Chain drive or Gear Drive or Direct Connect?

I am looking to replace and fix my drivebase. Currently we keep swapping out the gears in remodeling. I was wondering if a Chain drive will work better with gears in the rear to make it like a 5:7 ratio with the chain to connect to the front.

My robot currently has 4 motors, geared weirdly because of lack of understanding. Would a direct connect motor system work better?

chain is the worst option, because if it snaps your robot becomes completely useless.
if you want to have a ratio gears are the best option, and gears are also a way to move motors out of the way of the front or back ends of your robot which you might need clear for other mechanisms.
direct driving your wheels isn’t bad, though it prohibits having much control over your ratio or your motor placement.


Then will speed be good for this game? And should I keep all wheels omni or swap a pair for more control.

we have had chain drive for 3 years now and it has only snapped once, the key is tensioning the chain with stand-offs to keep the chain at the perfect tension. (the one time was during stress testing the base the first year)

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What about with the snapping? Isn’t that caused by changing direction fast. Like forwards then whipping back.

they break from the tension of driving, switching directions increase the risk of it breaking by increasing the amount of tension on the chain for that moment, but if tensioned right, it should not break that easily

We have had chain for the same amount of time and it has not snapped once.

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As a general rule, speed is good for every game. If you can do something faster than your opponent (even if not as accurately), you put a lot of pressure on them.


While this is true, I used chain for the entirety of last year and didnt have a single snap despite aggressive driving.

If you do chain, make sure at least one set of wheel is directly connected so that the bot can still move even if the chain breaks.


How much tension is too much? Is that trial and error?

Our team uses gears with a 5:3 ratio for 333 rpm and it works really well.

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Along with that, Can I add more motors to it? Would that increase speed or should I get a gear system hooked up then sprockets connected to the wheels. Or do you use a Large sprocket then a small one for the connected one to the wheel?

I’ve only used gear drives, for 6 wheels with 2 motors which was 1:1, lets just say we wheelied a lot 3 years ago.

with chain, you could theoretically have infinite motors
but with real-world and vex constraints i would not go over an 8 motor drive
as long as you keep the ratio constant you should be ok
I would just do 4m drive and individual chain systems to go to each wheel
but you can chain a whole side if you want, the downside being if one blows it all blows whereas chain to each wheel separate just slows down a side

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For tipping point, speed is a massive advantage. Keeping your robot light, fast, and maneuverable will make it a lot easier when having to defend as well as score. As for the wheels, my recommendation is that for a standard tank drive you should use high traction wheels in the front and Omni in the back as it allows for the best combination of speed and maneuverability. All Omni increases turning but will also slow your robot down. These are the wheels I recommend in the front:

while the risks of chain snapping might be low, I’m not willing to take the risk that my drive will spontaneously break during an important match, even if that only happens once or twice in the whole season. I place reliability above all other things, and gears are just objectively more reliable than chain.

the only time I would ever recommend chain on a drive is if all your wheels are direct driven by a motor, linking each side with chain will allow you to always have full power even if the 2 of the wheels are removed from firmly contacting the ground somehow. and if this chain snaps, it doesn’t disable your drive, just might make playing defense or climbing mildly harder.

gears also have other advantages, such as the lowered slop


I have had a gear drive ruin more gears than I have had a chain drive snap, but to be fair the gear drive was the first drivetrain I had ever made. In my opinion, gear drives are a lot more annoying to make and repair.

At the end of the day it is all up to personal preference, I like the chain drive, but @Xenon27 likes the gear drive. are any of us objectively wrong or right? No, there are many times gear drive is superior, and many times chain drive is, it just depends on the robot,


I’ve had a chain drive for the past 3 years, however thos year we have switched to a 6 motor geared to 360. This has proven to be very reliable. All of these years we have used a 4 omni setup. This gives maximum mobility without going to a meccanum and is a dream to code.

What is the best way to transfer power?
  • Gears
  • Chain/sprocket
  • Belt drive/pulley

0 voters

If you choose belt drive/pulley you are objectively wrong.


Not for anything really really high speed

Gears are best, but sprocket is best for drivetrains and long distances