My advice for chain longevity is you never want to use a big chainring into a small cog, in a bicycle grade drivetrain torque is your enemy. You want as much overdrive as you can muster from the motor in a gradual fashion and let that final cassette cog transform all those sweet RPMs you've accrued into gut wrenching torque to get you out of the dig in a rush. If you need to use the 11T to achieve top speed then you are using the wrong gearing.
For normal road going conditions and light offroad you want to use... say, a 52T chainring into a 36T cassette cog or a 42T cassette cog, or even a 49T or a 50T if possible BUT all made out of steel. You want to stay away from alloy in the drivetrain, just use steel; and if you can get CroMo components (chainrings, etc) get so as well.
My recommendation for gearing for an eBike in the 60lbs range would be a 18T motor freewheel into 48-52-24, a 18T into a 48T drive chainring, then a 52T to cassette (use the 24T for very steep hills to keep motor RPMs high); use a 10 speed 11-42 cassette from Sunrace, and get the ALL STEEL one, don't fall for the alloy crap one...in 7k miles I've gone through 2 of them, they will last a very long time if geared correctly. (in excess of 5000 miles each.) The Wolftooth cog on the other hand, didn't last much, so its useless for high power eBike long term application.
If you want to derive your own gearing, then first what your cruising speed is going to be and make sure you hit that speed in 2nd or 3rd gear (3rd gear being at least 32T). Don't bother using anything under 28T on the Cyclone for an extended period of time if you expect longevity; small cogs will eat chains, skip teeth, bend parts... etc.
So, with that said, if you first think you are going to cruise at 20 mph but you end up accelerator happy and you end up all the time stuck in the 11T then you didn't gear it right... find what speed you LIKE to be, be honest here, if you want 50, then make sure 3rd (32 or 28T min) gear hits 50, don't BS on this, otherwise you'll be eating chains very quickly.
G.
ebike11 said:
gman1971 said:
markz said:
Obviously you want high rpm's when climbing!
I was thinking of cruising on flats its alright to use 1/3 throttle right? To save battery capacity (Ah)
I find when I am in a small rear cog, the front-side of the rear wheel tends to deflect away from cassette side, which mis-aligns the rear cogs engaging the chain, which is the newest problem I am having on my 26" wheel Townie. However when I am in the bigger cogs say 1/2 up the stack, there is no problem. The deflection is very noticeable from a stand still.
Not getting nearly the same distance out of this cyclone then my 9C clone, because I think the throttle is always cranked. So gearing is next.
Throttle is always cranked on the Cyclone or on the 9C clone?
Yeah, if things bend that bad, or bad enough to derail chains then that means you're running way too much torque, thus wrong gearing. You need higher RPM at the cassette so you don't need to ever use the small cogs.
A Cyclone 3k running 1/3 throttle is super-inefficient if you want to achieve any range: Electric motors peak efficiency near their max RPM for any given voltage; so, anything below that RPM range you're simply spending your battery to heat things up. Pulsing 72 (instead of 36) volts for running the motor at 1/4th of its 72V rated RPM means that your efficiency is in the gutters; specially so on a square wave controller like the Cyclone one. Its far better to run the Cyclone on 24V/36V at full throttle than a 72V a 1/3 the throttle. But in the end, this all boils down to gearing.
G.
Yeah..im going to also play aroud with gearing.
@gman..if I use the 52T which is almost the biggest I can find chainring for the crankset..then what is the calculation for the rear cassette? Large chainring to smallest cog in the cassette = fastest top speed OR large chainring to large cogs on the rear cassette or would that cancel things out?
Thanks!! The only thing to watch out for is that chainring is made out of Aluminum and not Steel, so that might lead to premature chain wear, again, something to watch out for... but I still think you should get it.
