Project: motorize a bicycle

[nubc]

What are some good bikes with adequate space and geometry to accomodate a 48cc or 49cc 4-stroke motor conversion kit? I'm familiar with the popular 26" Beach Cruiser. I guess it would be ideal to have a stock telescoping front fork. I need a straight seat tube so I can use Schwinn accessories like carrying rack and saddlebags. Caliper brakes, front and back, would be nice. Please share your experiences and thoughts. Except for the white color (black preferred), I could be content with the Huffy Cranbrook Beach Cruiser @ $89. But is such an inexpensive bike necessarily of cheap construction? What's your take?

Example of a base bicycle that is not a Beach Cruiser
https://www.youtube.com/watch?v=6wS6LtGvmfA

[nubc]

How To Install a 48cc 4-Stroke Engine Kit on your Bicycle by BikeBerrycom
https://www.youtube.com/watch?v=5ADjEgJnE2I

1 How To Build 4 Stroke Motorized Bicycle Part 1 Unboxing Prepping Frame
https://www.youtube.com/watch?v=f23aVgmXTJk

2 How To Build 4 Stroke Motorized Bicycle Part 2 - Install 3 Piece Crank & Motor Mount
https://www.youtube.com/watch?v=shU2aOYa3sQ

3 How To Build 4 Stroke Motorized Bicycle Part 3 - Transmission & Chain
https://www.youtube.com/watch?v=BxjY3wl9TQ4

4 How To Build 4 Stroke Motorized Bicycle Part 4 - Final Assembly & Starting
https://www.youtube.com/watch?v=Vl031xJEI9c

How To Install A Motorized Bike Engine (4-stroke)
https://www.youtube.com/watch?v=4s1_fUdxM3o

How to Install Ghost Racer 7G 49cc 4-Stroke Bicycle Engine Kit from GASBIKE.NET
https://www.youtube.com/watch?v=adlj2zPBIaQ

[drunkjedi]

Hi nubc,

I don't know much about these kits.
But I have seen electrical kits.
May be try that too.

[nubc]

Electric converter kits seem considerably more expensive (almost 2x), especially considering the battery, which is the most expensive component. Battery is typically operable for an hour only, before recharging is required.

It just so happens that 49cc is about the max power motor that these ordinary bikes can handle without risking catastrophic stresses on welds, kit connectors, etc. Coincidentally, local statutes allow a motorized bike to use the road freely without requiring license, tag, registration, insurance, etc on the part of the rider provided the size of the motor is less than 50cc, and top speed on a flat surface does not exceed 30 mph. I don't know whether such an exemption exists for a battery powered bike. Gas mileage is 75 to 120 mpg. The 4-stroke motor can be run continuously for a much longer period than the 2-stroke.

Motorized Bikes 2-Strokes VS. 4-Strokes (discussion starts 5:50)
https://www.youtube.com/watch?v=xTgvvLr4VZY

[technosaurus]

My brother has used old weed eaters and chainsaws to drive the wheels using an appropriate sized roller on the drive shaft that rested on the tire. IIRC he mounted it on a pivot so that gravity put enough force on the wheel and he could just pull it up to immediately remove power. He found that if you try to drive it directly using sprockets, it starts shaking at higher speeds (the mounts weren't perfectly engineered).

He also tried battery powered drills, but needed longer distance. You could always add extra batteries and use a motor from an electric weed eater or lawn mower though.

Point being, you don't _need_ a kit, people put everything you need on the curb. Its more fun too.

[nubc]

A new Huffy 26" Cranbrook Cruiser is $90. A new kit for 2-stroke motor is $100 to $150. Personally, I'm only interested in 4-stroke motor: quieter, more reliable, but the kit will be more expensive because it's a more complicated motor. I don't want reinvent the wheel. The kit is plenty of challenge for me.
Generally, top speed is nominally 20 to 25 mph. Not trying to go real fast, just respect limitations of device. These bikes reportedly break down at high speeds. Not my thing, anyway. Local statutes specify that the top speed on a flat surface cannot exceed 30 mph. Anything faster is deemed a motorcycle and subject to regulation.

