Help me with wheel / tire physics

[Ross and Alice]

OK now,, it seems to me that if you go to a larger dia rear tire and wheel, this will slightly increase your power, but decrease your top speed slightly.

Perhaps not even noticeable,,,, but bigger is slower with power, smaller is faster with less power.

The tire store guy disagrees,,,

Who's correct???

[lvnalolife]

The bigger tire, the harder it is to spin, therefore less power, but if you have the power it will give you more top end.

Think about it in terms of real trucks. See how slow and hard it is for the lifted trucks to take off while a stock truck of the same model will smoke it off the line. Once the lifted trucks get moving they will have a higher top speed at the same rpm as the stock truck.

So as you can see, you don't ever get more power, you just gain in how you want ot use it. Smaller tire, quicker out of the hole, bigger tire, more top end. But be careful sometimes the bigger tire will hurt you if you are trying to haul a$$ up a big hill, if your quad doesn't have enough power to turn them.

Hope this helps.

[dunefreak]

Taller tire- requires more power to turn/ higher top speed due to "taller"gearing

Smaller tire- easier to spin/ less top speed due to "shorter" gearing

[Ross and Alice]

Think of it this way:

If you have a larger rear sprocket on your quad,, then you have a slower top but more powerful low end.

The same principal should apply to the larger dia tire and wheel.

Bigger dia rear tire and wheel = increased low end power lower top end speed

Smaller dia tire and wheel = less low end power but more top end

[dunefreak]

Think of it this way:

If you have a larger rear sproket on your quad,, then you have a slower but more powerful low end.

The same principal should apply to the larger dia tire and wheel.

Bigger dia rear tire and wheel + increased low end power lower topend speed

Smaller dia tire and wheel + less low end power but more top end

You can't look at it that way. Yes a larger rear sprocket gives you a more powerful low end. The reason that makes it like that is cause the wheel speed is being decreased causing the eng to turn more rpm's. If you add height to the wheel/tire- you are making the revolutions of the wheel take longer to complete thus making the engine rpm's lower and making it lug down. Hope that didn't sound too confusing. :huh:

[wingnut]

Taller tires will cost you bottom end, but increase top speed.

[Don29palms]

Taller tires have the same effect as putting on a smaller rear sprocket or a larger front sprocket. No matter what you do to your tires it will not effect the horsepower output of your motor . It will effect how the horsepower is used and at what RPM it is used. It takes more horsepower to spin a taller tire than a shorter tire for many reasons. The main reason is, as stated before, a change in gearing ratios.

[Ross and Alice]

OK,, that explains it.

I'm ordering paddles for sons z50 and I'll stay at stock size or slightly smaller.

Thanks for all the imput.

[Don29palms]

I know Sand Tires Unlimited makes those tires. They shave down stock tires and bond on the paddles.

[Ross and Alice]

I know Sand Tires Unlimited makes those tires. They shave down stock tires and bond on the paddles.

Thanks.

They Don't answer their e amils or the phone,, but I'll check again.

I found a set from Gecko too.