They will both have similar rolling resistance since most of the resistance is from the motor not the belt/chain.
Unless of course your belt or chain is way too tight.
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Thank you!!
I toyed with the idea of having a freewheeling cog - something with pins in it so you could pop the pins out and use it as a regular board. Mostly I wanted this when my board broke down and I had to push it home. Lately they’ve been pretty reliable so this dropped off the list.
If I ever get back to working on the 2-speed transmission I might add freewheeling in as part of that.
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Do you have any renders of it? I’m really curious of how that would look and work. Have you considered a CVT since there is no switching of gears to drop power. Also it would automatically switch according to rpm.
I don’t - my first run at it was a total failure so I shelved it.
But my idea was to do it the same way a motorcycle transmissions works - with little balls in the driveshaft and the shift rod has an indentation - so when you move the shift rod it engages/de-engages different gears. It would be pretty easy with a 2-speed, which is all I want. I just need something that allows me to climb hills without having to add the weight and complexity of a second VESC/motor.
I think you’d have a lot of mechanical losses with a CVT but I’m happy to be proven wrong. Also, I’m not sure how a garage-tinkerer would build a CVT.
If a group of us wants to get together and design something I am happy to contribute both ideas and CNC/gear cutting/mechanical time.
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I think this is a great idea ! You have really pushed this forward (technologically) for us on this Esk8 builders forum!
Do you mind start collecting similar minds? There was thread about CVT’s, though Im not quite sure how many are willing to participate! As of right now I dont have much CNC experience nor I can freely share any material resources to help anyone! I think just a plain forum support would at least push it 2-3% this idea in the right direction…
On a side note - Could you describe the operation of how gears would be shifted with your described method?
I did not quite catch will you do it with a little rod / lever or not.
I assume this would be purely for hills - before a big hill, you stop, switch to a higher gear ratio, ride up a hill, then stop, switch back to the ‘‘normal’’ gear ratio and continue riding. (Not sure how practical this might be, but might work if you have more than one hill in a row and the rest of the trip is flat… )
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@Okami, this is a great video on how motorcycle transmissions work. It does not use the same shifter system as I described (which was on a Hodaka 99cc dirt bike from the 70’s) but it’s the same principle.
So designing a 2-speed transmission with a neutral in it would be pretty easy (relatively speaking) based on copying this design but with only 2 gear sets.
I envisioned using a solenoid to shift from one gear to the other - you wouldn’t have to stop you’d simply have a button on the remote for low gear and high gear or you could have your controller detect a low-speed/high torque combination and shift automatically. That would also eliminate the need for push starts before engaging the motor since you’d be in low gear at stop.
For extra credit you could have the controller do speed matching of the motor and the wheels during shifting to avoid the clunk since we wouldn’t have a clutch. But since the motor has so little rotational mass I would think a quick depower before shifting would probably suffice.
Having a stepped solenoid that included a neutral would be a bit more tricky but it would be pretty slick to be able to kick the thing into neutral from the controller when some feature came up that you wanted to freeride.
Depending on how my other projects go I might have some time to look at this in the spring.
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Also, I looked at CVT’s a little bit - this is a good video on how they work. You can see that if you use a belt-style CVT you’d have a lot of losses because of the tension against the belt.
There are some more advanced designs, but that’s where the complexity vs. garage-tinkerer issues comes in play.
Lots of good points have already been made here but I thought I’d throw my opinion of cost in. I’ve seen a lot of people saying chain and sprocket costs more us front. I just purchased 3 feet of #25 chain, two 11 tooth sprockets, and two 30 tooth sprockets to drive my dual diagonal board all for $32 total after shipping (shipping was free). So just saying, it’s not necessarily cheaper to go with belt and pulley. Plus I’m willing to bet other replace their belts more often that I’ll replace my chain 
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I went with a chain drive too, for me it was the only choice as I wanted durability and strength. My parts cost less than £20 and I have a spare, slightly smaller sprocket, and loads of chain left over.
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oh shit, youre running 3dm avilas!!! 
Cant you put a cover over the belt/chain like who the timing belt on a car is covered.
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I always hear people say how chains get dirty and have to be oiled and are louder etc. I know from bikes and videos of chain drive boards that theyre not that different from belt in terms of noise. The chains can be covered, thereby resulting in them never getting dirty. Bikes are typically oiled every few hundred miles, which is just putting a bit of oil along the chain so I dont think it would be too different for this. The only remaining issue with chains is the parts wearing out, which I don’t think would happen more than once or twice a year at worst.
My current board hits only around 18mph at top speed and yet the belt feels like it can barely handle that and skips teeth if trying to accelerate hard or break fast. The first one broke in like 2-3 months of light occasional use. I ended up spending $20 to get a good quality one to see if it made any difference but it feels the same. The board I’m building will be hitting around 30-35mph and I’m just not sure if I’d trust belts at those speeds.
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You UK based mate? Where’d you get your parts from?
Yeah in Essex mate, you?
I can’t remember exactly but all links are on my blog 
http://kevindark.co.uk/Blog/Read/7
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Up north in newcastle 
I’m keen on having chain since im 6,3 and 85kg so I get soooo much belt slip and shredding!
I looked at your blog there, you’ve done a nice clean job. Seems like you have access to a few tools I dont, would it be possible at all for you to sort me out with drilling some holes in sprockets etc? Bolts for the wheels, and a grub screw on the motor pulley (if there isnt one)
PM me if you get a chance i’d be grateful
Cheers
Thanks, I tried, although now it looks a lot more beat up! lol
Hmm I don’t mind doing it to be honest, but I couldn’t say exactly when I’d have the time to do it, I’m just so mega busy lately. For the holes in the sprocket (for the bolts) you could easily just do those with a cordless drill, the same with the holes through the wheels, although you may not have to do that depending on which wheels you get.
The pinion you get should come with a grub screw hole pre-drilled, not sure why mine didn’t, just a mistake I think.
The rest of it I’m sure you could do with a handheld drill.
Haha fair enough mate! Yeah ill look into it. Im a student who lives away from home so im fairly limited in my inventory, might get some stuff ordered so that next time im at my dads i could use his garage. The pinion would be fine if it came done yeah, will have a think. Cheers though appreciate it