loquin
Well-Known Member
Bamabikeguy loved his R/S for long trips...
Japanese 2-stroke -OR- 4-stroke for 700 Mile, One-Way Ride?
- Thread starter sparky
- Start date
happycheapskate
Active Member
Video or it didn't happen....
43.5 mph with a 33cc motor
43.5 mph with a 33cc motor
happycheapskate
Active Member
I voted for the 4 stroke. I think you should break in the motor before your trip, to be safe. If I were going on such a trip, with the choice of engines you mentioned, I think the 4stroke would probably be stronger. I could be mistaken though. I think if you don't over-speed it or overheat it, it should be fine, esp. being new.
If you don't wish to use a trailer, you might do ok with a steel rear rack and milk crates for luggage. I use 1 milk crate and have put 60 lb of groceries in it and tied to it, on my happytime bike. The bike felt stable enough at 25-30, but did feel like a passenger was riding it. If you put the milk crates on the sides, it should lower the center of gravity some.
Dave C,
Thanks for the tip. I don't plan on doing any 700 mile rides, but I like rear tanks and rear engine kits best. I might like to have a 1 gallon tank.
If you don't wish to use a trailer, you might do ok with a steel rear rack and milk crates for luggage. I use 1 milk crate and have put 60 lb of groceries in it and tied to it, on my happytime bike. The bike felt stable enough at 25-30, but did feel like a passenger was riding it. If you put the milk crates on the sides, it should lower the center of gravity some.
Dave C,
Thanks for the tip. I don't plan on doing any 700 mile rides, but I like rear tanks and rear engine kits best. I might like to have a 1 gallon tank.
sparky
Active Member
I'm 100% positive that I could do it with a chain-driven TLE33 on a 29'er!! I only weigh ~155 lbs or so, as well.
But I'm sure it could be done if I had the will. Just not my cup o' tea, yet... as my 29'er is my SHTF ride, and I'm not about to change anything about it.
AWESOME!!!
Thanks a ton, loquin!
Sweet idea on the milk crates!! That is definitely my style. Will have to be on the lookout now...
5
5-7HEAVEN
Guest
Lol, I have never seen such optimism!
Would you presume that since your 1.25hp engine propelled you to speeds of 33mph, then 2.5hp would make you go twice as fast?
My first MB had 1.6hp and 20" wheels. It topped out at 27mph.
My next MB had 2.2hp with 26" wheels. It topped out at 32mph.
My twin engined MB had 5.5hp w/26" wheels. It topped out at 39mph.
My 5hp 460 engine pushes my bike w/26" wheels past 45mph.
Think about that.
Ever hear of the law of diminishing returns?
sparky
Active Member
Ever hear of keeping things as light as possible, tweaking the gearing to be higher than normal, and leaning out the fuel/air mixture??
That's what I do. My bike, which I can still pedal with ease, doesn't weigh more than 40 lbs.
My buddy has a Go-Ped Riot w/ GP460 engine... it's got like 8" or 10" tires... he changes out the drive shaft sprocket from a 7 tooth to a 9 tooth and can reach a top speed close to 55 mph.
If you want faster speed.... the answer is simple --
- increase teeth on drive shaft sprocket
- decrease teeth on wheel sprocket
- increase tire diameter.
I assure you that 43 mph on a chain-driven 29'er would be possible with ANY 2-stroke. And just for the record, my 33cc was advertised to be 1.6 hp, since it's a Tanaka knock-off.... not 1.25 hp.
You seem to have many setups, all with completely different engines. When increasing tire size, and keeping the engine & gearing the same... what were your results?
That's what I do. My bike, which I can still pedal with ease, doesn't weigh more than 40 lbs.
My buddy has a Go-Ped Riot w/ GP460 engine... it's got like 8" or 10" tires... he changes out the drive shaft sprocket from a 7 tooth to a 9 tooth and can reach a top speed close to 55 mph.
If you want faster speed.... the answer is simple --
- increase teeth on drive shaft sprocket
- decrease teeth on wheel sprocket
- increase tire diameter.
I assure you that 43 mph on a chain-driven 29'er would be possible with ANY 2-stroke. And just for the record, my 33cc was advertised to be 1.6 hp, since it's a Tanaka knock-off.... not 1.25 hp.
You seem to have many setups, all with completely different engines. When increasing tire size, and keeping the engine & gearing the same... what were your results?
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loquin
Well-Known Member
There ARE limiting factors, based on air resistance, temperature (cold air is denser air,) drive efficiency, and rider stance (an upright rider has more resistance than one leaning forward, and a recumbent rider has lower resistance yet.)
While the rider's weight has much more impact on acceleration and hill climbing top end, it has some impact on top end as well, as a heavier rider has more cross sectional area, and therefore, more air resistance.
You can get an estimate of top speed on the flat, and on slopes, if you use the bike power calculator (it estimates power required to run at a given weight, speed, slope, and rider stance)
For instance, if we enter a top speed of 43 MPH, 170 pound rider, 40 pound bike, zero wind speed and grade, a forward stance, an 85% drive efficiency, and a default 70 degree temperature, the utility estimates that 1.81 HP at the motor (1.54 HP at the axle) is needed. If we change the default temperature to 32 degrees, it calculates that you'd need an additional .14 HP to stay at 43 mph.
One other factor to keep in mind is that, assuming that all other factors are the same, the aerodynamic drag is proportional to the square of the velocity - it is NOT a linear relationship. So, with the same values as above, for 40 MPH, you would need about 1.46 HP at the motor, but to run at 50 MPH, you would need 2.85 HP! (And, at 30 MPH, only 0.62 HP)
I went ahead and ran the tool for speeds every 5 mph between 20 MPH and 50 MPH: a chart of the results is attached.
While the rider's weight has much more impact on acceleration and hill climbing top end, it has some impact on top end as well, as a heavier rider has more cross sectional area, and therefore, more air resistance.
You can get an estimate of top speed on the flat, and on slopes, if you use the bike power calculator (it estimates power required to run at a given weight, speed, slope, and rider stance)
For instance, if we enter a top speed of 43 MPH, 170 pound rider, 40 pound bike, zero wind speed and grade, a forward stance, an 85% drive efficiency, and a default 70 degree temperature, the utility estimates that 1.81 HP at the motor (1.54 HP at the axle) is needed. If we change the default temperature to 32 degrees, it calculates that you'd need an additional .14 HP to stay at 43 mph.
One other factor to keep in mind is that, assuming that all other factors are the same, the aerodynamic drag is proportional to the square of the velocity - it is NOT a linear relationship. So, with the same values as above, for 40 MPH, you would need about 1.46 HP at the motor, but to run at 50 MPH, you would need 2.85 HP! (And, at 30 MPH, only 0.62 HP)
I went ahead and ran the tool for speeds every 5 mph between 20 MPH and 50 MPH: a chart of the results is attached.
Attachments
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happycheapskate
Active Member
There are 4 and 5hp 50cc goped engines and go-kart engines available, but I don't know if I would trust them for a 700mi self supported tour.
I hope the OP has a safe trip with 100% success. Please post your favorite photos from your trip! Good luck!
I hope the OP has a safe trip with 100% success. Please post your favorite photos from your trip! Good luck!
Slackbiker
Member
I actually voted this time, for the 4-stroke, mainly cuz that's what i use. But that is almost all about being possibly more reliable, quieter, no gas/oil mixing. If the Need for Speed gets to you then the 2-stroke makes sense. Here's an amusing interview of Dave Staton who hit 47 mph on a ~40cc Mitsubishi:
http://www.wizardbrothers.com/staton.html
http://www.wizardbrothers.com/staton.html
