rear sprocket size?

fauxmaster · #1 07-09-2009, 08:49 PM

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?

Cabinfever1977 · #2 07-09-2009, 09:01 PM

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.

matt167 · #3 07-09-2009, 09:55 PM

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..

Cabinfever1977 · #4 07-09-2009, 10:02 PM

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.

matt167 · #5 07-09-2009, 10:40 PM

Quote:

Originally Posted by Cabinfever1977

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.

got to remember, he has double the rolling force.. 2 rear wheels, full axle and a bit heavier than a bike

igore · #6 07-09-2009, 11:09 PM

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

Creative Engineering · #7 07-10-2009, 12:38 AM

Good grief!!!

Jim

matt167 · #8 07-10-2009, 08:06 AM

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

**Bikeguy Joe** · #9 07-10-2009, 08:59 AM

Quote:

Originally Posted by Creative Engineering

Good grief!!!

Jim

FO'SHO'!!!

**Bikeguy Joe** · #10 07-10-2009, 09:00 AM

Quote:

Originally Posted by matt167

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

Don't forget the china engine has an internal reduction.