rear sprocket size?

sprocket size makes difference in speed or torque?

  • smaller sprocket = higher speed

    Votes: 3 75.0%

  • bigger sprocket = lower speed

    Votes: 0 0.0%

  • smaller sprocket = more torque

    Votes: 0 0.0%

  • bigger sprocket = less torque

    Votes: 1 25.0%
  • Total voters
    4
  • Poll closed .
fauxmaster

fauxmaster

New Member
im building a trike, it is a 3 speed to the rear stock. the cross shaft that has the 3 speed sprocket will only let me clear a 6 inch max sprocket which will be mounted to directly to the shaft and not the bike spokes... does anyone have any ideas as to what will happen with such a small sprocket mounted to the back, will i be traveling faster but slow to get there or slower but a **** of a lot of torque?brnot
 
you have your poll wrong. you have the torque backwards.
the correct answer is this:
smaller sprocket= less torque/slower acceleration/faster top speed
larger sprocket= more torque/faster acceleration/slower top speed

6" is around the size of a 36t sprocket i think

you will be traveling faster but slow when starting out , with less torque.
 
Last edited:
a pic to show your issue would be very helpful.. the bigger the sprocket, the more torque you will have, but a reduced top speed.. smaller will be opposite..
 
also it would help if we knew what engine you are using.
if the engine is atleast 1.6hp+ and you can fit a 36t sprocket on there,you should be fine. you might not go up steep hills or take off fast but once you get going, you should be able to fly down the road at some good speeds.
 
Cabinfever1977 said:
also it would help if we knew what engine you are using.
if the engine is atleast 1.6hp+ and you can fit a 36t sprocket on there,you should be fine. you might not go up steep hills or take off fast but once you get going, you should be able to fly down the road at some good speeds.
Click to expand...

got to remember, he has double the rolling force.. 2 rear wheels, full axle and a bit heavier than a bike
 
question
I have a 3 hp 4stroke engine with a 10 tooth drive sprocket driving a 52 tooth wheel sprocket is that about right???
thanks
 
just reread my post... geared tall unless it's got 30" tires.... on a China, it would be a hill climber with a top speed of about 20, but a 3hp 4 stroke has enough torque for the hills, and really 40 tooth would be more than sufficent
 
matt167 said:
just reread my post... geared tall unless it's got 30" tires.... on a China, it would be a hill climber with a top speed of about 20, but a 3hp 4 stroke has enough torque for the hills, and really 40 tooth would be more than sufficent
Click to expand...

Don't forget the china engine has an internal reduction.
 
this is a harbor freight engine 3600 rpm, this 52 tooth sprocket I found at a garage sale. maybe a tooth change on the clutch sprocket
 
Bikeguy Joe said:
Don't forget the china engine has an internal reduction.
Click to expand...

yea, I know, I'm just figuring on what a stock 44 tooth can do, and going from there... as far as the 3hp engine, it'll have about 4 ft/lbs of torque without gear reduction. enough to get up most hills without too much gear
 
igore said:
this is a harbor freight engine 3600 rpm, this 52 tooth sprocket I found at a garage sale. maybe a tooth change on the clutch sprocket
Click to expand...

I can tell you the HF 80cc needs at least 80-90 tooth rear and disable governor to get reasonable top speed.
 
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