Why are wheels so crazy heavy nowadays?

[meepmeepmayer]

At first glance, one thinks bigger batteries are to blame for the crazy heavy new wheels. But if you do the math, it turns out it's not the batteries. It's the motors and the rest of the construction! And it was always this bad.

Here are some example wheels:

• Abrams 44kg, of which about 10kg (only 23%!!) are the 2700Wh of battery
• EX20S 47kg, of which under 14kg (29%) are the 3600Wh battery
• V11 27kg, of which under 6kg (22%) are the 1500Wh battery
• V12 29kg, of which under 7kg (24%) are the 1800Wh battery
• S18 25 kg, of which under 4.5kg (18% OMG!!) are the 1110Wh battery
• S20 36kg, of which under 9kg (25%) are the 2220Wh battery
• Master 36kg, of which about 9kg (25%) are the 2400Wh battery
• Sherman MAX 39kg(?), of which under 14kg (36%) are the 3600Wh battery

This is depressing! If you're very lucky, only one third of the entire wheel weight is the battery. More likely, it's one fourth or even (way) less.

For comparison some slightly older wheels:

• RS 27kg, of which under 7kg (26%) are the 1800Wh battery
• 18XL 25.5kg, of which about 6kg (24%) are the 1600Wh battery
• 16X 24.5kg, of which about 6kg (25%) are the 1600Wh battery
• Nikola 26kg, of which under 7kg (27%) are the 1800Wh battery
• V10F 20.5kg, of which about 4kg (20%) are the ~1000Wh battery

This isn't even better!

Some really old wheels:

• ACM 20kg, of which about 6kg (30%) are the 1600Wh battery
• Msuper V3 26kg(?), of which about 6kg (23%) are the 1600Wh battery

It was never good

-

Do you think wheels could be lighter if manufacturers cared (more) about weight? Or is there some reason why the motors must be so heavy and the boards must be in heavy metal boxes and so on?

How could wheels be made lighter if it's not the batteries?

You can take away from this thread that battery weight has always been a constant (and low!) part of wheel weight. So the new, crazy heavy wheels aren't even as bad as one might think.

Or you can take away that manufacturers need to start caring about weight, because 40+ kg is not fun

-

(Big shout out to @AtlasP's wheel comparison table from which I took most of the weights.)

[Rawnei]

Could most likely make them both more lighter and more durable with more advanced materials but it comes at a cost both for R&D and prototyping into which materials to use and cost of materials, this would make prices go up and people are already complaining about the high prices so it seems like an impossible direction to go towards currently.

[EMA]

i can add some others data for you:

• when calculating info on begode wheels you should consider 4kg for the 900wh pack , so 8kg for a 1800wh
• c30 motor is 10.x kg
• c38 motor is 11.x kg
• EX c40 motor is 14.5kg 
• 16' motors are lighter
• 18' inner tube + knobby tire = 350g + 2200g = 2.5kg
• cst 1488 v11 tire is 1kg less than a c186 knobby or a kenda k340

some wheels are already into the best weight/performance ratio, best example RS and EXN

for other wheels we need to consider the addition features...

[Funky]

2 hours ago, meepmeepmayer said:

At first glance, one thinks bigger batteries are to blame for the crazy heavy new wheels. But if you do the math, it turns out it's not the batteries. It's the motors and the rest of the construction! And it was always this bad.

Here are some example wheels:

• Abrams 44kg, of which about 10kg (only 23%!!) are the 2700Wh of battery
• EX20S 47kg, of which under 14kg (29%) are the 3600Wh battery
• V11 27kg, of which under 6kg (22%) are the 1500Wh battery
• V12 29kg, of which under 7kg (24%) are the 1800Wh battery
• S18 25 kg, of which under 4.5kg (18% OMG!!) are the 1110Wh battery
• S20 36kg, of which under 9kg (25%) are the 2220Wh battery
• Master 36kg, of which about 9kg (25%) are the 2400Wh battery
• Sherman MAX 39kg(?), of which under 14kg (36%) are the 3600Wh battery

This is depressing! If you're very lucky, only one third of the entire wheel weight is the battery. More likely, it's one fourth or even (way) less.

For comparison some slightly older wheels:

• RS 27kg, of which under 7kg (26%) are the 1800Wh battery
• 18XL 25.5kg, of which about 6kg (24%) are the 1600Wh battery
• 16X 24.5kg, of which about 6kg (25%) are the 1600Wh battery
• Nikola 26kg, of which under 7kg (27%) are the 1800Wh battery
• V10F 20.5kg, of which about 4kg (20%) are the ~1000Wh battery

This isn't even better!

