change wheel size therefore...

[parliament]

hi.

this year my team change wheel, keizer 10inch 6J
anyway I didn't know equation about chang wheel 13''to 10'' therefore what is different gear ratio.

I know gear ratio leaen experience.
but didn't know gear ratio design by data.

I'm very curious this happen.

thank you.

[parliament]

hi.

this year my team change wheel, keizer 10inch 6J
anyway I didn't know equation about chang wheel 13''to 10'' therefore what is different gear ratio.

I know gear ratio leaen experience.
but didn't know gear ratio design by data.

I'm very curious this happen.

thank you.

[nms553]

it's called research dude, not handouts

[Wesley]

2*pi*r

Next question.

[SamB]

So you switched before doing any calculations? Nice move...

[MegaDeath]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SamB:
So you switched before doing any calculations? Nice move... </div></BLOCKQUOTE>

GFR uses 10" wheels....What other reasons do you need?

[Spetsnazos]

Don't listen to the noob trolls above me...

What you guys did was a big change. One that requires considerably calculation. You basically need to re-examine your final drive ratios, suspension effects, suspension geometry and tire radius. It is not something we can help you with unless you have a specific question.

First look at
http://en.wikipedia.org/wiki/Gear_ratio

I have a few other sources on gear ratios, gearing and tires if you'd like but you need to be more specific.

If all you're doing is changing your final drive ratio based on this change then I'd urge you to at least do some more research before you do that. I know competition is coming up VERY soon and that you probably don't have the time to change everything on your car...Maybe try to stick with your current wheel set-up instead of changing?

Cheers

[Spetsnazos]

I wrote a long reply but added a wiki link and I'm pretty sure its going to take forever to post...ugh

[Edward M. Kasprzak]

+1 to SamB for making an important point. Same to Missouri S&T.

+1 to Spetsnazos for being helpful.

In my opinion, both types of responses are important. Spetsnazos, nice response without providing a handout.

Although I feel these forums are sometimes too intolerant of posts like this IP, the resulting "carrot and stick" approach gets the message across. Let's just be careful not to overdo when using our "sticks". My two cents....

[thewoundedsoldier]

I wouldn't mind it so much if the grammar wasn't as obnoxious. And what kind of a name is choco-ball?

[Wesley]

While my reply was short and admittedly lacking any information, it really is that simple.

He asked how to determine the change in ratios due to the change in tire size. Fundamentally, the change in ratio is the ratio of the circumferences or diameters or radii.

Because the circumference equation is linear as a function of r, circumference is proportional to r. If you have a 1:1 drive ratio and you change your double your tire diameter, you double the torque acting on the hub from acceleration or braking thrust, effectively halving your final drive ratio and thrust capability of your engine. This is also results in unchanged HP delivery by doubling the linear speed of the tire (neglecting increased mechanical resistance due to higher tire speeds.) You reduce your final drive by a factor of two. This is where a tractive force diagram is really handy - not only can you easily determine your shift points, but you can figure out appropriate gearing so you aren't stuck in between ratios on a typical corner exit where you need maximum torque.

While yes, it is important to address geometrical considerations in the suspension when making the switch, that ultimately wasn't the question.

Now, if you are switching from 13s to 10s and need to figure out how to calculate the needed gear(sprocket) ratios to maintain your final drive ratio, a little more math is required. Since we're dealing with sprockets usually and not gears, the ratio is easy to determine (assuming you are not changing any transmission internals) by simple teeth ratios (unless you're getting into transient torque delivery caused by chain mesh, which I don't think is being asked here.)

[Edward M. Kasprzak]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I wouldn't mind it so much if the grammar wasn't as obnoxious </div></BLOCKQUOTE>

I agree. There is a place for text message spelling and grammar, and this isn't it.

I try to keep this perspective: We're still defining "social norms" to go with this new texting technology and language. It takes time. Cell phone ettiquite (talking on the cell phone) is much better now than when the devices first became popular--I think it's because we now have a relatively mature set of social norms defining proper cell phone behavior. Society more or less agrees on when/how it's acceptable to talk on a cell phone. We're still in the early stages of developing similar social norms for the use of text messaging language and grammar. It will be better in a few years.

And if the original post isn't a result of text messaging techniques spilling over, well...that's another story.

[thewoundedsoldier]

Haha who remembers typing into those 9-digit keypads?? Man the iPhone sure makes life easier...

I can't wait to get a device with Swype on it.