minimum sprocket with 49cc

cumminsbayou

cumminsbayou

New Member
i have a 49c 2 stroke motor, it has no sprocket so i ordered a 39 tooth for it. Is this to steep of a sprocket for the stock motor on a 26in bike?
 
No. You're right in the ball park for a good all-round sprocket size for most types of riding. If you have steep hills to climb or you weigh a lot you might find you'll be doing a little pedal assisting but for flat ground you'll be good.

A 40 to 44T sprocket is a good range unless you're looking for maximum top speed or climbing steep hills a good part of the time. Think of your bike as a car with one gear. Your 39T puts you in something like second gear of a car where a larger rear sprocket, 44 to 48T is more like first gear and a smaller sprocket, 36, 32, even 28T is like being in high gear, 3rd or 4th.

You should be good with 39T
Just curious, what kit did you get that came without a sprocket?

Tom
 
I'd be more apt to go with a 44t on the small 2-stroke. I used to run 44t on my 66cc 2-strokes and found it to be a good overall gearing set-up. I could climb steep hills with ease and still go plenty fast on the flats. Didn't need to pedal on take-offs either. Just my opinion.

dnut
 
scotto- said:
I'd be more apt to go with a 44t on the small 2-stroke. I used to run 44t on my 66cc 2-strokes and found it to be a good overall gearing set-up. I could climb steep hills with ease and still go plenty fast on the flats. Didn't need to pedal on take-offs either. Just my opinion.

dnut
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precisely...44tooth here and like it better than my 41...just MY opinion tho
 
2door said:
No. You're right in the ball park for a good all-round sprocket size for most types of riding. If you have steep hills to climb or you weigh a lot you might find you'll be doing a little pedal assisting but for flat ground you'll be good.

A 40 to 44T sprocket is a good range unless you're looking for maximum top speed or climbing steep hills a good part of the time. Think of your bike as a car with one gear. Your 39T puts you in something like second gear of a car where a larger rear sprocket, 44 to 48T is more like first gear and a smaller sprocket, 36, 32, even 28T is like being in high gear, 3rd or 4th.

You should be good with 39T
Just curious, what kit did you get that came without a sprocket?

Tom
Click to expand...
ok that is what i thought about it. How fast do you think it will go? i got the kit used from a guy in south florida for 45 dollars all i needed was the sprocket
 
cumminsbayou said:
ok that is what i thought about it. How fast do you think it will go? i got the kit used from a guy in south florida for 45 dollars all i needed was the sprocket
Click to expand...
As long as the carburetor is tuned right and the engine isn't worn out, you should easily see the high 20s, possibly 30.
Do you know what carburetor you have? There is a lot of good information here on tuning the carb. Spark plug, plug gap, tire type, most common terrain, all of these play into the speed attainable. What fuel/oil ratio do you plan to run?

Tom
 
i think the carb is stock from what i can tell but i want to rejet it and put a different filter on it, im planning on buying a huffy signal speed bike with like 3in wide tires on it, i will most likely drive it on flat/mild hilly roads, i all so will run 32 to 1 mix
 
I'm running a 39 alloy sprocket on a 50cc with an NT 66 Speed carb on a billet intake-

It really does pretty well here in flat Florida- I'm closer to 200 than I want to admit, and the bike is set up with alloy 700c rims and fairly 32mm tires- so it really rolls well-

I've thought about going down to a 36 on it to get about the same same cruise with less RPM most of the time- on the otherhand, a good stiff headwind will slow me down a bit now- I wouldn't want to do any climbing with it- so I've been slow to change

I'm getting probably 25 cruise and upwards towards 30 with no headwind or with a tailwind- but that's just an estimate based mostly on what my speedo tells me on my 66 build- which I hardly ever ride- the 50 is just so lightweight and convenient- and I roll and roll and roll around town here and save all kinds of gas without worrying over break neck speeds.

Got a basket on the front and getting ready to put an alloy rack and nylon trunk bag on the back- to which I can attach some nylon panniers I have- if and when I want.

http://www.youtube.com/watch?v=k3ejWhPVZaY&list=UUOcL4qNa1PxaUzgfjeERryg&index=4This film is BEFORE i put the NT Speed carb on- a bit more speed now. And the 66 is down to a 34 alloy sprock- fast and smoooooooth.....
 
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