new cyclone 3000 w mid-drive kit?

[gman1971]

Got it, thank you turbo1889 and everyone else.

Just to add to what turbo1889 said, running the pack over its rated C will also reduce considerably the # of times the pack can be recharged really fast. Plus you run the risk of cell puffing and that could lead to a fire. Seriously dude, I've set old lithium packs on fire just for the fun of it and they burn pretty darn good, more like a fiery flare plus the stink is out of this world toxic... I just wouldn't screw around with this kind of stuff.

G.

 

[gman1971]

turbo1889 nailed this on the head with his explanation a few posts above. I personally wanted my bike to do both: tow a heavy load up hill at 12-14 mph and cruise effortlessly at 32 mph on the roads.... this is the reason why I went with this setup.

G.

But why not a one speed snow bike with a cyclone.

Rephrasing:


What are the shortcomings of a [mid drive] Fatbike used for snow only? with one speed?

The bike would be rather slow like a tractor if it had only the lowest gear. And if it had only the highest gear it would stall on snow pack with breakable crust and hills. It would be more like the MXUS hub motor fatbike [ 1 speed] I have. You'll need a little run for the steeper hills and you may have to ride faster than you like to keep the thing running. It would not creep as good as it could with a lower gears. Steeper hill mid hill starts are not possible with a one speed or in the highest gear.

The MXUS fatbike excels on flatland snow but it is heavier and maybe not as efficient as a mid drive with gears [gears and chains have friction]? Thinking efficiency with snow bikes is simply dreaming..They can use over 150 Wh/mi while milling along in snow.

 

[Mikebike]

So now that I am looking for a new battery, I figured that I should also get some sort of a battery on/off switch/emergency disconnect switch or some sort of manually resettable circuit breaker to place in between the battery and the controller. I am having trouble locating a specific part for higher voltage/amperage DC.
Been searching these forums and internet and it is not clear to me what people are using-if they are using anything at all?
I am uncomfortable just using the spark arrestor type connectors as the connect/disconnect. In my opinion, this system should have a circuit breaker or a fuse and a switch before the controller?
If this is the wrong place to post this please let me know and I will change.

 

[StinkyGoalieGuy]

So now that I am looking for a new battery, I figured that I should also get some sort of a battery on/off switch/emergency disconnect switch or some sort of manually resettable circuit breaker to place in between the battery and the controller. I am having trouble locating a specific part for higher voltage/amperage DC.
Been searching these forums and internet and it is not clear to me what people are using-if they are using anything at all?
I am uncomfortable just using the spark arrestor type connectors as the connect/disconnect. In my opinion, this system should have a circuit breaker or a fuse and a switch before the controller?
If this is the wrong place to post this please let me know and I will change.

This is a great switch I have been using:
http://www.longacreracing.com/products.aspx?itemid=1643&prodid=7594&pagetitle=Push-Pull+Battery+Disconnect+Switch+-+2+Terminal

It claims to be good for 150amps continuous, at 48 volts.

Slam it with your palm to shut off. Twist it 1/8 turn and it pops back out into the "on" position. I have it mounted sideways (vertical vs. horizontal) on the side of the bike frame for easy panic stopping.

 

[gman1971]

So now that I am looking for a new battery, I figured that I should also get some sort of a battery on/off switch/emergency disconnect switch or some sort of manually resettable circuit breaker to place in between the battery and the controller. I am having trouble locating a specific part for higher voltage/amperage DC.
Been searching these forums and internet and it is not clear to me what people are using-if they are using anything at all?
I am uncomfortable just using the spark arrestor type connectors as the connect/disconnect. In my opinion, this system should have a circuit breaker or a fuse and a switch before the controller?
If this is the wrong place to post this please let me know and I will change.

Something like this?

http://www.omega.com/pptst/SSRL240_660.html

G.

 

[turbo1889]

Yes, it is possible to find circuit breakers that are capable of handling 36VDC but you have to be very careful about making sure it is actually rated for higher DC voltages

----- Many circuit breakers are only rated for AC not DC use (there is a huge difference in the engineering required because DC current arcs differently then AC does).
----- There are a ton of cheap 6-12VDC circuit breakers out there that work excellently for 12VDC but will fail miserably at 24-72VDC e-bike current levels.
----- For a little more money with a little less selection there are 24VDC (often actually rated at 32VDC) circuit breakers out there (intended for 18-wheeler and tractor applications) and they do work excellently for 24V e-bike systems and will sometimes work for 36V systems as well but its a gamble.
----- There are various "scooter" type circuit breakers out there with voltage ratings that vary from 24V to 48v systems and many of them are good and will work but you do sometimes run into some that aren't quite up to the task with cheapo workmanship with prices running from $5-$30 each or so.
----- There are some industrial and marine application 40-to-48VDC circuit breakers that are excellent but a little on the pricey side ($30-$100 a pop).
----- You can sometimes locate industrial and specific application DC circuit breakers with even higher DC voltage ratings.

