutch,it has no transmission.I was pondering the idea of building something with a friction roller type drive.I would use a friction roller that was cone shaped.1.1/4inches on one end and 2.1/2 inches on the other end.I would tilt the motor so that the bottom of the roller is perpendicular to the tire.It would be like a continuous variable speed transmision.To gear up or down,the motor would be shifted side to side so that the rollers varying diameter would correspond to a change in ratio.The police would never notice this. Also,what about a different rubber composition that would compensate for wet conditions that case roller slippage. I still find it hard to beleive that a carborundum roller will slip if wet?

  72. joshua says:

    hi lee i’m only 12 and was wondering if you could email me how to hook a lawn mower engin on to a gear bike with leaving the gears and gear shifter on email me.

  73. Lee says:

    Every project is it’s own. To do something like this, you just have to try it! You should get some help from an adult and go to it! Some of the parts are a little expensive and can be a little dangerous, but nothing you can’t get a handle on with someone with some experience.

    You might try some of the projects at or other sites like it. The tinkering is the thing. And even if you only have a tiny bit of success, your friends will be pretty impressed and you’ll have fun.

  74. jimbeaux says:

    Joshua, you might consider installing a smaller engine 1st. like a weedeater,chainsaw,etc. one of these will be easier to work with and will result in a motor powered bike. you have the ‘spirit’, stay on it and always remember, SAFETY FIRST.

  75. Timcycle says:

    Hi Josh!

    You can see my setup here. The kit can also be purchased separately if you already have an engine.

  76. LawnmowerKing says:

    Hey, everybody… I’ve been messing around in the garage again (oh shit) and in the last 7 hrs. have almost completed my latest ride. I took one of those “green Machine” brushcutters apart, built a nice little aluminum intake, put on an old Mikuni carb, dremeled out the exhaust ports a bit, made up some aluminum bracketry for mounting, and am using some old-style sturmey-archer deraillieurs, wondering if there should be four or 8 speeds…All this over the rear wheel of a cheap $89 Magna mountain bike. I used an ancient Schwinn rear rack (I delivered newspapers with it 30 yrs. ago)for the main mount, those engines already have a centrifugal clutch, so no problem there. Put a cable (used a rear BRAKE cable)and shifters together, and reached the stop point for tonight. There was one I built years ago that made an article in THE OREGONIAN newspaper. Damn thing was clocked at 73 mph at Delta Park in Portland. Got a bit shaky, and had some fun. I’ve also motorized a barstool (McCullough B1 chainsaw engine) but VERY unstable. I used skateboard trucks for the steering, big mistake. I have been doing shit like this since I was 8, so if anyone needs some advice on how to build absurd vehicles, feel free to email me at -Steve

  77. K says:

    I think building on the cheap is cool. At about 14 I was into building motorized bicycles.
    The friction drive wheel was made of wood and about 4″ in diameter. It was then covered with bicycle tire tread and driven through a V-belt reduction system. For the most part, this drive wheel worked without slipping even when wet.
    I have used 1 and 2.5 horsepower 4 stroke engines, for a 18 mph top speed and a 25 mph top speed with good hill climbing ability on the latter. The 1 horse power engine got about 60 mile to the quart of gasoline.
    I made the wooden drive wheels by laminating pine boards with plain white glue, I then mounted this on a 1/2 inch shaft running in cheap turned, not ground ball bearings, worth a out a $1 in todays money. Running the engine allowed me to turn the laminated wooden block round with a screwdriver before mounting the assemble on my bicycle.
    There were many changes to get to success.
    For what is worth 25 mph is fast for a bicycle without springs.
    Good luck to all who build and ride.

  78. Roy Carpenter says:

    Howdy all!

