Should you join a chain gang?

Originally published at: https://esk8.news/should-you-join-a-chain-gang/

The electric skateboard industry has been dominated by a number of different drive trains throughout the years. Hub motors have been very popular on lower priced boards predominantly in the prebuilt Chinese board market however there have been high performance hubs with varying success. Belt drive has been the go-to for many people both entering the esk8 world as well as those looking for a cheap and easy to maintain drive system. 

More recently gear drive systems have captured the attention of both enthusiasts and seekers of reliable low maintenance drive systems albeit with a higher price to match. For those looking for a robust drive system that falls somewhere in between belts and gears in terms of price to performance; another type of drive system may fill the role.

Enter chain drive. 

Let’s break down this system into its individual components. Chain drivetrains are typically designed similarly to common belt drive systems. The motor mount; well… mounts the motor to the trucks and provides the framework for the drivetrain as you would expect. 

Sprockets attach to the driven wheel and motor shaft and determine the gear ratio based on the tooth count ratios and link up the chain to transfer power. Last but not least the roller chain itself. This links both sprockets together and transfers power from one sprocket to the other and gives the drive system it’s name. 

There are both Imperial and Metric standardizations for roller chains and sprockets. Currently ones such as Metric ISO 06 and ANSI #25 offer a good balance of strength to size for mountain boards while urethane setups can often get away with something smaller.

Frequent light maintenance is an unavoidable caveat that can dishearten some. Once or twice a month I sit down to clean and lubricate the chain and sprockets with my trusty roommate’s toothbrush. During this time I also closely inspect sprocket alignment and verify all the bolts in the drivetrain are tight and secure. 

Long term maintenance involves replacing the chain if it has gotten knocked around in its lifetime from rocks and curbs and does not bend freely at each link. A chain breaker is important to have so you can select the appropriate length. I found my motor sprockets wear out considerably quicker than I expected so it’s not a bad idea to have a few spare as well.

You might be considering a chain drive setup for its high strength and an almost zero likelihood of skipping under power and overall robustness. These characteristics are ideal for high torque applications such as offroading and use in environments where debris like snow and gravel that could pose problems to ever popular belt drivetrains. 

The cost effectiveness must be stated as well because in general; chain systems are cheaper than gear systems and offer similar performance advantages. The simplicity and widespread use of the chain/sprocket design helps keep costs down, but as with anything there are boutique options for those with the desire and the cash.

The biggest issue of this drivetrain design goes hand in hand with one of its main selling points; it’s strength. With many chain drives designed open to the elements with high strength components there is ample chance for foreign objects to enter the system and contact moving parts and jam. I have experienced this a few times firsthand when a large object like a stick becomes caught up in the drive. This can be mitigated by protective guards akin to what you can find on bicycles, or positioning the motor at a higher angle from the ground to increase clearance from the ground in the “Danger Zone”.

Something which must be pointed out is that chain drivetrains are often very loud. While they can be well oiled every few days to keep things running quiet and smooth there will always be some remaining noise like the metallic zing you would expect from a chainsaw. Many like the auditory feedback loud machines give the operator though they may not be practical in certain environments such as your grandma’s cul-de-sac at 2am nor a major city in Germany.

Would I recommend someone purchase a chain drive system? As much as I want to answer “Yes”, I can’t as it is not the most practical decision. Having an open to the elements “unbreakable” drivetrain intended to be deployed in harsh conditions like what our mountain boards face on the daily is not as safe as intended. 

When something like a stick or small rock interrupts the rotation of the drive it is an immediate hard stop and in the real world these kinds of debris abound. I am constantly on alert for potential lockup hazards as I enjoy the wonders of modern technology. If you are looking for a bulletproof drivetrain for hazardous conditions I advise pinching those pennies in daily life and padding your wallet for that gear drive you’ve been eying.

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I would really love to see a fully enclosed chain drive for mountain boards. Fully enclosed belt drives are slowly apearing, Janux makes one and Boardnamics is working on one.
It would fall between belts and gear drive, would allow to put some oil in the bottom of the casing for continuous lubrication and would prevent hard stops from debris getting caught. Would also make it quieter.

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Great job, Joe!

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Good read, I wonder how the sound would change with an enclosed one. It would be quieter and keep debris out but at the same time you lose clearance, which is a problem for the big gear drives.

Interesting thought.

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Untitled

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Thanks for educating me good sir!

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@Saturn_Corp
Joe.
Maybe you would know or have had comments from people about this.

Efficiency wise.
Like rolling resistance.
How do you think chains compare to a belt system?

I run a #25 chain set up with 11/70 on my MBS set up. It has been good to me.

I just decided to convert the Haero from 12/72 on htd 5m 15mm belts which did some skipping over to 11/70 #25 chain.

I’m hoping to squeeze some more mileage out of the Haero.

I hope the chain is not counter productive to that…

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I doubt it would be counter productive to efficiency. It’s flinging around a bit more weight, but you should be able to run it looser than you have to run a belt to avoid skipping, so there should be less resistance. I’ve only ridden chain drive for a little bit, but I didn’t notice a big efficiency difference. Given, this was on thane.

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@rafaelinmissouri I honestly have no idea; here’s why.

While I have built one belt drive board I don’t feel I can compare the two well enough. For starters they were completely different boards. The Chain MTB with rubber tires and lots of power put to the ground vs a 40amp max Tayto on urethane with little power and no telemetry (that I didn’t really ride a lot). To truly know I’d have to swap the chains out for belts on the MTB @ the same ratio and change nothing else, even ride the same way. I have not done that but it would sure be something cool to try. Maybe one day but then I’d need new slightly-expensive wheel pulleys.

As of now I get about 30 wh/mi on the chains with my riding style, maybe 35 max.

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Here is my new chain set up.

Will update later how I do on efficiency.

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Chains 4 life!

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I know this is almost splitting hairs here.

But my last few rides the wh/mile is up.

Looking at 30 or 31…

So about the same I had before with belts…

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hi! just joined chain gang!! loving the strength for off-road!! however, i seem to have issues keeping the motor pulley from slipping after some miles (20-40) I started w/blue loctite, then red… happened again his morning :frowning: any advice?

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Are your motor shafts d shape, or round with a keyway? If the latter, is the sprocket secured with a grub screw or key? I’ve had grub screws back out on me even with loctite.

Always let loctite dry for 24 hours before riding it. I’ve made that mistake one too many times.

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The shaft is keyed, the sprocket does not have a keyway… it does have 2 grubs. i positioned one in the keyway and used red loctite on both and let cure for 36hrs

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Ok I get you. One of my boards has a similar problem but it’s a d shaft with a normal pulley and the grub screws back out a little sometimes.

My next idea would be longer grub screws if you can fit it in your sprocket. Perhaps having more threads engaged will keep it in if the ones there now are not already perfect.

I don’t know of any keyed-sprockets and have kept mine in place with grubs. Hope this helps, maybe someone else has some ideas

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Thank you!! That gives me something to try :slight_smile:

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Another idea i used on the torqueboards trucks was to use 2 grub screws on the pulleys. Insert one and tighten, then put another directly on top of that one and tighten. Locking grubs lol

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