You can find the "scooter" type circuit breakers by just doing an internet search for "scooter circuit breaker" and you will get all kinds of results with some bigger names on the internet with wider selections. Look closely at the pictures and read the ratings actually printed on the units in the pictures not just what they claim in their website and try to find something decent for a decent price.

Or if you want to spend a little money and get something you know is decent then go for an industrial/marine 40-to-48VDC rated circuit breaker preferably waterproof, manual-reset, large bolt and nut terminals. I'm personally partial to the "Cooper/Bussmann CB-185" series (42VDC rated perfect for a 24v or 36V e-bike system) which if you shop around for you can pick on up for less then $50 but you do pay a premium for that level of quality compared to just using one of the scooter type breakers.



Switches are actually a lot harder, its hard to find switches that are actually rated for e-bike DC voltage levels and high amp values. Often you end up having to use the best 24VDC rated switch you can find with a lot higher Amp rating then what your actually using and hope it holds up and doesn't arc over on the contacts with the higher level of DC voltage. That's why I like to find a circuit breaker with a manual button(s) on it preferably not only a reset button but also a disconnect or test button so that it can be used as a manual emergency off button. The CB-185 has a big red button that turns the circuit off manually so its not only a best quality circuit breaker actually rated for the application but also serves as an emergency shut-off switch as well.

 

[turbo1889]

. . .

This is a great switch I have been using:
http://www.longacreracing.com/products.aspx?itemid=1643&prodid=7594&pagetitle=Push-Pull+Battery+Disconnect+Switch+-+2+Terminal

It claims to be good for 150amps continuous, at 48 volts.

Slam it with your palm to shut off. Twist it 1/8 turn and it pops back out into the "on" position. I have it mounted sideways (vertical vs. horizontal) on the side of the bike frame for easy panic stopping.

Nice Find !!! (you posted while I was writing my post).

 

[Mikebike]

Stinky, you are the man. Ordered switch. Perfect.
G, I think the relay concept is beyond my understanding at this point but I thank you and really appreciate all your comments. The stuff you wrote about your gearing I am wrapping my head around and is very helpful.

 

[gman1971]

Stinky, you are the man. Ordered switch. Perfect.
G, I think the relay concept is beyond my understanding at this point but I thank you and really appreciate all your comments. The stuff you wrote about your gearing I am wrapping my head around and is very helpful.

The relay is solid state, so there will be no sparks when you power it up/down. I think those eBikes really need something like that (solid state) so you can just shut it off. The switch posted by Stinky seems like a great option! I guess I am the suicide rider not having one and sitting on a C3000 Crouch e-Rocket...

G.

 

[turbo1889]

Yah, I learned my lesson years ago when I had a road bike that I had put a DIY RC friction drive on. WAY FAST especially when tucked in nice and tight, I built my own throttle with a tiny squeeze button buried in the down drop bar tape.

One day, screaming down the road at 30-mph I saw a situation developing ahead and stopped squeezing the grip which should have turned the motor off.

It didn't turn off and with horror I realized the button was stuck ON !!!

Motor, controller, and batteries all behind me tucked under my rear seat with no way to access except some frantic useless grabs !!!

No master safety switch !!!

Full brakes only slowed me slightly (old style rim brakes) to like maybe 27-mph if that !!!



I bailed from the bike and it continued screaming down the road tipping over slowly as it went and right under the front of one of a left turning SUV who I could tell had no intention of yielding to anyone much less a cyclist (the situation I saw developing).

CRUNCH !!! Went the bike and I was ROAD RASH city in the gutter a little ways back.



NEVER AGAIN !!! Always have some way of shutting off the bike within easy reach even if its just having the main battery plugs within reach to grab and yank apart.

 

[gman1971]

WOW, that sounds like some scary oh-shit moment... bailing from the bike at 27 mph probably hurt and I know what I am talking about I've had something like that happen to me with the GNG but not at 27mph, more like 3 mph, and it was due to salt contamination on the connector so the bike wouldn't come to a complete stop at a red light b/c the throttle was stuck at ~5% and since the GNG didn't have a way to cut throttle with a switch like the Cyclone throttle does the Bike flipped and I fell to the ground... I was fine and the fall made the motor stop... but after that I realized how important was to waterproof your connectors...

G.

Yah, I learned my lesson years ago when I had a road bike that I had put a DIY RC friction drive on. WAY FAST especially when tucked in nice and tight, I built my own throttle with a tiny squeeze button buried in the down drop bar tape.

One day, screaming down the road at 30-mph I saw a situation developing ahead and stopped squeezing the grip which should have turned the motor off.

It didn't turn off and with horror I realized the button was stuck ON !!!

Motor, controller, and batteries all behind me tucked under my rear seat with no way to access except some frantic useless grabs !!!

No master safety switch !!!