[nubc]

These kits are far from perfect. The most tedious part of installing the kit is the rear sprocket assembly, which often takes hours to install. Not only is it difficult to install and center, the arrangement is functionally and structurally unsound because the sprocket is being attached to the spokes on one side. There is a better solution designed by Manic Mechanic, in which a connecting adapter is attached to the rear hub, and a high quality sprocket is attached to this adapter, all for under $100. User has to select the number of teeth in the sprocket, the gear ratio. For power, so rider does little pedaling to assist the engine, 48 teeth could be selected, but this gear ratio gives a top speed of only 21 mph. The 44-tooth gear does not provide the extra power at low speed, but it does give an optimal top speed of 28 to 30 mph. The Manic Mechanic hub-attached adapter and sprocket installs in 5 to 10 minutes, is centered as installed on the rear hub, plus the hub adapter gives lateral adjustment of 5/8 inch so the rear sprocket can be more precisely aligned with the power sprocket on the motor.

How To Install A Motorized Bike Kit - Rear Sprocket
https://www.youtube.com/watch?v=-fiUTJ6a0Aw

[Moat]

Have you looked into any direct friction (roller) drive kits?

Back in the 70's, I owned two Solex 3800's, which used an abrasive-embedded (carborundum, I think) roller. Tire wear actually wasn't much of an issue, as I recall, using the OEM Solex tires - which had a few heavier, flat-topped ribs on the tread that the roller rode against. Very simple, straightforward and reliable drive system (especially since it was directly driven off of the crankshaft end on the slow-turning, low-output, 2500-ish RPM Solex 2-stroke engine - no reduction drive/gears/belts/chains/etc).

The Solex was an absolute bulletproof gem of a moped! Ridden year after year WFO everywhere (@ ~22 mph), with no issues. And 180 mpg! A fantastic design - I've always wished someone manufactured a quality, bolt-on kit based on that engine/drive unit. Wheel diameter has no effect on "gearing" with roller drive, either.

Bob

[rockedge]

my step son wrote software for the Copenhagen Wheel
https://www.superpedestrian.com/

not so easy to convert a bike to power but I would like to see some home brewed solutions!

[WIckedWitch]

The most eco-friendly way to power a bicycle is called "pedalling".

[Mike Walsh]

My brother has used old weed eaters and chainsaws to drive the wheels using an appropriate sized roller on the drive shaft that rested on the tire. IIRC he mounted it on a pivot so that gravity put enough force on the wheel and he could just pull it up to immediately remove power.

Which is exactly how the French Velo-Solex motorized 'bicyclette' has worked for decades. Only downside with this is that because they're transferring drive directly to the rubber of the tyre by friction, it tends to shorten the life of the tyre (wears out the treads rather quickly.)

To be fair, though, Moat's right. The tyre as supplied for the front wheel was of heavier construction, so wear wouldn't have been such an issue. But yes; 180-200 mpg was perfectly possible. At one time, the streets of Paris were knee-deep in the things..! They were extremely popular with the French....

The motor is pivoted on the front headstock, with a prominent handle for lifting it/lowering it, along with a ratchet catch (or simple hook, I was never sure which it was) to hold it in the upper position. They didn't even bother with a starter; you just dropped the engine onto the wheel, and pedalled away till it fired up...







But's it's certainly one of the easiest solutions. They haven't been made for over 30-odd years, finally shutting up shop sometime in the '80s, but there's still tens of thousands of them around. They're so simple all you need to maintain 'em is a pair of pliers.....and a couple of screwdrivers.

------------------------------------------------------------

The British two-wheel 'scene' was rife with these sort of things in the immediate post-war rationing years. Maximising 'bang for your buck' was definitely top priority in those days...

One of my all-time favourites for oddity (and rarity) value has to be the BSA 'WingedWheel'. This thing was built-in to the hub of a standard bicycle wheel, albeit constructed with somewhat stronger spokes than usual! You bought the entire thing as is, and just bolted it straight in; the asking price at the time was somewhere around the £15 mark (remember, we're talking 65 years ago. The current-day equivalent would be at least a few hundred...)





They were quite commonly-seen adorning the two-wheeler of anybody who lived in hilly areas, and relied on their cycle to get around for their work; especially district nurses, and the clergy!

But the oddest of the lot had to be the Wall 'Auto-wheel'. This thing, again, was bought with a complete cycle wheel, although it was a smaller size, with sidevalve engine attached (with external flywheel!), built-in fender, with fuel tank on top, often a rear light, and attachment bracket(s). You bolted the thing onto one side of your rear wheel spindle, and attached articulated stabilizer brackets to keep it steady, while at the same time allowing it to move up and down with the road surface, so as to maintain traction...





Possibly the most conventional of all, and the closest to what nubc wants to achieve, was the Ducati 'Cucciolo', or 'Little Pup'. It was designed to fit into the bottom bracket of the frame, just above the pedal-set, and drive through the normal chain drive to the rear wheel.....and it was, indeed, 4-stroke, as opposed to 2-stroke, achieving valve operation through the ingenious use of 'pull-rods' as opposed to the more conventional 'push-rods'.





