gear ratio

[bkrider113]

hey guys n gals, does it matter if the engine sprocket is big? I always see a small engine sprocket and large axle sprocket. I am using pulleys and a belt with a manual clutch and can only find small pulleys that I know will work. Does a smaller engine pulley create more wheel hp or is it just for clearance issues?

 

[honda02]

The ratio of the axle gear, (driven gear) to the engine gear (drive gear) is adjusted to achieve more torque on the rear wheels. The bigger the ratio, (really big in the back, tiny on the engine) the faster the kart will accelerate, but it will loose top speed this way. Usually, a bigger motor with more torque will alow you to adjust for decent accel. and a decent top speed. Its all a balance with this. Post up some pics of what your putting this on/ your motor. Hope this helps.
btw. The ratio of the diameters of pulleys also works. 5inch on the axle 1 inch on the engine. 5:1

 

[Rotore]

hey guys n gals, does it matter if the engine sprocket is big? I always see a small engine sprocket and large axle sprocket. I am using pulleys and a belt with a manual clutch and can only find small pulleys that I know will work. Does a smaller engine pulley create more wheel hp or is it just for clearance issues?

a 2-3" pulley works nicely on the engine but the biger the axle sprocket and smaller the engine sproket or pulley is the more torque cant increase horse power through gearing just torque.

 

[bkrider113]

Yes I know but my question is why is the engine sprocket always smaller. Is there a reason? I know about gear ratios. anything that has torque has horsepower Torque x Rpm / 5252 = hp

 

[jor2daje]

Its because you want to get the rpms down on your wheels, 3600 rpm at the wheels would make a kart go ridiculously fast but there wouldnt be enough torque to even get it started. By having a larger gear on your engine you increase the rpms which reduces the torque further.

 

[bkrider113]

ok but can anyone answer my question??? Why is the engine sprocket always the smaller one of the two. Is it for clearance issues? Does it actually help with wheel torque or is it just because.

 

[modelengineer]

Of course it gives more torque at the back wheels!

If you can't see this then you don't really know anything about gear ratio's at all.

Try putting a larger sprocket on the engine than the axle and see what happens. The speed calculator will give you a top speed of more than 200mph! Won't that be fun! (but the kart won't actually be able to move itself)

 

[Russ2251]

Think of a ten speed bicycle...
Why the lower ratios?
Try riding a bicycle in 10th gear from a standing stop!
Same with a gokart.
Imagine the strain on engine and drive train with a 1:1 ratio.
Something is gonna' burn up real fast.
This is basic stuff.

 

[Kaptain Krunch]

ok but can anyone answer my question??? Why is the engine sprocket always the smaller one of the two. Is it for clearance issues? Does it actually help with wheel torque or is it just because.

If you know about gear ratios then why are you asking this question? If your engine sprocket is bigger than your axle sprocket, then your axle will be spinning at a higher RPM than your engine, which is very bad for acceleration, torque, and/or even moving.

 

[rdenis]

Dude, where are you from and what do you mean by "smaller"? Everyone here is assuming you are talking about the number of teeth or diameter of the sprocket but since you insist you know all about gear ratios, then you must be referring to something else - but apparently no one here knows what the hell you are talking about.

So let's start a list what it is specifically about a sprocket that is "smaller" and see if you can get an answer you like. So, "smaller", in reference to:

1. Sprocket weight?
2. Sprocket thickness?
3. Sprocket bore hole size for shaft?

 

[bkrider113]

im an idiot and I appreciate everyone dealing with my stupidity......................sorry but im a stoner