Full brakes only slowed me slightly (old style rim brakes) to like maybe 27-mph if that !!!



I bailed from the bike and it continued screaming down the road tipping over slowly as it went and right under the front of one of a left turning SUV who I could tell had no intention of yielding to anyone much less a cyclist (the situation I saw developing).

CRUNCH !!! Went the bike and I was ROAD RASH city in the gutter a little ways back.



NEVER AGAIN !!! Always have some way of shutting off the bike within easy reach even if its just having the main battery plugs within reach to grab and yank apart.

 

[robocam]

I'd like to make some calculations using your figures. Do you know what your top speed is in your lowest gear? How many teeth are on your largest sprocket in your cassette? Are you using 26" wheels with regular (~2" wide) tires on them? Is it correct that your drivetrain chainring has 44T and your bike chain crankset chainring has 48T on it? Do you know how many teeth are on the motor sprocket of the Cyclone? Is it 13? I'm trying to get an idea of how my bike might behave with that mid drive.

And would anyone happen to know if a Cycle Analyst can plug into the Cyclone's controller to limit the current?

Also, why did your cadence go up when you swapped in the 48T? The 44T is what determines the cadence. If your motor speed didn't change, your cadence should not have changed.

With the supplied 44-44T crank mine was running at 115-120 cadence on 48V 12S LiPo, average top speed of around 32 mph.

...With the 44/48 motor overdrive the cadence has gone up to 130 when cruising in 8th gear, but not that I really care when I am going to work with 3 layers of coats and snowmobile boots...

G.

 

[gman1971]

Top speed is highly variable depending on conditions, but I would consider 32mph with no wind on flat my bike's top speed with ~46 volts left in the pack.

32mph is achieved with a 13T-44T gearing on motor to crank chain,and a 48T-15T (sometimes 17T) gearing on the crank to cassette chain. If I switch to the 13T my speed decreases vs 15T, and on the 11T the speed decreases even further and amp draw pegs at 40 amps.

The 48-15T is exactly the same as it was before when I ran the 13T-44T and 44T-13T, for the same top speed of 32 mph; except now I am running the 15T or 17T rear sprockets which should help with chain longevity; plus if I ever went higher than 48V it will allow for some ridiculous top speed.

The tires I run are 26x2.1 (with 240 spikes) on rear and 26x1.95 (with 120 spikes) on front. Both 26"

I have my CA hooked up to the Shunt resistor and you can also hook (solder) the throttle input to the CA for current limiting; I just haven't done it. Not sure if its worth it tho... but that's just a thought.

So to explain the 130 cadence statement I will start by saying that my bike with the wheels off the ground with the former 11-44T combo had a 52 mph top speed, cadence wasn't measured then but we can figure that out based on top speed; but when riding on the street the top speed goes down to just 30-32 mph, which means the motor is running roughly at half speed of its max RPM, which most likely it means I am not in the sweet efficient spot the motor should probably be. This is very easy to see when you are pedaling your bike (no motor), try spinning @ 120 RPM cadence with an 11t-44T combo, unless you have seriously strong legs (torque) you'll be hard pressed to achieve that, and that is because you don't have the power to spin it (you can't deliver the necessary amount of torque at the given RPM figure) so now switch to a 20T and 44T, all of the sudden spinning at 120 becomes a much easier proposition (half the torque required) but now you pedal twice as fast, and start taxing your aerobic pathway (your heart) and challenging your muscular coordination to spin the crank that much faster, all due to the low effort high repetition on your legs; so if you're not in Tour de France shape you'll run out of steam rather fast... but an electric motor, in the other hand, like the C3000 motor which has a lot of RPM left on the tank, using the same trick that works for humans also seems to work well in this case when the C3000 motor is clearly running at roughly half of its unloaded max RPM.

Doing what I did shifted the RPM to torque conversion from the crank/chain to the rear cassette; a 17T has more leverage over the wheel than an 11T, thus it requires less force coming from the chain, so because it requires less force to move, the motor now has to spin faster to achieve the same speed and faster RPM seems to be a more efficient motor.

48-15T is a 3.2 ratio.
44-13T is a ~3.4 ratio; roughly a 6% gear ratio change, which is around what the difference is from former cadence. So that means I could probably still get a 48T drive crank and a 54T pedal crank (48T-54T-32T crank) and increase efficiency probably even further by allowing the motor side to spin faster.

I installed this 44-48 crank this weekend and during today's commute (first commute since install) I noticed a 2 Ah drop (from 18,xxx mAh to 16,xxx) in energy use over the same exact 8 miles, and I also did notice that motor tends to bog down less when going up hill.. so take this for what is worth. Also worth noticing is that 30mph cruising speed was achieved with 14xx Watts vs 16xx watts, so there is probably more efficiency to be gained.

