I started my test just now I need to put the results down before I forget
33cc chainsaw engine bike friction drive. 20" rear wheel 3/4" drive roller covered with fine sand and Jb weld. Effective size of the roller approx 1"
3.5miles @ 6oz of gasoline. Effective mpg approx 74.6... I had hoped for more. I do have some hills on my test track so this is the average around my neighborhood city driving. Shoes was right a little over 10miles per tank. Those little weed eater tanks are pretty close to a pint. If you are going more than ten miles you better have spare gas.
The ryobi 31 cc did the same test track with with less gasoline
3.5miles @ 5 oz = 89.6mpg and change its a significant difference but so is the performance I noticed. This bike also has the 3/4 inch drive with sand and jb weld. It is running knobbie tires though which may account for the slightly worse performance.
Results for the 42cc chainsaw engine.
3.5miles @ approx 7oz = 64mpg The results are what you would expect. The tire is a smooth road tire. The drive wheel is much larger than on the other two bikes. about 1 1/2 inches as a matter of fact. It is also covered with jbweld and sand.
The smaller engine got the best gas mileage with good performance . The slight larger engine got 15mpg less but also got a noticeable increase in power. The still larger engine got 30mpg less than the smallest but is significantly more powerful.
I would sacrifice the milage for the better climbing of the hills I think. The 33 also seems to do a little better on the flat... but for economy in purchase and use you cant beat the 31cc weed whacker as a helper engine.
The 42cc is by far the better cruiser engine. On the small or moderate hills it is a dandy. On the long steep ones I remember it as being a bit of a dog. I think that is because of the size of the drive wheel.
But for my short run errands it is over kill. The big drive wheel makes it less acceptable for the big hills around here.
I think the best all around bike for this area would be the 33cc with the small drive wheel on the full suspension frame. Now that I know how to mount an engine on it, when the ryobi goes I expect I will switch to that frame.
So there you have my results. Very unscientific I admit, but more scientific than my swag system estimate. I had top alter the figures. i double checked my map and found that I hadn't take everything into consideration. Like I left part of the test track off. So anyway these are the numbers now.
33cc chainsaw engine bike friction drive. 20" rear wheel 3/4" drive roller covered with fine sand and Jb weld. Effective size of the roller approx 1"
3.5miles @ 6oz of gasoline. Effective mpg approx 74.6... I had hoped for more. I do have some hills on my test track so this is the average around my neighborhood city driving. Shoes was right a little over 10miles per tank. Those little weed eater tanks are pretty close to a pint. If you are going more than ten miles you better have spare gas.
The ryobi 31 cc did the same test track with with less gasoline
3.5miles @ 5 oz = 89.6mpg and change its a significant difference but so is the performance I noticed. This bike also has the 3/4 inch drive with sand and jb weld. It is running knobbie tires though which may account for the slightly worse performance.
Results for the 42cc chainsaw engine.
3.5miles @ approx 7oz = 64mpg The results are what you would expect. The tire is a smooth road tire. The drive wheel is much larger than on the other two bikes. about 1 1/2 inches as a matter of fact. It is also covered with jbweld and sand.
The smaller engine got the best gas mileage with good performance . The slight larger engine got 15mpg less but also got a noticeable increase in power. The still larger engine got 30mpg less than the smallest but is significantly more powerful.
I would sacrifice the milage for the better climbing of the hills I think. The 33 also seems to do a little better on the flat... but for economy in purchase and use you cant beat the 31cc weed whacker as a helper engine.
The 42cc is by far the better cruiser engine. On the small or moderate hills it is a dandy. On the long steep ones I remember it as being a bit of a dog. I think that is because of the size of the drive wheel.
But for my short run errands it is over kill. The big drive wheel makes it less acceptable for the big hills around here.
I think the best all around bike for this area would be the 33cc with the small drive wheel on the full suspension frame. Now that I know how to mount an engine on it, when the ryobi goes I expect I will switch to that frame.
So there you have my results. Very unscientific I admit, but more scientific than my swag system estimate. I had top alter the figures. i double checked my map and found that I hadn't take everything into consideration. Like I left part of the test track off. So anyway these are the numbers now.
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