Sprocket question

[TwoHundredEx]

I understand how different sprocket sizes affect torque and top speed, but one thing I never understood was this.
Say you have an 11/40 ratio, if I go up to a 12/42, will I feel any difference? I'm going up an equal amount in the front and rear, since one tooth in the front is equal to 2 in the rear right? Wouldn't that mean that my top speed and torque will stay the same? Seems like a simple question, but I've never had a definitive answer.

Also, do any other models use the same sprocket hub as an '83/85 200X?
I want to go larger than the stock 40, but that's all I can find online. Haven't checked my dealer yet though.

[NINJA]

You're right, it's essentially the same ratio, but now you're going to demand more from your engine, does it have the torque to pull that? Someone correct me if I'm wrong here. But by doing a change such as this not only do you increase rotating mass (wouldn't really be noticeable) but you also decrease the amount of available torque on the bottom end of your power curve.
Also, from what I've seen, there isn't any other sprockets that swap over with the x.

[The Goat]

try dennis kirk man, cause i swore i saw bigger than 40.

[TwoHundredEx]

You're right, it's essentially the same ratio, but now you're going to demand more from your engine, does it have the torque to pull that? Someone correct me if I'm wrong here. But by doing a change such as this not only do you increase rotating mass (wouldn't really be noticeable) but you also decrease the amount of available torque on the bottom end of your power curve.
Also, from what I've seen, there isn't any other sprockets that swap over with the x.

Well the engine is lacking torque as it is, so I don't think I want to do that then. I really only want a bigger rear sprocket, the front was just to help out with the chain angle, but it's better now anyway.

try dennis kirk man, cause i swore i saw bigger than 40.

Just checked and all they have is 35-40.

[NINJA]

You could always swap over to an 82 250R rear axle, then you could run anything from a 40-44 tooth rear sprocket.

[TwoHundredEx]

I could... but I really don't want to.
I JUST finished changing axles 2 days ago.

How hard do you think it would be to modify one?
As in re-drilling to match the X hub. I've done it before with a set of wheels on our Bayou, but the hub fit perfectly into the wheel so it made centering it easy.
I'd imagine centering it would be the most important part, but I don't see why it wouldn't work.

[NINJA]

Yeah dude, you can do that. When you find out what's close enough, let us know on here. I'm sure a few people could use that information. You could also possibly have an adapter plate made to make it use different sprockets, or go totally redneck and weld the desired sprocket onto your old one!

[TwoHundredEx]

Yeah dude, you can do that. When you find out what's close enough, let us know on here. I'm sure a few people could use that information. You could also possibly have an adapter plate made to make it use different sprockets, or go totally redneck and weld the desired sprocket onto your old one!

I've definitely thought about welding one on there temporarily...
Would that throw off the chain alignment enough to matter?
I beleive I've got a 43, and 45 tooth in the shed...

[NINJA]

I don't want to answer this question! But, it will work for a while. Now look what you made me do!

[TwoHundredEx]

I don't want to answer this question! But, it will work for a while. Now look what you made me do!

I definitely wouldn't keep it for long, my low end is just really lacking right now. I almost have to double clutch it sometimes to get it rolling in first unless I drop the clutch. I'm going to scan Dennis Kirk over the next couple days and see if I can find anything close.

[McDerry]

I understand how different sprocket sizes affect torque and top speed, but one thing I never understood was this.
Say you have an 11/40 ratio, if I go up to a 12/42, will I feel any difference? I'm going up an equal amount in the front and rear, since one tooth in the front is equal to 2 in the rear right? Wouldn't that mean that my top speed and torque will stay the same? Seems like a simple question, but I've never had a definitive answer.

Also, do any other models use the same sprocket hub as an '83/85 200X?
I want to go larger than the stock 40, but that's all I can find online. Haven't checked my dealer yet though.

Rear teeth divided by front teeth man. 11/40 is 3.63 where as 12/42 is 3.5.

[TwoHundredEx]

Rear teeth divided by front teeth man. 11/40 is 3.63 where as 12/42 is 3.5.

What do those numbers mean though?


I've decided not to weld sprockets together either. The sprockets I was thinking of are already on a mini bike so I will have to buy some anyway.

[super90]

Thoes numbers would be the gear ratios. I always wondered if thoes sizes would be the same too. The ratios would be close but not exactly the same, probably barely noticeable.

[TwoHundredEx]

Well I can't find any sprockets that look similar right now. I'm going to keep looking but not expecting to find much. I'm hoping the smaller tires will be enough.

[McDerry]

3-4% difference. It will feel like you've lost 1hp horsepower buy going with the 12/42 with stock tires (22" balloons). Top speed probably wont be increased as it takes x amount of hp to move x amount of weight to a certain velocity, assuming the engine isn't maxing out its operating rpm in high gear, and your still running stock specs.

The real difference is the increase in gear ratio will allow you to run 21" tires and have it perform like a stock machine.