When it comes to building your own electric skateboard you get to decide how it performs. So do you need two motors or is one enough?
Having 2 motors is amazing when everything works perfectly. I’ve personally found it easier to maintain a solid rig using 1 63mm motor. Especially if it’s your first build, or you only have one board. A single 63 with an 8s lipo battery will achieve 6-8hp. That’s plenty of torque to climb hills or power you to speeds in excess of 40mph. Also, you’ll only need 1 ESC, 1 motor mount, 1 set of pulleys, and 1 belt.
All of that said, a more complex build with 2, maybe even 4 motors, is fun to ride and always great to see.
I remember planning my first ever build… I really wanted dual motors but just couldn’t afford it. It was going to be about $300 more to setup dual drive VS a single drive…
In the end I was lucky enough to buy some second hand spare parts at a pretty good deal which allowed me to build a dual drive within the budget I had set.
To this day I have never built a single motor board. I have however ridden my dual drive with one motor disconnected (due to it shorting out & catching fire) and it felt way too slow … I think you get addicted to the huge torque of a Dual Drive …
But it is also worth noting that I was only running 50mm motors, the NTM 5060 Propdrives…SO a bit small for me considering I weight 95kg. So I think if you are going to build a single motor board you definitely want to go with 63mm motors and as big/long as you can physically fit onto your board. I think Minimum 6354mm Size motors for single motor boards.
But it also depends on your weight, if you weight 50 or 60kg you could probably easily get away with smaller motors.
my mantra these days is OVER ENGINEER EVERYTHING!
This is the main question everyone asks. I always recommend dual motors especially when going uphill. More then anything it’s less stress on one motor and always much easier on the motors going uphill which equals a much less chance of repairing your setup. This allow users to make much more mistakes on their setup (Ex. Wrong gearing ratio, heavier rider, etc.) I’m able to effectively climb hills in San Francisco with a 20-35% incline. Sometimes, the inclines and hills I ride up are pretty scary to ride in the first place.
However, I also suggest a single motor setup for mainly flat ground as it’s much less stress than climbing hills.
I think it also depends on the type of wheels and also terrain you plan on riding. For instance if you are building a board and plan to use pneumatic wheels and maybe ride on long grass or dirt trails I definitely think you want dual drive.
Pneumatics wheels don’t roll as efficiently as Urethane, so you need more torque!
There are two ways to get more torque, change your gearing ratio at the cost of top speed - which you can supplement with higher voltage, or add more motors.
I think it is also worth noting that the handling performance of your board will also be impacted by your motor set-up. If you do just have a single big motor you might have some torque steering issues during acceleration & braking.
Maybe some evolve riders should give some feedback… I have heard several evolve owners talk about torque steering being an issue.
But once again if you weigh 50kg its still probably not an issue as one motor has less load to push.
i have a dual drive system and i’m pretty addicted to the torque and top end speed you can get from having twin motors. Not to mention the benefits of added braking power. I’ve done some experimenting on my 6S board and have run it with 245s and 270s, and have run single and dual drives.
I’m not the biggest guy, so i can probably get a little further than some on the same setup. Despite that, here are my findings on 245s and 270s in single and dual configs on a 6S board that weighs about 18 pounds on its own with both motors and 155-160 pound guy riding it:
Enertion 245kv in dual motor config:
Torquey as all hell. I failed to notice hills, acorns, sticks, small children, dogs, or even transition dips in sidewalks. I felt them in my wheels, sure, but the motors didn’t seem to care what was goingon, they just kept pumping out power. Top end got me up to about 27-28mph on flats. Crusising at 15 to 18mph was very comfortable and smooth. Braking is nice and stiff, so watch it.
NTM Propdrive 270kv in a dual motor config:
Just a barely noticeable drop in launch torque over the 245s, and i mean barely noticable. However, they do run hotter, so they may not last quite as long overall if pushed hard consistently over time. Also they aren’t keyed so they’re somewhat inconvenient to build with. And they cog harder so push starting is not as fluid as the Enertion 245s. They really shine on the top end though. I’m currently using them and have achieved speeds above 31mph. Braking is still nice and stiff.
Enertion 245kv in single motor config:
Still pretty torquey, but a noticeable drop in launch Gs. I have to admit riding around on just one of these wasn’t bad at all. Of course it didn’t quite conquer the hills with the same rage ad prejudice the dual set up did, but it got me there in a manner i was good with. And just cruising on flats and sidewalks at a sane speed was every bit as pleasant. When one of the motors failed during a more restrained casual cruise, i barely noticed it. The other one picked up the slack and i didn’t realize anything was wrong until braking, which is not all that stiff on one 245. top speed on a single 245 for me was around 25-26mph. I noticed more torque-braking than torque-steering, per se, but there was a little bit of the steering issue as well. But once you get used to it, its not so bad.