So it's hardly a 'new' idea. The very earliest example is an engraving of a contraption cobbled together by a French 'inventor' back in the early 19th century (1818, in fact), and showed a 'velocipede' with an attached steam-engine!

Imagine trying to balance that....


Mike.

[WIckedWitch]

I once saw a sad-looking VeloSolex with a seat tube but no saddle. At the time I was in the company of a Dutch colleague who suggested that it was a symbolic metaphor for Wagner's Ring Cycle.

[Mike Walsh]

I once saw a sad-looking VeloSolex with a seat tube but no saddle. At the time I was in the company of a Dutch colleague who suggested that it was a symbolic metaphor for Wagner's Ring Cycle.

^^^ Hah!.

The Dutch themselves are something of a 'bike-mad' nation. It's not in the least bit surprising that there's a fair number of VeloSolexes kicking around the back alleyways of most Dutch towns & cities, too.....


Mike.

[Moat]

Hi Mike -

The motor is pivoted on the front headstock, with a prominent handle for lifting it/lowering it, along with a ratchet catch (or simple hook, I was never sure which it was) to hold it in the upper position.

Yes - it was a stamped steel lever that caught a hook on the steering stem (though the final models had a cam/lever lift arrangement down on the side of the engine). Pull the lever back, flex slightly to the side, and drop the engine onto the tire. A thumb lever on the LH grip activated a small compression release poppet valve in the cylinder head, facilitating easier pedal starting... press the release, pedal a few yards and release - off she'd go.

Simple centrifugal clutch built into the roller drive assy, so as you'd not burn a divot into the tire while idling at a stop.

Fuel tank held ~1.5 quarts, and the fuel cap underside was a cup for measuring the proper amount of oil to add to a full tank. Fill the tank, add a cap of oil and waggle the bars a few times to mix it up - good for another ~70 miles!

Solex's were sold in the millions over so many years, they were very well sorted - well-built, reliable, simple and easy to maintain. Wonderful little vehicle! I always pined for the smaller-wheeled 5000 model, but never saw any over here.

The manufacturing rights passed through numerous hands through the 80's/90's/2000's, manufactured in different places, and were sold here in the U.S. up until just a few years ago as the VeloCruz - http://www.velocruz.com/home.htm (at least I think they are no longer available...). Apparently none of the later offerings were quite as well built as the original French Motobecane versions, using a number of cost-cutting, outsourced (Chinese) components that just didn't hold up as well. A real shame - they were simply brilliant little machines!

Bob

[Mike Walsh]

Hi, Bob.

Thanks for clarifying that about the hook & handle. My own experiences with Solexes go back a lot of years, to when I was a teenager.

My old chap was a boating man, and progressed up through sailing boats and a motor sailer to a full-blooded 52' powerboat, which he had built for him by a local boatyard; A.V.Robertsons of Woodbridge, on the Suffolk coast. Based on the then current semi-deep vee planing hull as used by the UK pilots and Customs & Excise, it could do 19 knots at full chat with its twin 300 bhp Ford Sabre diesels, and with the over-large tanks he'd had fitted, was good for a range of around 1400 nautical miles on a single fill-up.

But, I digress.....

We used to go all round Europe during the holidays, with France, Belgium and the 'Low Countries' being regular ports of call. On one occasion, we'd gone down the west coast of France, and during a sudden storm in the Bay of Biscay, ran for cover in a small port not far from Bordeaux. We were stuck there for nearly 3 days; this monster showing no signs of abating for quite a while (not uncommon down there).

During that time my parents struck up what proved to be a long-lasting friendship with a local couple; we 'exchanged' with them, and stayed in touch for many years. Their son, Michelle, a couple of years older than me, was at the time around 14; the French permit their youth to ride cyclemotors from that young age, or did in those days.

He'd got an old VeloSolex, which, as kids do, we spent a lot of time just 'messing around' with.....but at that time, I wasn't as interested in 'technical' stuff as I later became. I clearly recalled the starting method, but couldn't remember how the engine was secured when at rest, so.....thanks for jogging my memory.

We old farts have to help each other out in such ways..!

(I was interested to see that the earlier models actually had the headlight built-in to the engine casings; I'd forgotten about that. Remind me, would you; how did you kill the engine? I seem to recall a 'spring tag' which you pressed onto the top of the plug lead, which shorted it out.....but I could, of course, be wrong about that. It was a lot of years ago.)