Again the original reason why I did this wasn't to go faster or anything like that, I did it to reduce the amount of force transferred through the chain, and if I was put a 48T (for a 48-48-32T) then I'll have once again the same 1:1 ratio at the crank, and I'll be forced to run the 13T-11T sprockets for cruising at 30mph again and have the same amount of torque going through the bike chain.

G.

I'd like to make some calculations using your figures. Do you know what your top speed is in your lowest gear? How many teeth are on your largest sprocket in your cassette? Are you using 26" wheels with regular (~2" wide) tires on them? Is it correct that your drivetrain chainring has 44T and your bike chain crankset chainring has 48T on it? Do you know how many teeth are on the motor sprocket of the Cyclone? Is it 13? I'm trying to get an idea of how my bike might behave with that mid drive.

And would anyone happen to know if a Cycle Analyst can plug into the Cyclone's controller to limit the current?

Also, why did your cadence go up when you swapped in the 48T? The 44T is what determines the cadence. If your motor speed didn't change, your cadence should not have changed.

With the supplied 44-44T crank mine was running at 115-120 cadence on 48V 12S LiPo, average top speed of around 32 mph.

...With the 44/48 motor overdrive the cadence has gone up to 130 when cruising in 8th gear, but not that I really care when I am going to work with 3 layers of coats and snowmobile boots...

G.

 

[cwah]

30mph on flat ground no wind can be achieved by the bbs02. If cyclone can do 40mph you better stick with bbs lol

 

[robocam]

I think of the difference as like having a car with a little 4-cylinder engine vs. a big block V8. Sure, both can reach similar speeds, but one can do it a lot more quickly and effortlessly. The Cyclone also allows the user to choose what secondary reduction it uses. It's fixed in the BBS. As a tinkerer, I cannot accept that =)

30mph on flat ground no wind can be achieved by the bbs02. If cyclone can do 40mph you better stick with bbs lol

 

[robocam]

Thanks so much! I was actually interested in your top speed in 1st gear (slowest gear, so that's why I wanted to know how many teeth are in the largest gear in your cassette), not your maximum top speed. I chose 1st gear so that you wouldn't have to go so fast, and drag would not be a significant factor.

So your energy consumption dropped by 200 watts (or 2Ah over 8 miles) when you decreased your gear ratio!? That is very interesting. It goes against my assumption that motors operate the most efficiently at the highest RPM. I'm going to have to run some experiments =) Maybe someone with a stronger electrical background can explain this.

I use my bike at low speeds primarily, so that's why I'm interested in increasing the gear ratio. I figured that if I'm crawling around, I can try to gain more battery life by letting the motor spin faster, but if what you're saying is true, I may not need to do this.

Top speed is highly variable depending on conditions, but I would consider 32mph with no wind on flat my bike's top speed with ~46 volts left in the pack.

32mph is achieved with a 13T-44T gearing on motor to crank chain,and a 48T-15T (sometimes 17T) gearing on the crank to cassette chain. If I switch to the 13T my speed decreases vs 15T, and on the 11T the speed decreases even further and amp draw pegs at 40 amps.

The 48-15T is exactly the same as it was before when I ran the 13T-44T and 44T-13T, for the same top speed of 32 mph; except now I am running the 15T or 17T rear sprockets which should help with chain longevity; plus if I ever went higher than 48V it will allow for some ridiculous top speed.

The tires I run are 26x2.1 (with 240 spikes) on rear and 26x1.95 (with 120 spikes) on front. Both 26"

I have my CA hooked up to the Shunt resistor and you can also hook (solder) the throttle input to the CA for current limiting; I just haven't done it. Not sure if its worth it tho... but that's just a thought.

So to explain the 130 cadence statement I will start by saying that my bike with the wheels off the ground with the former 11-44T combo had a 52 mph top speed, cadence wasn't measured then but we can figure that out based on top speed; but when riding on the street the top speed goes down to just 30-32 mph, which means the motor is running roughly at half speed of its max RPM, which most likely it means I am not in the sweet efficient spot the motor should probably be. This is very easy to see when you are pedaling your bike (no motor), try spinning @ 120 RPM cadence with an 11t-44T combo, unless you have seriously strong legs (torque) you'll be hard pressed to achieve that, and that is because you don't have the power to spin it (you can't deliver the necessary amount of torque at the given RPM figure) so now switch to a 20T and 44T, all of the sudden spinning at 120 becomes a much easier proposition (half the torque required) but now you pedal twice as fast, and start taxing your aerobic pathway (your heart) and challenging your muscular coordination to spin the crank that much faster, all due to the low effort high repetition on your legs; so if you're not in Tour de France shape you'll run out of steam rather fast... but an electric motor, in the other hand, like the C3000 motor which has a lot of RPM left on the tank, using the same trick that works for humans also seems to work well in this case when the C3000 motor is clearly running at roughly half of its unloaded max RPM.

