| Again, we have arrived at my least favorite season of the year. I leave for work and return home in the dark. Except for a couple of hours on those rare Saturdays when it is not stormy, it is too cold to do anything meaningful outside. And, the winter solstice is still some weeks away, so things are going to get worse. Then winter starts, and it gets really gets cold. I'm not one to claim every passing fad of a disease, but seasonal affective disorder (SAD--a depression caused by a lack of exposure to sunlight) is one that may actually have my name on it. These few months are cold, dark, and miserable and, if I had my druthers, on Halloween I would move to Australia (in the southern hemisphere) and return sometime around Easter. My natural gas bill (think heating) went from the mid thirties to a hundred and teens, and it is still cold in my house. Yuck and double-yuck!!! |
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That being said, I have a new toy. I purchased a bicycle engine ($160), and had it installed on my (lightest and possibly best) bike. I can't recommend my mechanic. I had to re-attach the carburetor after removing the excess gasket making compound, move the gas tank and upgrade its' attachments, repair the clutch cable that separated on my first ride, move the bicycle gear shift levers and re-route both gear cables, re-work the chain tensioning system, and re-route one brake cable. |
| AJ and Brittney came for a Thanksgiving breakfast, and after helping me work on the bike, AJ rode it to (and from) the afternoon Thanksgiving festivities of Brittney's family in Mammoth. The bike is powered by a two-cycle engine, which came with detailed instructions about "break-in procedures." I'm naturally skeptical, and fail to see the need for all of them, but none-the-less, I am attempting to follow them faithfully. One of them calls for keeping the speed below twenty mph, so I don't yet know the full capacity of the little beast. It did manage to bring AJ back up the hill without much trouble (even if he did freeze his toes), and that bodes well... |
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The engine came from China and the users manual that came with it uses English words with chinese syntax. With that caveat, the manuel gives some "Specification, Performance, and Parameters" that are interesting. If I read the smeared lettering on the side of the engine correctly, the displacement is 60 cc (or 3.66 in3). The manuel gives the "speed limitation" for this engine as 35 km/hr (21.7 mph), suggests that it generates 2 horsepower at 5,000 rpm (or 4 to 5 horsepower at 6,000 rpm), and lists the "oil consumption" as 2.0 L/100 km (118 mpg). |
| It will be interesting to see how close these specs are to the actual performance. The chain driven by the engine has the same pitch as the bicycle chain, but is half again as wide. The clutch disengages the engine from this chain, but the sprocket on the bicycle wheel does not disengage, such that the chain moves when the wheel does. At low speeds, this is not a problem, but above 10 mph, the inertia and friction inherent in pulling a chain that large through the angle imposed by the chain tensioner and around the small engine drive sprocket, makes the bicycle feel like it is being driven through two inches of molasses. |
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To this point, I am a bit disappointed with the machine. What I want is a bicycle that has auxiliary power available when needed. What I have, is a small, light, possibly underpowered motorcycle, with auxiliary petals that are used to start the engine and ferry the bike around at low speed. To transform the one into the other, I need a clutch mechanism that will allow the rear sprocket on the engine side of the drive train to "free wheel." Any thoughts? |
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Post Script: I found what appears to be the same engine on ebay, with a buy-it-now price of $125.99, which includes shipping. There was also a blurb about the engine size. Apparently in the "East" (China/Japan/Korea) the size of an engine is taken to be the total volume inside the cylinder at the bottom of the stroke, while we in the US describe the engine size as the volume swept out by the piston as it moves from the bottom to the top of it's stroke (cid = cubic inch displacement). The Chinese (who build this engine) list it's size as 80 cc. We (in the US) would measure the bore at 47 mm and the stroke at 38 mm and calculate the displacement as 65.9 cc, or 4.02 cubic inches. So, I have a four oh two on my bike (just a bit smaller than Ford's classic four oh nine engine that the Beach Boys sang about). This advertisement claims that after the engine is "broken-in," it generates 3 horsepower at 5000 rpm (or 5 to 6 hp at 6000 rpm), gives the fuel consumption as 120 to 170 mpg, and lists the "speed limitation" as 25 to 40 mph. Given that these values carry a disclaimer stating that actual performance depends on the care given the engine along with the stresses it experiences during its' "break-in" period, I would guess that they are too high by perhaps 25 to 50%. This mythical "break-in" period is 300 miles, so it will be awhile before I can actually compare my numbers to theirs. In fact, given that I lack a convenient way to measure both rpm and horsepower, the precise meaning of "speed limitation" is not intuitive obvious, and the small volume (2 liter), gauge-less fuel tank that requires pre-mixed gasoline/oil, I may never be able to make a truly accurate comparison. |