Mecanum Einstein this year

[AdamHeard]

Originally Posted by Ether

What was your rationale for the small wheels?

I'm thinking 1) less gear reduction necessary and 2) lower center of gravity

are there other reasons?

The question I always ask the people at competitions who question are small wheels is, "Well, why do you use big wheels?".

Usually the answer is either they don't know, or they always have.

We use small wheels for a lot of reasons, but they mostly stem from two of ours teams primary design goals; less weight, and less friction.

Small wheels are physically smaller, which is less weight.
Small wheels require less torque to turn to achieve the same force on the ground, less force in the shafts/sprockets means smaller and lighter parts.
Small wheels need less reduction, which is both a direct decrease in weight, but also a decrease in friction losses as we can run less stages of gear reduction total.
Small wheels let you have a slightly longer wheelbase for all other factors the same.
Small wheels are cheaper for us to make, as it's a smaller diameter stock, and has much less wasted material.

Also, experimental data has shown that for rough top tread, smaller diameter wheels have more traction.

To summarize, teams with small wheels usually have done actual engineering and reasoning behind their wheel size choice. Many teams with larger wheels do not (although some do, and decide to use KOP or other COTS wheels of a larger size for some logical reasons (like 111)).