Doing what I did shifted the RPM to torque conversion from the crank/chain to the rear cassette; a 17T has more leverage over the wheel than an 11T, thus it requires less force coming from the chain, so because it requires less force to move, the motor now has to spin faster to achieve the same speed and faster RPM seems to be a more efficient motor.

48-15T is a 3.2 ratio.
44-13T is a ~3.4 ratio; roughly a 6% gear ratio change, which is around what the difference is from former cadence. So that means I could probably still get a 48T drive crank and a 54T pedal crank (48T-54T-32T crank) and increase efficiency probably even further by allowing the motor side to spin faster.

I installed this 44-48 crank this weekend and during today's commute (first commute since install) I noticed a 2 Ah drop (from 18,xxx mAh to 16,xxx) in energy use over the same exact 8 miles, and I also did notice that motor tends to bog down less when going up hill.. so take this for what is worth. Also worth noticing is that 30mph cruising speed was achieved with 14xx Watts vs 16xx watts, so there is probably more efficiency to be gained.

Again the original reason why I did this wasn't to go faster or anything like that, I did it to reduce the amount of force transferred through the chain, and if I was put a 48T (for a 48-48-32T) then I'll have once again the same 1:1 ratio at the crank, and I'll be forced to run the 13T-11T sprockets for cruising at 30mph again and have the same amount of torque going through the bike chain.

G.

I'd like to make some calculations using your figures. Do you know what your top speed is in your lowest gear? How many teeth are on your largest sprocket in your cassette? Are you using 26" wheels with regular (~2" wide) tires on them? Is it correct that your drivetrain chainring has 44T and your bike chain crankset chainring has 48T on it? Do you know how many teeth are on the motor sprocket of the Cyclone? Is it 13? I'm trying to get an idea of how my bike might behave with that mid drive.

And would anyone happen to know if a Cycle Analyst can plug into the Cyclone's controller to limit the current?

Also, why did your cadence go up when you swapped in the 48T? The 44T is what determines the cadence. If your motor speed didn't change, your cadence should not have changed.

With the supplied 44-44T crank mine was running at 115-120 cadence on 48V 12S LiPo, average top speed of around 32 mph.

...With the 44/48 motor overdrive the cadence has gone up to 130 when cruising in 8th gear, but not that I really care when I am going to work with 3 layers of coats and snowmobile boots...

G.

 

[gman1971]

30mph on flat ground no wind can be achieved by the bbs02. If cyclone can do 40mph you better stick with bbs lol

Comparing bikes top speed is absolutely pointless; we don't know the drag on your bike; but I can tell you this tho, if CA is correct and I am pushing very close to 40 amps, I doubt your BBS will last very long pushing 1500+ watts for 20+ minutes. I run mine with spiked wide tires and I wear triple layers of pants, clothes and a full face helmet that add a lot of drag and weight; now we'll see how fast my bike runs when I am wearing nothing but a t-shirt and cycling pants with clipless bike shoes and running road skinny tires this spring... I suspect my bike will be pushing 40 mph.

Also, using the BBSxx how do you plan on having a double chainring? I stated very clearly why I chose the Cyclone over the Bafang, so when someone solves that problem I'll consider the BBSxx, in the meantime I'll stick with my "half the price, twice the power Cyclone" which BTW, I am only running at 48V (more like 44.4V since its 12S LiPo) and I doubt the BBS02 can match the performance of the Cyclone on 12S b/c the GNG I had before was already pushing it at 30mph with 22 amps peak on the controller, more like a 25mph cruise. That extra 5mph (from 25-30mph) requires a lot of power that my GNG 22 amp controller simply couldn't deliver.

G.

 

[gman1971]

No problem, I just read this and I'll get you that number this afternoon. I'll run the bike with the 32T chainring and the 36T Sprocket at max throttle and note the top speed.

Yes, but 2 Ah could've due to many factors too, and since its only one day "data sample" I wouldn't call it a victory yet, once I've run the bike over a couple of weeks I'll have a much better understanding of how the changes really affected the overall performance. Now, what I can tell you is that I've rarely hit the amp limit on the controller in this last two days whereas before I would hit the 40 amp limit pretty much right off the bat. Today for example was a really bad day to brag about eBike endurance: strong 20mph headwind with probably double the speed bursts, my peak draw was only 36.2 amps, average speed was 24.3 mph, -10 C on the bike "exterior" temp sensor. Total distance 8.240 miles, and 9.984 Ah used. Around ~55.0 Wh/mile according to CA.... which is not bad, considering the insane headwind and very little pedaling I did. My routes to and from work are not the same either so I can't compare the data I get from my return trips; plus wind direction tends to change rather quickly around here, so one day you might encounter a 20mph headwind like today, and require almost 10Ah to get to work, other days a 20mph tailwind will get you to work with only 6 Ah and a 29 mph average speed.

G.

