turbobuick1
New Member
I put together 66cc powered Schwinn Meridian tricycle for a friend, but am fighting a major vibration issue. At first I thought it was just a poorly balanced (internally) engine, as it was a brand new, never run China girl. I switched engines with one of my other, well-ridden motorized bikes, and the results were unchanged. The vibration is felt VERY strongly in the seatpost, really at any speed above 10mph.
I changed my motor mounts from solid to rubber engine mounts (I know how controversial those can be) and it made a slight improvement, but still not a solution to a bad vibration. I've also filled the aluminum seatpost insert with sand and used a rubber expansion plug to hold it in, with minimal improvement.
I'm beginning to think it's just the nature of the frame of the bicycle. As opposed to some other trikes, the Schwinn is not a one piece steel frame welded with the rear axle assembly. The front portion of the bike is essentially a normal, all aluminum frame, but with 1/4" thick rear aluminum dropouts, and some reinforcement where the seatpost meets the crank.
The rear axle housing is all steel, and is fastened to the bike only at the rear dropouts with 4 bolts. I feel like this is the root of the vibration problem.
I've invested some time into this project, and it's disappointing that it is almost unrideable at anything above 10mph, as ther vibration makes your rear end go numb within 5 seconds.
And so, I'm considering another powerplant. An electric motor would definitely be a perfect solution, but the cost of batteries keeps this out of the picture.
I've also just begun looking into Harbor Freight's predator engines, four-strokes (do these have less vibes than a China girl?), Honda engines (also pretty expensive, but I know the quality is there), and so on.
Let me know what you guys think, in terms of:
1) possible solutions for the vibration
2) alternative engine suggestions
3) links to other gas-powered Schwinn Meridians, or very similiar projects.
Thanks guys!
As you can see in the pics, I've fabricated the jackshaft chain drive, engine mounting plate, fuel tank, and what I call "the cage".
I changed my motor mounts from solid to rubber engine mounts (I know how controversial those can be) and it made a slight improvement, but still not a solution to a bad vibration. I've also filled the aluminum seatpost insert with sand and used a rubber expansion plug to hold it in, with minimal improvement.
I'm beginning to think it's just the nature of the frame of the bicycle. As opposed to some other trikes, the Schwinn is not a one piece steel frame welded with the rear axle assembly. The front portion of the bike is essentially a normal, all aluminum frame, but with 1/4" thick rear aluminum dropouts, and some reinforcement where the seatpost meets the crank.
The rear axle housing is all steel, and is fastened to the bike only at the rear dropouts with 4 bolts. I feel like this is the root of the vibration problem.
I've invested some time into this project, and it's disappointing that it is almost unrideable at anything above 10mph, as ther vibration makes your rear end go numb within 5 seconds.
And so, I'm considering another powerplant. An electric motor would definitely be a perfect solution, but the cost of batteries keeps this out of the picture.
I've also just begun looking into Harbor Freight's predator engines, four-strokes (do these have less vibes than a China girl?), Honda engines (also pretty expensive, but I know the quality is there), and so on.
Let me know what you guys think, in terms of:
1) possible solutions for the vibration
2) alternative engine suggestions
3) links to other gas-powered Schwinn Meridians, or very similiar projects.
Thanks guys!
As you can see in the pics, I've fabricated the jackshaft chain drive, engine mounting plate, fuel tank, and what I call "the cage".
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