Some really old wheels:

• ACM 20kg, of which about 6kg (30%) are the 1600Wh battery
• Msuper V3 26kg(?), of which about 6kg (23%) are the 1600Wh battery

It was never good

-

Do you think wheels could be lighter if manufacturers cared (more) about weight? Or is there some reason why the motors must be so heavy and the boards must be in heavy metal boxes and so on?

How could wheels be made lighter if it's not the batteries?

You can take away from this thread that battery weight has always been a constant (and low!) part of wheel weight. So the new, crazy heavy wheels aren't even as bad as one might think.

Or you can take away that manufacturers need to start caring about weight, because 40+ kg is not fun

-

(Big shout out to @AtlasP's wheel comparison table from which I took most of the weights.)

Wanted to fix a BIG, BIG mistake 18xl isn't 25.5kg, it's 24.5kg <3 (It became 25.5kg, when i put on K66 tire. )

There's also that all these "new" wheels are so big = more material = more weight.. I love how small ks16s, 18xl are.

Edited March 21, 2022 by Funky

[meepmeepmayer]

2 hours ago, EMA said:

18' inner tube + knobby tire = 350g + 2200g = 2.5kg

2.2kg for only a tire?!

If you say it I believe it but...phew

[RagingGrandpa]

2 hours ago, meepmeepmayer said:

How could wheels be made lighter if it's not the batteries?

Well, we still want our EUC's fast and powerful, so we're gonna need copper. There's no way around it.

I think the most mass-efficient formula for a 40mph-capable EUC with > 2kWh is Nik AR. Smaller rim, smaller tire, plastic body, and still all the powerful guts. 
NikAR is another standout in terms of mass... assuming the 2700wh packs total 10.3kg, that's 35% battery by weight, same as Sherm.

But if the weight isn't in the body, and also not in the pack, then it's in the places it matters- the motor, tire, and rim. Don't skimp on those. 

 

Edited March 21, 2022 by RagingGrandpa

[BKW]

I like how some of the wheels are heavy. Good for stability and harder to steal. But then again, I don't own a heavy wheel yet.

[RagingGrandpa]

1 minute ago, bkw said:

I like how some of the wheels are heavy. Good for stability and harder to steal. But then again, I don't own a heavy wheel yet.

Mass is bad. We're stuck with it, so it's something we live with... 

A Sherman at 35mph over bumps is much much more difficult to stabilize as a rider, than an MSP, with the same tire, at the same speed, over the same bump.  

[Funky]

17 minutes ago, meepmeepmayer said:

2.2kg for only a tire?!

If you say it I believe it but...phew

Original tire CST C-1488 18x2.5 is (1050grams). K66 80/80-14 is (2080grams). So basically it's 2x the weight. Also a lot thicker. Sidewalls alone are 5x thicker. Surface is around 2x thicker. < Amazing tire doh, love it.  

[.....]

Batteries and motors arent made of thin air. As far as current tech goes, I think they are about as light as they can be. Until we see improvements in battery and basic electric motor efficiency, weight will remain. Look at the weight vs specs of the little 67v mten. Even that little thing has some heft to it.

[Funky]

1 minute ago, ShanesPlanet said:

Batteries and motors arent made of thin air. As far as current tech goes, I think they are about as light as they can be. Until we see improvements in battery and basic electric motor efficiency, weight will remain. Look at the weight vs specs of the little 67v mten. Even that little thing has some heft to it.

Doh riding one i fill like little fairy, gliding true air.  It's so magical. 

[EMA]

32 minutes ago, meepmeepmayer said:

2.2kg for only a tire?!

If you say it I believe it but...phew

exactly  not everyone consider that 

C1488 18x3 is 1.3kg super soft and thin, it last 5000km max in a decent shape
any kind of  80/90-14 is 2.2-2.3kg , superior quality and 10000km easy

22 minutes ago, RagingGrandpa said:

Well, we still want our EUC's fast and powerful, so we're gonna need copper. There's no way around it.

I think the most mass-efficient formula for a 40mph-capable EUC with > 2kWh is Nik AR. Smaller rim, smaller tire, plastic body, and still all the powerful guts. 
NikAR is another standout in terms of mass... assuming the 2700wh packs total 10.3kg, that's 35% battery by weight, same as Sherm.

But if the weight isn't in the body, and also not in the pack, then it's in the places it matters- the motor, tire, and rim. Don't skimp on those. 