Thanks so much! I was actually interested in your top speed in 1st gear (slowest gear, so that's why I wanted to know how many teeth are in the largest gear in your cassette), not your maximum top speed. I chose 1st gear so that you wouldn't have to go so fast, and drag would not be a significant factor.

So your energy consumption dropped by 200 watts (or 2Ah over 8 miles) when you decreased your gear ratio!? That is very interesting. It goes against my assumption that motors operate the most efficiently at the highest RPM. I'm going to have to run some experiments =) Maybe someone with a stronger electrical background can explain this.

I use my bike at low speeds primarily, so that's why I'm interested in increasing the gear ratio. I figured that if I'm crawling around, I can try to gain more battery life by letting the motor spin faster, but if what you're saying is true, I may not need to do this.

 

[robocam]

When you noticed the reduction in power usage, was that when you were using the 48T and not the 32T? And now that you have the option to use the 32T, have you used it much on your commute?

No problem, I just read this and I'll get you that number this afternoon. I'll run the bike with the 32T chainring and the 36T Sprocket at max throttle and note the top speed.

Yes, but 2 Ah could've due to many factors too, and since its only one day "data sample" I wouldn't call it a victory yet, once I've run the bike over a couple of weeks I'll have a much better understanding of how the changes really affected the overall performance. Now, what I can tell you is that I've rarely hit the amp limit on the controller in this last two days whereas before I would hit the 40 amp limit pretty much right off the bat. Today for example was a really bad day to brag about eBike endurance: strong 20mph headwind with probably double the speed bursts, my peak draw was only 36.2 amps, average speed was 24.3 mph, -10 C on the bike "exterior" temp sensor. Total distance 8.240 miles, and 9.984 Ah used. Around ~55.0 Wh/mile according to CA.... which is not bad, considering the insane headwind and very little pedaling I did. My routes to and from work are not the same either so I can't compare the data I get from my return trips; plus wind direction tends to change rather quickly around here, so one day you might encounter a 20mph headwind like today, and require almost 10Ah to get to work, other days a 20mph tailwind will get you to work with only 6 Ah and a 29 mph average speed.

G.

Thanks so much! I was actually interested in your top speed in 1st gear (slowest gear, so that's why I wanted to know how many teeth are in the largest gear in your cassette), not your maximum top speed. I chose 1st gear so that you wouldn't have to go so fast, and drag would not be a significant factor.

So your energy consumption dropped by 200 watts (or 2Ah over 8 miles) when you decreased your gear ratio!? That is very interesting. It goes against my assumption that motors operate the most efficiently at the highest RPM. I'm going to have to run some experiments =) Maybe someone with a stronger electrical background can explain this.

I use my bike at low speeds primarily, so that's why I'm interested in increasing the gear ratio. I figured that if I'm crawling around, I can try to gain more battery life by letting the motor spin faster, but if what you're saying is true, I may not need to do this.

 

[gman1971]

The changes were noticed when going from a 44T to 48T, and I commute on the big chainring (48T) always, mostly due to chain alignment as the 6th 7th and 8th gears are where the chain is mostly aligned with the chainring to minimize crosschaining (another reason why I wanted to get out of the 11T and 13T sprockets for cruising). I only switch to the 32T chainring when I am going off road or towing stuff; or basically anytime I need to go into the first three gears on the cassette (28T, 32 or 36T sprockets)

When you noticed the reduction in power usage, was that when you were using the 48T and not the 32T? And now that you have the option to use the 32T, have you used it much on your commute?

No problem, I just read this and I'll get you that number this afternoon. I'll run the bike with the 32T chainring and the 36T Sprocket at max throttle and note the top speed.

Yes, but 2 Ah could've due to many factors too, and since its only one day "data sample" I wouldn't call it a victory yet, once I've run the bike over a couple of weeks I'll have a much better understanding of how the changes really affected the overall performance. Now, what I can tell you is that I've rarely hit the amp limit on the controller in this last two days whereas before I would hit the 40 amp limit pretty much right off the bat. Today for example was a really bad day to brag about eBike endurance: strong 20mph headwind with probably double the speed bursts, my peak draw was only 36.2 amps, average speed was 24.3 mph, -10 C on the bike "exterior" temp sensor. Total distance 8.240 miles, and 9.984 Ah used. Around ~55.0 Wh/mile according to CA.... which is not bad, considering the insane headwind and very little pedaling I did. My routes to and from work are not the same either so I can't compare the data I get from my return trips; plus wind direction tends to change rather quickly around here, so one day you might encounter a 20mph headwind like today, and require almost 10Ah to get to work, other days a 20mph tailwind will get you to work with only 6 Ah and a 29 mph average speed.

G.

Thanks so much! I was actually interested in your top speed in 1st gear (slowest gear, so that's why I wanted to know how many teeth are in the largest gear in your cassette), not your maximum top speed. I chose 1st gear so that you wouldn't have to go so fast, and drag would not be a significant factor.