BTW, thanks for the VeloCruz link; nice one!


Mike.

[Moat]

Mike - a long time ago for me, as well - '74 or so - so a bit foggy on killing the engine, but I don't recall an ignition kill switch of any kind... I believe you just thumbed the decompression lever. The plug was hidden under the skull cap on top of the head, along with a little disc-shaped air filter - no plug grounding tab in there (tho I've seen many old lawnmower engines with such a kill tab). The older Solex's may have had the tab, though.

And yup, my '73-'74 3800's had the rectangular headlight built into the front plastic engine cover. Oh so elegant, with the optional chromed engine guard surrounding it. Delivered a lot of newspapers to afford that kinda' class!

Sorry, nubc - kinda' hijacked your thread here...

Bob

[nubc]

Bad news from the DMV
https://www.ncdot.gov/dmv/vehicle/title ... edfaq.html
It's really hard to find a real retail moped locally. Since I would want all the safety features like two mirrors, turn signals fore and aft with good separation, I have started looking at 50cc scooters which have those features as stock equipment. One issue with low-end scooters is the shorter wheelbase, 45 to 48 inches, which means my knees could make contact with the handlebars during operation. A wheelbase of 50+ inches is much better. So right now I'm looking at Honda Ruckus and Yamaha Zuma 50. I also like the Yamaha C3, modeled on a Cushman, but the C3 was discontinued in 2013. The salesman at the local dealership told me that it's illegal for a moped to operate on any road with a speed limit higher than the spec (limiter in operation) top speed of 35 mph, for instance, the 45 mph road. If that is truly the case, I might have to forget about 50cc mopeds and scooters. And I guess a 125cc is the next step up, which is technically a motorcycle.

[Moat]

Hi nubc - FWIW;

I own a 2013 Zuma 50f (the later, 4-stroke model - essentially a C3 with different bodywork), and it's a great scooter - if not particularly fast (acceleration, especially - but I'm slowly working on improving that with removal of the variator's restrictor washer and playing around with roller/slider weights...). Top speed of ~40 mph (GPS), 126 mpg average so far, bullet-proof reliability, generous underseat storage, instant starting being it's fuel injected, quiet and smooth. I'm only 5'-6" tall, and found the step in the seat too far forward, so have done some cutting back of the seat foam to make it more comfy (stretch the arms and legs out a bit).

It is missing the C3's kick starter, though - something I will add when money/time permits.

One year of the C3's had a crankshaft/connecting rod recall from what I remember (maybe 2007?) - if looking to buy one, make sure the recall has been addressed.

The pre-2012 2-stroke Zuma 50's are great scooters, too - generally faster accelerating than the C3 and 2012-on 4-stroke Zumas, but of course noisier/smellier/poorer gas mileage and slightly more maintenance intensive (as any 2-stroke will likely be). But overall very reliable, Yamaha quality. And easy to modify for more performance (not so on the C3/Zuma 50f's) - lots of performance parts available (I believe the engine is based on a very common Minarelli design). Most common complaint being the uncomfortable sloping-forward seat shape.

The Ruckus is an excellent scooter, too - typical reliable-as-a-hammer Honda quality. But a poor front (small drum) brake and without the convenience of an underseat, lockable storage bucket. About the same performance as my 50f, but with a larger aftermarket for performance mods - which are easier, as it's carbureted (instead of injected, like the Zuma 50f/C3).

I think your salesman is FOS on the road/speed limit issue - BUT - the individual states determine such moped laws, so you'd have to do some digging there in order to get a handle on your state's specific restrictions for mopeds. Here in Michigan, we are limited to 30 mph top speed (um... ha ha... ), 100cc's, 2.5 hp (IIRC) and can ride on any road other than limited access highways (i.e. - freeways) - we're just required to stay to the far right in order to let traffic pass easily (same as a bicycle, really). The law here has been essentially that way for many decades, without any major issue.

For a more traditional-style moped, have you looked into the resurrected Tomos? Some really neat 2-stroke models...

http://www.tomos.si/en/

http://www.pgimoto.com/products.html

... although still a bit hard to find in the US.

Or maybe an SSR Lazer...

http://www.ssrmotorsports.com/store/moped/lazer5.php

I also own a cheap Chinese Taotao ATM50 scooter, which actually performs as good or better than my Zuma - but it's tiny, cheaply manufactured, and unless you're willing and able enough to work on it, it'll literally drive you mad chasing the plethora of issues that are typical of this class of scooter (parts are very inexpensive, though). I'm an experienced mechanic and have addressed many/most of my Taotao's issues, and love the little bugger... but can never quite rely on it entirely (it's left me stranded far from home a time or two).

