Originally Posted by ProDigit
Here in Miami cops are pretty much unlearned.
They don't even know what a moped is, so they leave 2 wheeled vehicles mostly alone.
As far as the walmart bikes, they are meant to go 30MPH.
Any decent man can pedal 30MPH on a geared bike. A beach cruiser generally does not go very fast, but their frames seem pretty solid enough to go faster IMHO.
40MPH may be a lot, but then again, I'm only aiming for these speeds at WOT. More than likely I'll be running at ~ 2/3rd that speed.
The comment about the 50cc is pretty remarkable. I know that a 66cc is larger, has more torque, and top engine RPM's are about the same. But if you have better acceleration, then you could reduce the rear sprocket, compensating top speed with torque.
You might ask: Why do that, if you can get the same with a 50cc?
Well, if there's any wind, or uphill, a 60cc, even with slightly heavier gearing, will more than likely keep up, while a 50cc might not...
Sometimes an "unlearned" cop adds up to a PITA to a motorized bicycle rider. Sure they ignore scooters, they are licensed and clearly legal, but a dirt bike is not street legal and so an motorized bicycle might end up on an "unlearned" cops radar where a scooter wouldn't. Specially if you're screaming around at 40MPH!
I don't think many people that buy a bike at Walmart hit 30MPH on them, and if they do it's down the biggest hill they will never climb back up again! LOL No amature cyclist is running around at a sustained 30MPH pedaling a bike the way you will with a motor on it. Not to mention the extra weight, and vibration, and required stopping power, and how much more impact those small bumps have on cheap rims when your moving that fast, or how the cheap bearings just don't hold up to that continued abuse very well. Or that you said you want to do ~40MPH for cruising in the burbs...
I am just trying to be honest with you, a cheap bike isn't up to the task as described by you in your original posting. You might get away with running a cheap bike as a casual cruiser, but to push into the 40MPH range for long roads out in the suburbs I would suggest you start out with something better, or adjust your expectations downward.
Speaking of expectations, don't get them too high or put too much faith in numbers you may see about these china girls. I have seen specs all over the board for engines that pretty much perform about the same. So you can run numbers all day, but good luck getting that from the paper to the pavement. I have heard said the motors were all designed to be 48cc and they up-sized the top end to make the 66cc, but the 48cc is a more balanced motor because of it. So don't expect the 66cc to be like the 48cc on steroids, maybe just on esspresso! lol
Not trying to rain on your parade, just trying to be real with you.