NTM Propdrive 270kv in a single motor config:
You can really feel that second motor missing during take off. Once you get going though, acceleration gets a little more of its oomph back, but not much. Casual cruising is decent and pretty similar to the 245s. Top end was around 27mph for me. Braking was mushy and slow and you could again feel the steering being affected by it. But overall, still pleasant.
Are any of those motors 63mm?
Nah all 50mm.
the NTM propdrives are 50mm, I actually thought they where a pretty good motor for the price.
The old Enertion R-Spec 245KV where 50mm D x 60mm L
The new 2015 R-SPEC are all 63mm D x 55mm L
Early on In my product development I was always trying to keep the weight as low as possible, power to weight ratio mantra…
But now, When it comes to motors at least, My theory is simple: bigger is better.
But I’m a serious torque junky.
Yeah sorry those are all in a 50mm package. I don’t have as much personal experience with 63s yet, but i’m looking forward to seeing how they ride. I’m also interested in trying some 200kv 50s.
Maybe @torqueboards can write an article about his new 50mm sensor motors!
They’ve just been sent out recently so I should be receiving them soon. I can’t wait for the longer extended motor shaft as well as the sensored aspects. Using 15mm belts are pretty awesome. I try to switch to 9mm again but it’s hard because there’s much more responsiveness with 15mm versus 9mm and no belt slip on 15mm.
However, it’s much more difficult to run a dual rear setup. I do wish I got 63mm over the 50mm. Especially, for single motor 63mm is a better option depending on the gearing ratio. I do believe in onloop’s idea of over spec on every item but with that can also sometimes come added weight. For dual rear 50mm’s are more then fine. Single 50mm lacks going up 30 degree inclines. Flat’s is fine though.
I think if you are going to be attacking lots of hills the climbing advantage AND braking advantage of duals is essential. I had rode single for a long time while I worked the bugs out of a dual setup and it worked great but as torqueboards suggests, I was fighting heat with that single motor and there were a few hills I could not attack.
Now with dual I can go up and down almost anything with the exception of 4 local 29-31% graded streets.
Maybe need 4WD for those “mountains” - and maybe a jet pack
dual motors are a must have for hills, or heavy riders.
My local area is mostly flat and I am a small guy so I enjoy the extra range of my single motor deck, but I took it through some hills the other day and it struggled. the dual motor board just eats them up.
(unfortunately it also eats up batteries as well)
I guess I’m lucky I live in a relatively flat area. but it goes to show that there is no real “one size fits all” solution with electric skateboards. I will happily forgo the extra motor for a longer range because I don’t need the power. where as some of my other friends really need that extra power.
having said that, when the batteries do eventually run out the single motor is a lot nicer to kick push because it has less drag than the duals.
also novice skaters tend to need dual drive a lot more because of their cautiousness. the low down torque helps them move about slowly.
because I skate fast even without a motor I am able to use my momentum to cover small hills on a single where as some of my novice mates need the dual because the are a bit scared to go too fast and cant carry the same momentum.
so like I said. no “one size fits all” for me personally single does the job.
pros: lighter, cheaper, longer range, less drag.
cons: less torque, less drive surface.
I only recommend dual motors if the person plans on climbing 20-30% inclines and it’s about 20-40% of their route.
I’m actually going to setup a single motor 6374 on 10S?12S and see if it’s enough power to ride my daily route. I’d say about 30-40% of my route is uphill a 20% incline if not more on some parts.
If your weight is greater than 90kg I think dual is also worth while.
A post was split to a new topic: Weight vs Speed: doing math for electric skateboard builds
What about 325 lbs and mostly 15 - 30 % grade hills would it even be worth trying?
It’ll depend on gearing and your setup (kv, voltage, etc.). I’m not too far off from you (265lbs/120kg) and ride even my single motor setups on the flats just fine. The killer is hills. Gear down, and the easer grade should be doable. Might need to walk up a few though. And a running start always helps!
I"m planning on 1 or 2 245 kv motors with 22.2 V for single motor to 44.4 V double motor with a gear ratio 8:24 which for single motor would give me 29.035 ft lbs single and 58.07 ft lbs double. that give me a thrust to weight ratio of .08 to .17 what i’m wondering is what is the thrust to weight ratio you are experiencing?