Otherwise, I'd recommend the sweet middle spot of very good Taiwanese/Korean quality/reliability at a lower price point than Honda/Yamaha... Kymco and Lance/SYM - both very good scooter manufacturers at a more reasonable price. The Genuine Buddy/Roughhouse are excellent Taiwanese scooters, too (made by PGO). I particularly like the Lance Cabo, myself...

https://www.lancepowersports.com/models/cabo.html

FWIW!

Bob

[nubc]

Hi Moat,
Some really good suggestions you gave. I like the Laser 5. If only there was a 110cc or 125cc version. Laser's body style is much like the Honda Cross Cub, but with automatic transmission. Reminds me of my Honda S90 which I owned back in 1969. Now that I know that all mopeds must be registered and insured, I am less willing to be limited by a 49cc motor, so I have changed my focus to scooters and motorcycles in the 110 to 150cc range that can do 60 or 65 mph. I found a local shop that sells the Wolf Lucky2, in fact the whole line of Wolf scooters. Honda has reissued a modern version of the Cub series, which I admire, but it's ridiculously expensive at $3600. Actually the Honda Monkey 125cc (another retro!) isn't too bad. I wonder, if I purchased a frugal 125cc vehicle, would I regret not getting a 150cc. I probably don't want anything bigger than 150cc, because I would lose the advantage of fuel economy and quiet operation. A few videos suggest that a 125cc vehicle does 55 mph easily enough, but then struggles a bit to make 60 or 65 mph.I want the freedom to use most public roads, except interstates of course. At the risk of being a wuss, I'd like to get a modest windshield as well.

[Moat]

Yeah, I see now... given the insurance situation in NC (which is, thankfully [!$!], not a requirement in Michigan for mopeds), you're definitely on the right track in eyeing something in the 125-200cc range - much more usable as serious conveyance and safer in traffic.

The Honda PCX 150 and Yamahs Smax 155 are both universally loved/praised, and punch above their displacement in regards to performance - the PCX being the slightly more fuel efficient, at ~100 mpg vs. the Smax's ~75-85 mpg. Outstanding scoots, both! And both have windshields, to boot (with larger aftermarket shields available). Both will fairly easily cruise @ 55-60 mph all day - maybe even 65 comfortably on the slightly more powerful Smax. A b!tch gettin' to the valves on the PCX, though (lots of bodywork) - and a frequent 2500 mi. adjustment interval called for in the service manual (although most folks go longer after the first adjustment or two).

If you really want something that will easily hold (a true) 60-65 mph and have a little in reserve, the Smax would probably be it... but any more than that, and you'll likely have to start looking at the 200cc and up range of scooters/motorcycles (Suzuki Burgman 200, Honda Forza 300, Yamaha Xmax 300 - or any of the new range of smaller motorcycles; Honda CB300, Kaw Versys 300x, Yamaha R3, Kaw Ninja 400, KTM Duke 390, BMW 310, etc.).

The generic Chinese 150cc, air-cooled GY6-powered scooters (like the Wolf you mentioned) just won't do those speeds (not reliably - or for long - anyways).

I too think the new Super Cub is absolutely flippin' gorgeous! A welcome addition to the US market. But I was really, secretly hoping for the Cross Cub (I've owned a CT-90 and CT-110 in the past, and am forever kicking myself for selling 'em! ).

The Monkey is a pure beaut, too (I've often dreamed of a Grom, myself...). Or Kawasaki Z125 Pro. Or how about the more classic-styled Kymco Spade 150? Not quite the fit and finish of the Big 4, but very good quality nonetheless. Any one of those would be a pure blast - but of course, they give up the notable convenience/utility of a twist-and-go CVT transmission and underseat storage of a scooter proper.

Riding 50cc-ish mopeds is definitely a different experience than more "substantial" cycles - keeping to the side of the road, with one eye glued to the rear-view mirror, putting along at 30-35 mph... but I've found it immensely enjoyable in it's own way. Sticking to low-traffic rural backroads, I find I notice many new things that I've passed by a hundred times before without seeing. And it's generally quieter (wind noise) and less fatiguing, less "frantic" (damn... I'm gettin' old, I guess... ). I do really miss railing the "twistier bits", but still own a KLR 250 w/street-ish tires that kinda', sorta' satisfies in that regard...

Bob