50cc w/2 speed Gear box?

silvaire

New Member
Jan 25, 2009
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North of the Golden Gate
That's a very interesting engine you happened to see, and seems like one worth giving some thought to.

It is obviously a Honda Cub based clone engine, of which there are many.

What's particularly interesting about this engine is that in place of a kick start shaft, there is now a cottered pedal crank. I really wish there was a picture of the other side of the engine! If my memory is correct on this, the kick starter shaft on these little Honda engines is just a plain (or maybe bushed) bore in the case and cover. Being almost certainly Chinese made, I doubt this engine would have improved this to ball bearings, and wouldn't likely hold up to any serious pedaling. Probably good enough to start the engine and be legal though!

With a 2 speed automatic and some sort of a high/low box as well, this certainly sounds promising for a motorized bicycle application.


Edit:
From this vendor, I see that $299 plus $40 shipping gets you a totally bare engine with no carb/intake/filter or exhaust etc. If anyone happens to find a cheaper source for this engine and/or one that is more complete, please post a link.
 
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wheelbender6

Well-Known Member
Sep 4, 2008
3,961
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TX
I had considered sticking one of those cub pedal motors in a Kikker Bobber. Should bolt right up.
 
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BarelyAWake

New Member
Jul 21, 2009
7,206
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Maine
That's a very interesting engine you happened to see, and seems like one worth giving some thought to.

It is obviously a Honda Cub based clone engine, of which there are many.

What's particularly interesting about this engine is that in place of a kick start shaft, there is now a cottered pedal crank. I really wish there was a picture of the other side of the engine! If my memory is correct on this, the kick starter shaft on these little Honda engines is just a plain (or maybe bushed) bore in the case and cover. Being almost certainly Chinese made, I doubt this engine would have improved this to ball bearings, and wouldn't likely hold up to any serious pedaling. Probably good enough to start the engine and be legal though!

With a 2 speed automatic and some sort of a high/low box as well, this certainly sounds promising for a motorized bicycle application.


Edit:
From this vendor, I see that $299 plus $40 shipping gets you a totally bare engine with no carb/intake/filter or exhaust etc. If anyone happens to find a cheaper source for this engine and/or one that is more complete, please post a link.
The Honda CRF50/XR50 etc. horizontal clones are really common, this one only somewhat different with the inclusion of the pedal system - I really doubt that's a shoddy modification however & suspect it's far more likely to be simply another clone of a four stroke moped, of which only seem uncommon stateside.

As for the durability & pricing, it's something to consider that it's complete with an actual transmission built for a 'ped instead of some costly aftermarket conversion made with bicycle parts... that alone makes the difference between something like this and even the cheapest of two stroke kits, throw in it's a four stroke w/electric start for some icing on the cake lol

I'm not defending or vouching any particular vendor, although I would suggest calling and asking what's included as the Lifan CRF50 clone (3sp autoclutch) I ordered was pictured the same but included the carb etc., everything but the electricals (CDI reg/rec etc). The moped/pedal case type is somewhat uncommon but this engine class isn't and the price seem pretty much right, even if ya hadta pick up a carby or whatever.

I just think this is a great engine type for our application, reasonably priced & reliable I'd like to see more try it. This is nothing like the in-frame two stroke "quality" yet it's roughly the same cost overall and yet an even better selection of aftermarket goodies - the only real issue is it's somewhat wide & horizontal, a difficult build for anything other than a chopper or recumbent.

Here's my Lifan CRF50 clone 3sp autoclutch build if you're interested;

engine start: http://youtu.be/aQXKnt9hZzU
build & run: http://youtu.be/bNLTLRx8sTI

...and a somewhat dated thread about the horizontal fours, including some chopper build links;
http://motorbicycling.com/showthread.php?t=19630
 

16v4nrbrgr

Active Member
Mar 17, 2012
1,728
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North Bay
It's the same engine as in the SSR moped. You gotta stop to change gears, so if you see a big hill, stop at the bottom and change it into low so you don't have to try a hill start with the centrifugal clutch.
 

16v4nrbrgr

Active Member
Mar 17, 2012
1,728
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North Bay
I read somewhere you can upgrade that motor to shift on the fly, but I think it involves getting the bottom end from a 4 speed semi-auto and swapping out the guts, not sure if it keeps the pedal crank axle in place. A dealer for SSR moped offered the upgrade for $300, the price of a whole Lifan 4 speed 125cc. :/
 

LR Jerry

Well-Known Member
Dec 19, 2011
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Rockwood, TN
The guy at TBoltUSA told me he's heard of people hooking a cable up to the gear switch so You can shift on the fly. He also has a kit to upgrade the cc size. He told me to look up Laser mopeds for tech information. Here is what I found.

LAZER 5 SPECS:

Engine Type: 49cc Single Cylinder

Stroke: Four-Stroke / Displacement: 49ml

Compression 10:1 / Bore x Stroke: 39mmx41.4mm

Cooling System: Air-Cooled

Fuel System: 90# Gasoline

Gearbox: Transmission Ratio: Primary :3.722 1th:2.615(34:13) 2th:1.611(29:18)

Driveline: Constant Mesh, Two Stage Transmission

Human Propulsion with Pedal

Starting System: Electric / Pedal Start

Ignition: CDI

Max Speed: 32MPH (Depending on Riders Weight and Road Conditions)

Max Torque: 2.0Nm

Battery: 12V-4Ah

Fuel Capacity: 2.8L

Brakes: Front Disc / Rear: Drum Brake

Brake Operation: Handle Operation (Front/Rear Wheel )

Front Tire: 2.25-17 with DOT Mark / Rear Tire: 2.50-17

Clutch: Auto

Weight Capacity: 330lbs( Driver Included)

Net Weight: 168lbs

Wheelbase: 47inches / Seat Height: 31inches

Overall Height: 41inches / Overall Length: 72inches / Overall Width: 30inches

Ground Clearance: 4.7inches

Parts / Accessories

Tool Kit: Including 12-14 Wrench, 8-10 Wrench, Socket Wrench, Screwdriver, 5mm Hexagonal Wrench

I also called a moped dealer. He said you have to stop to flip the switch on the engine. He said since the operator can't shift gears on the fly it can be sold as a moped instead of a motor driven cycle. He said the lower gear is there for a passenger or steep hills.
 

16v4nrbrgr

Active Member
Mar 17, 2012
1,728
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North Bay
That sounds like a pretty promising modification with the cable shifter Jerry! I wonder what type of dogring or syncromesh selects the gears, it might be the same type of dogring used in the constant mesh manual and semi-autos, if so it's pretty robust. I think you'd want to use a push-pull cable hooked up to a lever on a pivot to make sure that you have good feel of what's going on inside, rather than a pull cable with a spring and detents. Maybe I should build myself another moped with one of these someday, I like the Honda horizontal 4-strokes, they haven't changed the basic design for forty years for good reason, its awesome! You can put a 88cc big bore kit on that engine for more umph too.
 
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