 

nik+ at 30kg is best weight/power ratio
EXN is 32kg due to motor and tire

[RagingGrandpa]

2 minutes ago, EMA said:

weight/power ratio

Uhoh, hopefully you don't take the "motor power ratings" seriously?  

(The rider feels force, not power...) 

Edited March 21, 2022 by RagingGrandpa

[mhpr262]

One could use much lighter, high revving outrunner or even inrunner electric motor instead of the heavy hub motor if one used gears, or a belt with a high reduction ratio to drive the actual wheel. Unfortunately I dont think that it is possible to build such a transmission that is rugged enough to withstand even normal use over thousands of kilometers, much less jumps and stunts. It might work if one exclusively rode on smooth asphalt roads.

[Whalesmash]

Hollow bore motors are generally heavier than their standard axel counterparts. Add in suspension components and you're taking a hit on the power to weight. The EX is probably the worst offender with its massive motor and tremendously heavy steel/whatever-alloy-they-use suspension components. I think the motor/suspension components alone weighed more than my entire S18 when I took the wheel apart for a tire change. I honestly thought I forgot to disconnect the motor wires or something with how much effort it took to pull the motor and suspension out of the plastic carcass.

[mhpr262]

Axial flux motors ought to offer a lot of potential when it comes to reducing weight. You wont get much more power out of them because the bottleneck are the batteries, but the same power and torque at a much lower weight and possibly with slightly increased efficancy would be a nice bonus.

Edited March 29, 2022 by mhpr262

[alcatraz]

9 hours ago, Funky said:

Wanted to fix a BIG, BIG mistake 18xl isn't 25.5kg, it's 24.5kg

That was a close one! 

Weight has always been a concern for me. I'll stick with my 23kg MSX and 19kg Tesla. If you cap them at 40km/h you're pretty darn safe. I made the mistake of trying to get speed out of a lightweight wheel. Don't ever do that. 

Priorities

1. Speed/power margin

2+. Weight

[alcatraz]

8 hours ago, mhpr262 said:

One could use much lighter, high revving outrunner or even inrunner electric motor instead of the heavy hub motor if one used gears, or a belt with a high reduction ratio to drive the actual wheel. Unfortunately I dont think that it is possible to build such a transmission that is rugged enough to withstand even normal use over thousands of kilometers, much less jumps and stunts. It might work if one exclusively rode on smooth asphalt roads.

Rockwheel used to use internal gears. Their wheels could climb inclines no other brand could climb. I wonder how reliable they were... The later released wheels without the gearing so I'm guessing, not good.

[InfiniteWheelie]

I have the Sherman and I don't get the weight complaints. When riding I'm pretty sure I wouldn't want a lighter wheel, it adds stability and traction. The weight has never seemed like a negative when riding. When lifting it sure, but it's totally manageable for me.

Edited March 22, 2022 by InfiniteWheelie

[alcatraz]

1 hour ago, InfiniteWheelie said:

I have the Sherman and I don't get the weight complaints. When riding I'm pretty sure I wouldn't want a lighter wheel, it adds stability and traction. The weight has never seemed like a negative when riding. When lifting it sure, but it's totally manageable for me.

Depends where you live. I sometimes have to get on public transportation or cross very busy places. (dense city living)

[BKW]

49 minutes ago, alcatraz said:

Depends where you live. I sometimes have to get on public transportation or cross very busy places. (dense city living)

If you're getting the sherman for portability then you're looking at the wrong wheel. In that case, get a more portable wheel

[EMA]

13 hours ago, RagingGrandpa said:

Uhoh, hopefully you don't take the "motor power ratings" seriously?  

(The rider feels force, not power...) 

absolutely not

i should have written weight/performance 

[meepmeepmayer]

7 hours ago, InfiniteWheelie said:

I have the Sherman and I don't get the weight complaints.

This is true. No wheel feels heavy while you are riding it. And some weight might be nice to get stability.

But you feel the weight when you are not riding, and I wonder if wheels couldn't be a little lighter without any downsides when riding.

[EMA]

you always feel the weight, it affects dinamics a lot, with time and skill you get used to it but basically is a trade off if you want range and so on .

no one will add weight on a wheel to add stability
 

[meepmeepmayer]

Let's try a different approach:

If your high-speed, high-range wheel could have any weight you wanted, which weight would that be? So that it still is stable etc.

20kg?

25kg?

30kg?

More?

Would you want different weights for offroad and on-road riding?

Is there a perfect weight for a performance wheel, or does it depend on what you want to use it for?

Edited March 22, 2022 by meepmeepmayer