Max-Speed vs. Hill-Climb Charts

The Evolve-Guy made a video going up a 30-35% hill with a Carbon GT

He used 80mm wheels and the 38t Drive-Gear to get max torque. With this setup the max speed of the board is reduced to below 30 km/h. I made a few charts to show how much of a hill you can go up with different gearing und what power is needed:

Watt is the power the drive-drain have to handle at your hill-climb-speed (huge amp draw), not max motor power at full RPM

And the next time you see a random chinese board claiming insane precs, throw them against these charts to prove them wrong :wink:

This may also help you with gearing/motorKV-decisions

Calculation is done with this:

the Evolve-Video:


This is, in fact, the steepest hill in the world. Located in New Zealand. I watched the video. They went up the steepest hill by moving curb to curb near the top of the hill. That’s not the same as going in a straight path.

Edit 1: OP has a typo. What do you mean 30-30% hill grade? Baldwin street has a 35% grade.

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Nice info you have compiled…

Takes a bit of time to understand it… but after a while it gets somewhat reasonable I think…

Someone know could take a vesc monitor app and do some field tests with this data… :smiley:

though 3-4kw for reasonable speed and hill climb sounds reasonable.

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yes, this is pure theoretical, verifying this with real data would be great

Good post. You mentioned, “38t Drive-Gear to get max torque.” This is a topic I wish more e-skateboard makers would include and talk about. Where can I find more information and learn about “drive gear ratio”?

It should be noted a person’s setup to get max torque will be a result of a battery pack, motor, and wheels chosen.

An automotive book about gear ratio and final drive ratio should give you a basic understanding although it’s complex. The important point is taking what you learn about choosing gears for higher Top End or higher Acceleration/Low End Torque.

Good answer. Thanks Chuttney1. You’re helpful.

I don’t want to be a genius. I just want to know enough to be a smart shopper. I’m surprised electric skateboard manufacturers don’t have this information easy to look-up and understand.

There’s huge fast-growing interest in both Seattle and San Fransisco of daily commuters looking for a last-mile high power board that can … (1) handle a few steep city hills (2) carry healthy adult-size weight with a laptop backpack (3) safely power-thru wet sidewalks and wet streets

Board makers could sell a lot more if they explained a little physics inside their products with detailed specs so buyers could make a smart choice. Right now, a lot of consumers won’t buy without knowing more facts. … I think manufacturers should explain things the way you do! :slight_smile:

I don’t say this to be a dick, so please don’t take it that way. The info is all here on the forum, just gotta search. It can explained all day long but noone can make you understand. You just have to dig in and keep reading until it clicks.

I’m actually a bad at explaining concepts. Takes me longer to explain something that can be said in a shorter amount of time. What mmaners says about this forum is right given there is plenty of information of other’s people’s build. So you have to use the search function to get a well round idea of what gear ratio you want to use for hills of a slope. I answers because no one gave a response.