So your energy consumption dropped by 200 watts (or 2Ah over 8 miles) when you decreased your gear ratio!? That is very interesting. It goes against my assumption that motors operate the most efficiently at the highest RPM. I'm going to have to run some experiments =) Maybe someone with a stronger electrical background can explain this.

I use my bike at low speeds primarily, so that's why I'm interested in increasing the gear ratio. I figured that if I'm crawling around, I can try to gain more battery life by letting the motor spin faster, but if what you're saying is true, I may not need to do this.

 

[robocam]

Interesting. I would think that you'd naturally use different gears with a new setup, negating any changes in average efficiency, assuming you run the motor at full throttle the majority of the time. For example, if you used a certain gear in the past for cruising, going to the 48T chainring would cause you to go faster. If you didn't want to go faster, you'd either not use full throttle, or you'd use a lower gear. Are you using less throttle with the 48T vs the 44T?

The changes were noticed when going from a 44T to 48T, and I commute on the big chainring (48T) always, mostly due to chain alignment as the 6th 7th and 8th gears are where the chain is mostly aligned with the chainring to minimize crosschaining (another reason why I wanted to get out of the 11T and 13T sprockets for cruising). I only switch to the 32T chainring when I am going off road or towing stuff; or basically anytime I need to go into the first three gears on the cassette (28T, 32 or 36T sprockets)

 

[gman1971]

And I do, I don't use the 13T sprocket anymore since I can now cruise at 30mph in the 15T or 17T sprockets depending on conditions/battery. If I run the 13T my speed actually decreases (motor doesn't have enough torque to pull the gear at the given RPM, or in simple terms it needs more power to go faster, so my bike is aerodynamically drag limited, not gear limited like it was when I first put it together with the 36T GNG crank, so now I have two gears left before I top out on 8th, and those extra gears I use when going downhill to reach 43mph.

But truth is I don't go any faster than before, because adding a bigger chainring/gear doesn't magically make it go faster... power is what determines the absolute fast that you can go. Again, power is the capacity to deliver force/torque at any given speed/RPM or better yet, power is the ability to do work over time; and gearing all it does is trades RPM for torque or torque for RPM... you chose, otherwise you'd have invented the perpetual motion machine... So when I am running my 36T sprocket with 32T chainring my speed is gear limited; as in, the motor can't deliver power b/c its out of the powerband when it maxes its RPM. So, when you add gears (or put a bigger chainring like you said) you are basically shifting the powerband back down (or up) and the motor can now keep on pushing, so when you hit redline on the next gear, you are out of the powerband yet again, so you shift and the powerband shifts down to match, and so on... well, thats until the power required to go forward exceeds the power the motor can supply and then you're aerodynamically drag limited, which is where I am now; and I would think that is a desirable thing on something like an eBike, so the motor is always cruising at the highest RPM that will deliver enough torque to go cruise, and in case of downhills you can still use these extra gears to go a little faster and it saves some stress from the 11T and 13T sprockets too.

G.

Interesting. I would think that you'd naturally use different gears with a new setup, negating any changes in average efficiency, assuming you run the motor at full throttle the majority of the time. For example, if you used a certain gear in the past for cruising, going to the 48T chainring would cause you to go faster. If you didn't want to go faster, you'd either not use full throttle, or you'd use a lower gear. Are you using less throttle with the 48T vs the 44T?

The changes were noticed when going from a 44T to 48T, and I commute on the big chainring (48T) always, mostly due to chain alignment as the 6th 7th and 8th gears are where the chain is mostly aligned with the chainring to minimize crosschaining (another reason why I wanted to get out of the 11T and 13T sprockets for cruising). I only switch to the 32T chainring when I am going off road or towing stuff; or basically anytime I need to go into the first three gears on the cassette (28T, 32 or 36T sprockets)

 

[gman1971]

Max speed with 36T pinion and 32T chainring is 11.4 mph.

G.

 

[robocam]

Thanks! So here is what I have so far.

Assuming the outer diameter of your wheel is 26", it will rotate 776 times per mile. At 11.4 mph, your rear wheel is rotating at 147.44 rpm. 36T(rear cassette)/34T(bike crank chainring) = 1.125, so 147.44 rpm x 1.125 brings us to 165.87 rpm (cadence) at the crankset. 44T(drivetrain crank)/13T(motor) = 3.38462, so 166 x 3.38462 = 561.47 rpm at the motor. The 4.9 reduction in the motor means the motor is spinning at 2751 rpm.

