Average speed of 2/stroke

geebt48cc

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Feb 2, 2010
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Location
Va.
Running around 20-25 is just fine around the city thing. The "Boys in Blue" just don't understand a bicycle going much faster than that. So, 80cc and 48cc have about same top end? :rolleyes:
 
Yep, I agree, more than about 25mph not only upsets the cops, but cars aren't sure how to react. Too often, when they see a bicycle, they judge it's speed as lower.
I've had countless cars cut in front of me at roundabouts and intersections, because they thought they had enough time.
On the open roads, though, I sit on 35-40mph.

From what I've read here, the 48cc engines rev higher, but the 66cc has more overall power. ie The 66cc would rev higher up hills.
Apparently, the engines' bottom-ends are balanced for the 48cc top-end, hence the higher revs in the 48.
 
Yes Steve, I very much agree, but the only reason I went with the 48cc is because of the legalities. I really need that extra cc's of the 66, but I figure that I can feel better about telling people that I road 20 miles and peddled up some good sized hills.

Uno, pretty good averaging 22 mph isn't bad in the hills of SW Va. Uno, I've been told that I need to get a expansion pipe. Wonder how much that would help the 48cc Grubee

Glen
 
22mph is fine.
Our engines have nothing on them to indicate their capacity, and since the 48cc and 66cc look the same...
Still, we're restricted to a max of 200W, therefore both 48s and 66s are technically illegal.
They turn a blind eye, for now. I've been seen by more cops than I can remember in 500km and they've never stopped me. Too fast, I always get away. (kidding)
Even went through a 'random breath testing' station and the cop winked and signalled me on.
If I am stopped, I'll say it's a 200W 48cc engine and cross my fingers.....
 
48cc vs 66cc

Steve, I got a 66cc grubee and i took all the badges off it and altered proof of purchase to show 49cc so when i get my title from state (or if) its a moped not a motorcycle. legal loop hole in MN. hopefully they dont want to do an inspection. think they would find out if inspected
 
Yeah, I was thinking of buying a Rock Solid Engines certified 200W, 48cc engine, then fitting the 66cc top-end from my current engine.
We need that cerificate here - the onus is on the rider to prove his engine doesn't exceed 200W. It's not up to the state to prove otherwise.

Since, for you, it's a capacity issue, you'll probably be OK, unless they pull the head off and measure the bore and stroke during inspection, but that's not likely.
 
well, yes...a 66 c.c. (80 c.c.) has more bottom end torque than the 48 c.c., but top end speeds are pretty much the same. I have a 48 c.c., my friend has a 66 c.c. we both have pretty much the same set-up as far as bikes, wheels and rear sprockets go. (he has a few pounds on me as far as our weight goes).
bone stock, his bike would walk away from mine on take off, but i could catch him and SLOWLY pass him on the top end.
since then, i've added an expansion chamber a high flow air filter and tuned the carb. his is still all stock and he can still get me on the take off. but now i can catch him sooner, and on the mid range / top end, i can pass him and keep going with no problem at all. he can't catch up to me once i pass him. i have a speedo on my bike (not sure how accurate it is) but it's been reading 28-30 mph on the top end.
listening to the 2 engines, it's obvious that my 48 c.c. revs higher and quicker than his 66 c.c.
the advantage to the 80 c.c. is the bottom end torque.
 
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22mph is fine.
Our engines have nothing on them to indicate their capacity, and since the 48cc and 66cc look the same...

wow really? I think it's law that they have to be marked, yeah? the 3 i've seen from 3 different vendors were all marked with cc, serial number, etc.
 
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