    I just purchased the Golden Eagle Robin Suburu 35cc kit just over a month ago. Before I go any further, I’ll be honest with you-I weigh in at over 300 lbs. I have ridden my Schwinn Alloy Seven cruiser for over 2 years, and quite a lot before getting the Golden Eagle kit. Here’s the bottom line: The Suburu engine is excellent, I move at 30 mph with the street gear on level ground. The Golden Eagle mounting system is well designed, and made, BUT the drive ring causes spokes to break on the rear wheel. Needless to say, that gets old very quickly!! I’ve had four spokes break within the last 5 weeks, and all four spokes were driven spokes which were attached to the drive ring. After breaking 3 spokes, and 3 trips to the truing stand, I replaced my stock rear wheel with a good triple V rim, with 14 guage wheelsmith stainless steel straight spokes, and also took plastic ties, and laced the “driven” spokes to the 18 “non-driven” spokes so that when torque is applied to the drive ring, 36 spokes “give” instead of 18, still thinking that my weight was the real issue. I broke another spoke today. I have to ask myself this: If it’s my 310 lbs that is causing this, why is it always a “driven” spoke that breaks on the rear wheel? And now that “driven”, and “undriven” spokes have been laced together right where the “driven” spokes attach to the drive ring, then my weight would theoreticly be cut in half, (as far as torque on the “driven” spokes, when throttle is applied are concerned), and it would be the same as a 170 lb rider WITHOUT tie wrapping the spokes together so that all 36 spokes are “driven”. The folks at Golden Eagle wanted to sell me a heavy duty back wheel with 12 guage spokes, (which they said they couldn’t order replacement spokes if a spoke breaks, so I’d have to buy a whole new wheel). They were also very quick to say that my weight was the issue, but said nothing of it when I was talking to them about ordering the kit. (I explaintd my weight to them at that time as well). As long as the drive ring slightly bends the spoke forward at the nipple, and releases the spoke to it’s original position, when you let off the gas, then eventually the spoke will break, regardless of it’s guage. I don’t think it is too much to say that the drive ring should be designed so that it engages all 36 spokes, and should mount much closer to the spoke nipple, and rim, instead of practically mid spoke where the spokes are more vulnerable to being pushed forward, then backward, then forward, then backward, and so on. That’s pretty obvious!
    I don’t even know what to do at this point…maybe loose 150 lbs, but I’ll bet ya those spokes will keep breaking anyways. I feel like I wasted $630.oo. Anybody have any suggestions?

  79. Timcycle says:

    Hey Roy. I just sent you an email with some questions. I believe the 35cc of power trying to pull 310 pounds plus the weight of the bike, against gravitational forces is almost too much to ask for a spoke. Your idea of a 36 spoke snap on ring is something GEBE could consider.
    After you get my email, we’ll post the question/answer/ponderings here.

  80. ln217 says:


    I also have broken spokes with the same kit and at 185 lbs. My next break I will replace the rim with a 12 guage spoke rim. I found a forum and under the rack’em up section they discuss these issues and more. Hope it helps anyone reading.

  81. Roy Carpenter says:

    Aha!! I knew I wasn’t the only one having problems….and you only weigh 185? I hate to say this, but I don’t think heavier guage spokes are the solution…they may last a little longer, but they too will break with the “back and fourth” motion of the drive ring. It really don’t look good. :(

  82. jimbeaux says:

    roy, quit protecting your obesity and get out of denial. you’re trying to make a ‘volkswagen’ do the job of a ‘humvee’. you might want to do more ‘walking’ than ‘riding’ for awhile. i hope you can help yourself get to a more healthful way of life. thare’s a lot to enjoy roy, if we can fit through the doors of life.

  83. Timcycle says:

    Hello All. I have the steel spoke rim recommended by Golden Eagle. Nearly 900 miles of all types of road, outracing dogs, rough gravel roads etc… and by God’s Grace, no broken spokes. The steel spokes made the difference. I am approx 170 pounds plus a pack, extra gas canister and water bottle. … Let’s see if we can figure this out. … Roy, I got your email and will now give it a read.

  84. K says:

    For Roy,

    12 gage spokes will be about 4 times stronger than 18 gage. Make sure they are real tight and they will last. If the spokes are loose failure is a sure thing.

  85. Sam says:

    Um, im kinda new to the whole posting a question thing. Im interested in attaching a weed wacker motor to a bicycle, and wish to know more about it. You all seem to know alot, but im pressed for time. I was hoping you could email me suggested procedures/steps/kits/or information to my email at dojixoj@gm[nospam] . Thank you for your time (forgive my spelling)

  86. K says:


    Attach the engine any way you can. My first construction was of wood and electrical conduit.

    The engine you plan to use is most likely about .7 hp at 7,000 rpm. If you use a 1″ drum rubbing on the tire you should get a 10-12 lb. push, with top speed of close to 20 mph, if the tires are pumped up and you have a good tail wind, but probably somewhat less. It still beats pedaling. Good luck.

  87. Wal the Aussie says:

    Hey everybody,type zbox into google and you will get some real good ideas.

  88. leo says:

    where do you put the clutch???

  89. windmillcrusader says:

    Steve, a motorized bars tool? Very kewl.i’m adding you to my palm pilot contact log.

  90. jimbeaux says:

    hey steve, hook a beer cooler to it and come on over! i’ll get the jukebox cranked.

  91. retired tinkerer says:

    about a year ago I built my son a motorized bike using a [verticle shaft] 3.5 briggs and stratton lawnmower engine, although the so called experts on these kind of websites say that it can’t be done. He weighs 250 and it pulls him at about 25mph by the car speedometer. If any 0ne is interested I can describe the measurements and parts used. it is really simple and straightforward, and could be done without any welding if needed

  92. Lee says:

    There sure are a lot of comments on this post! I’ve closed comments on this post but…

    To help the conversation continue smoothly, please post follow-up comments under this new post, Motorized Bicycle – Part 2