So at 44.4V, the cadence with a 44T drivetrain chainring is 166 rpm.
For comparison, at 48V, the pre-2016 belt-driven GNG mid drive spins the jackshaft at 570 rpm, resulting in a cadence of 570 / (44/12) = 155 rpm. The 2016 premium GNG would have a cadence of 105 rpm. The pre-2016 GNG data is from this thread. https://endless-sphere.com/forums/viewtopic.php?t=42785

Assuming a linear increase in speed as voltage increases, the Cyclone should give a cadence of 166 x (48.1/44.4) = 180 rpm, and 166 x (51.8/44.4) = 194 rpm with a 52V battery, all with a 44T drivetrain chainring. Moving to a 48T chainring would drop those values to 92% of what's shown, so if I had a 52V battery and a 48T drivetrain chainring, my cadence would max out at 178 rpm. Haha, I don't think I'll be pedaling with the motor.

And I completely understand that changing the ratios wouldn't make your bike faster if it was drag limited. I didn't know you were using full throttle.

I think I've figured out why you're using less power. You are actually allowing your motor to spin faster with your new gear combinations. Your 17/48 is a 0.35 and your 15/48 is a 0.31. Both are higher reductions than 15/44=0.34 and 13/44=0.30. The 0.35 is higher than the 0.34. The 0.31 is higher than the 0.30. That is why you're using less power. You're allowing your motor to spin faster, confirming what I suspected all along. Before you went to your "overdrive" setup, your motor was not operating at its "sweet spot." Now it is closer.

Max speed with 36T pinion and 32T chainring is 11.4 mph.

G.

 

[gman1971]

No problem man, glad it was of help.

I don't have the Cateye Strada Wireless cadence sensor on the eBike anymore, but yeah, pedaling on the 36-32T combo at full throttle is basically impossible; the thing spins so ridiculously fast that is just not possible to keep up with it; but then again, that's why it has as nice throttle so you can tone it down and pedal along with it if you really want. When you're pumping that much wattage pedaling becomes moot point, really; I suggest perhaps getting a PAS sensor and using that? The motor will handle pretty much anything you throw at it.

That's why I think that perhaps the ratio between the drivechain and the bikechain could be lowered even further, so instead of a .92 go to a .75 or something like that, that will provide even further "overdrive" and allow the motor to spin like crazy on the 20T or 22T pinion thus lowering the chain stress even further... I wonder where the point of max efficiency really lies at on this motor.

I imagine that a 10 volt increase will yield some serious power increase too, right now when the pack is at 43 volts I am only peaking at ~1600 watts which is little under 40 amps, still plenty capable of doing 30mph but when pack is fresh the thing peaks at ~2100 watts and pulls like a raped ape...

I am almost at the 100 cycles mark on the 2 Multistar 6S 12000 mAh packs I am using (almost 1000 miles) and I am beginning to notice a much sharper dropoff in initial voltage. Back when new these would hold 48V for quite a while but now they drop to 45V within 3 or 4 miles after leaving home. So perhaps the LiPos are starting to show their age... or perhaps is the single digit temperatures that gets to the packs even if they are wrapped in styrofoam... just hard to tell;

Thanks! So here is what I have so far.

Assuming the outer diameter of your wheel is 26", it will rotate 776 times per mile. At 11.4 mph, your rear wheel is rotating at 147.44 rpm. 36T(rear cassette)/34T(bike crank chainring) = 1.125, so 147.44 rpm x 1.125 brings us to 165.87 rpm (cadence) at the crankset. 44T(drivetrain crank)/13T(motor) = 3.38462, so 166 x 3.38462 = 561.47 rpm at the motor. The 4.9 reduction in the motor means the motor is spinning at 2751 rpm.

So at 44.4V, the cadence with a 44T drivetrain chainring is 166 rpm.
For comparison, at 48V, the pre-2016 belt-driven GNG mid drive spins the jackshaft at 570 rpm, resulting in a cadence of 570 / (44/12) = 155 rpm. The 2016 premium GNG would have a cadence of 98 rpm. The pre-2016 GNG data is from this thread. https://endless-sphere.com/forums/viewtopic.php?t=42785

Assuming a linear increase in speed, the Cyclone should give a cadence of 166 x (48.1/44.4) = 180 rpm, and 166 x (51.8/44.4) = 194 rpm with a 52V battery, all with a 44T drivetrain chainring. Moving to a 48T chainring would drop those values to 92% of what's shown, so if I had a 52V battery and a 48T drivetrain chainring, my cadence would max out at 178 rpm. Haha, I don't think I'll be pedaling with the motor.

And I completely understand that changing the ratios wouldn't make your bike faster if it was drag limited. I didn't know you were using full throttle.

I think I've figured out why you're using less power. You are actually allowing your motor to spin faster with your new gear combinations. Your 17/48 is a 0.35 and your 15/48 is a 0.31. Both are higher reductions than 15/44=0.34 and 13/44=0.30. The 0.35 is higher than the 0.34. The 0.31 is higher than the 0.30. That is why you're using less power. You're allowing your motor to spin faster, confirming what I suspected all along. Before you went to your "overdrive" setup, your motor was not operating at its "sweet spot." Now it is closer.

Max speed with 36T pinion and 32T chainring is 11.4 mph.

G.