Blanket Federal Coverage for 50cc Ceiling - How?

i know this is a techie question, but it's inspired by a legal issue.

briefly (please correct or expand): "displacement" is about the working volume, no? well, on 4-stroke engines the entire stroke is technically the factor when determining displacement. on my "70cc" engine, the "compression" stroke doesn't start until the piston fully covers the highest port (exhaust)...the top edge of the exhaust port is 28mm from the top of the stroke.

47mm bore X 28mm stroke...you're not gonna believe what that comes out to...48.6cc

is there some set of standards (technical or legal) set to paper somewhere that would clear this up for me?

somebody set me straight, because my next engine will be legally under the limit whether i like it or not.
 
Hi Aug,

In the book 2 stroke tuners guide I believe they used the term "effective displacement" to describe the area that the piston sweeps when the piston covers up the both the intake and exhaust ports and begins the actual compression phase on a 2 stroke engine (the power producing stroke)....this is somewhat different than the "total" displacement than the piston actually travels or "sweeps" during an entire crankshaft revolution....As an interesting aside, it is only the "effective displacement" phase of the piston's travel that causes power to be made...and most laws read something to the effect that a motorized bicycle can be "powered" by an engine displacing less than 50 CC...and since power is only being made when the ports are closed I would say that effective displacement rather than total displacement be used in determining engine "size" thus I would have to say, on a two stroke at least, that the effective displacement is what should be used in determining engine size...How a police officer or court would rule would be interesting but I believe we can now legally run 70's with abandon! ;-)

Come to think of it How was 50 CC or less made a standard?....If we are going to fight for a federal standard perhaps we could (while we are at it) ask for a higher maximum engine size?....a good argument could be made that increased safety would result by allowing a more powerful engine....better able to keep up with traffic....fewer cars swerving around the otherwise slow motor biker etc.....As an example, we have a twisty 2 lane road near Charlottesville, complete with blind hills and corners that many bikers like to ride (you know the ones that dress like they should be in the Tour de France"),
Cars will often risk life and limb to pass the slow pedaling cyclist just to keep moving at
the 35 (nominally....since most people speed there anyways) MPH speed limit....So in theory a faster moving motored bike could be safer for all (safer for on coming traffic since they won't have to worry about a head on collision as another drivers attempt to pass a slow cyclist, safer for the driver following the cyclist since he/she may not decide to pass the cyclist if they are doing at least a "reasonable" speed....And safer for the cyclist to boot....Win win win....So anybody out there for more legal displacement ? ;-)
Andrew
 
thank you, andrew...i didn't have the facts but i suspected i was technically correct. i'll continue using my "70" and start referring to it by its working displacement of 49cc.

to answer the size issue with opinion...since we've already been handed a 50cc federal "sanction" why fight it? use it as our main weapon, i say.

besides, the more 30mph motoredbikes we get on the road, the less the speed disparity matters.
 
Hey Augie, thanks for starting this thread. Made me think. My little town has a panel looking into the concept of "Peak Production" for the City Council (ramifications of decreasing supplies of oil). I should talk to them about making sure that local ordinances look favorably on motored bikes. They're a bunch of "Greenies" anyway, and so should be a good audience.
Many cities down south have, or probably will soon have, such panels because of increasing impacts on city infrastructure of rising fuel prices. Might be a good place for people who are ready for an intro to activism from inside the system.
 
activism from inside the system...
Click to expand...
is way overdue...time to take back our country and it has to be done right if we're gonna rebuild our global reputation.

"Let the Solution BE The Revolution."
 
bump

gone_fishin said:
thank you, andrew...i didn't have the facts but i suspected i was technically correct. i'll continue using my "70" and start referring to it by its working displacement of 49cc.

to answer the size issue with opinion...since we've already been handed a 50cc federal "sanction" why fight it? use it as our main weapon, i say.

besides, the more 30mph motoredbikes we get on the road, the less the speed disparity matters.
Click to expand...

people are debating these things quite harshly...lets find a way to unite the 50 states on this issue...
 
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