Originally Posted by Nashville Kat
40-45 is probably not a realistic goal for a China girl-
Mine, with light narrow 700c wheels and a 34 sprocket might push 35 if I really pressed it- I don't- the motors are notoriously unreliable, while my bikes are like a second car- I want long performance out of them- not break neck speed.
Granted, I'm only running a stock NT Speed carb- so a change there might yeild me some more screaming RPMS, but I feel like I'm pushing the limits on a bike anyway at that speed- and I raced USCF fourteen years road and track in my crazy days. Plus my bikes are set up with as much alloy and titanium as practical- but also baskets racks and bags to be able to carry stuff.
I usually cruise out about 25 on my analogue speedo- probably not too far wrong- , but can get that up to 30 to stay with traffic if I want- I ride them slower all the time- at 60 I want to just cruise around the lake on my John Candy pontoon boat and enjoy life staying alive.
My 50 cc cruiser- set up much the same otherwise is about 5 mph slower all around, with a 39 alloy sprocket- and it's all flat here- a few years back I was getting up near the tops of the steepest mile long climbs in southern Indiana before bogging down on a 36 if that helps- all on standard kit carburetion.
We're running with the shadows of the night.....
Your right about the most common speeds being in the low to mid 30's and for the average china girl engine that is gonna be where most of them will be, acception being the better balanced 40mm stroke PK-80 types like what dax and Neil are selling as " Gen IV & GenV " engines, I have two of them built and running and each will pull my 215 lbs down the road @ mid 40's and one is hitting upper 40's and has registered an unofficial 51.5 mph lately, but without good port work and some other goodies the average badly balanced china girl will not ever hit those speeds and will most likely find there sweet spot in the low to mid 30's even with a 36T sprocket, I know because I have a couple old bgf engines that run this way, one of them needs a 36T just to have a comfortable cruise speed of 32-34 mph and it will do it all day but beyond that the vibes are crazy bad and would kill that engine quick if it were run that way for long above low 30's.
Some just dont realize what it takes to get a china girl to do comfortable 40 mph speeds unless it has a good balance and it is built so that it can breathe well and set up on the bike right.....
Good advice Kat you are correct.