The Racers Room

I have a question. I think this stems from my lack of understanding about the dynamics of radius and how it applies to rotation, anyways here it is.

Why doesn’t a 150mm wheel (pneumatic) with 60T pulley go faster than a 100mm wheel that’s thane with a 36T pulley? Is it the gear ratio? I think it is, but If so why not use 36T pulleys on 6in wheels?

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@mmaner Yes, its the gear ratio. Assuming you’re using the same motor pulley (let’s say 12T for this example), 3 motor turns would equal 1 turn of the 100mm wheel whilst the same number of motor turns would provise 60% of a turn for the 150mm wheel. 60% of 150mm wheel is 283mm whilst a full turn of a 100mm wheel is 314mm. The same number of turns, in the same time covers more distance so the 100mm wheel must have travelled faster.

I’m not sure why people don’t use 36T pulleys, perhaps since 6in wheels are normally used for mtb, they want more torque rather than top speed?

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Thats prolly it, I really like AT wheels but for the comfort level and the fact that I don’t have to pay as much attention to the surface directly in front of me. But nothing beats the feel of thane on fresh asphalt.

I might have to print some 36T or 40T pulleys for my @psychotiller 6 Shooters and see how fast I can bust my ass :slight_smile:

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You would have really bad torque and crazy top speed with 36t and 150mm wheels. It doesn’t work well.

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I have 42t pulleys on a board with six shooters. 40mph.

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That might be the way to go then, I’m just testing for my own experience so no big f it doesn’t work great. As far as racing is concerned, do most people use thane or numies?

On the Asphalt, on a course, Pneumatics are king. It would be a different story though if the course was opened up distance wise.

Order these: 42t x 18mm Wide VersaPulley Kit (HTD 5mm, VersaKeys)

https://www.vexrobotics.com/htdversapulley.html

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will do, thanks brother.

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I noticed a significant decrease in Tq going from 16/36 97mm to 18/36 107mm. Still powerful acceleration with dual 6374s @190kv though. I still need some hilly areas to test ability to climb. It’s flat where I live by the ocean.

Dropping that many teeth on pneumatics would be for sure noticable.

@MoeStooge @57mph what was the difference between current and motor current. Plenty of drag at that speed.

Yeah how many amps were you pulling Bro? did you get the data log? @E1Allen Moe is on 200a hobby esc’s so his parameters are diff. to a vedder…

Ah. Did not know.

Not sure if I will have data logged, will look later. Can tell you neither the esc’s or motors built any significant temperatures.

Pneumatics are king on your mom.

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They are king on everyone’s mom🏁

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how about your battery pack, were you noticeably draining it at the speed, were you on the charger all day or was the 36ah or what ever you enough to make that a non-issue?

to many questions, would have killed to be there… boy and tillers moms were stooge groupies

LHB’s mom draining it at speed! Now there’s an event!

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Took about 30seconds get up to speed and not break traction. Could hear Chuck’s turbo Cooper working hard to follow. 8000mah 8s made 6 hits, last hit of the day was a tick over 30v before the run.

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oh damn tiller’s moms backing up everybody step back

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Difference between everyone’s mom and a lightbulb? You can unscrew a lightbulb.

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One of the early passes from the day. Didn’t know how the dirt would hold so we proceeded with caution. https://youtu.be/yjdB-D-TTIE

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