[HELP] Upgrading my 1500W Cruiser ebike to a 3000W

[NightCruiser]

Hey everyone, it's been a month since I purchased my first ebike. I've been riding it and what I realized is that I need more power. There's a lot of hills where I live and some time becomes tedious to climb at 20km/h. So, I was thinking in upgrading to 3000w power motor. I saw MXUS 3K hub motor, but I don't know if my bike frame can handle it. I'll be glad if anyone can help me.

Happy new year every1!

My bike link: http://www.cruisershop.eu/towar/246/fatbike-oozee-fatracer-dc-7sp-shimano.html

 

[amberwolf]

Before deciding on parts, you should first determine how much power you actually need for your specific conditions. If you go to http://ebikes.ca/tools/simulator.html you can set up your conditions and try systems until you find one that is capable of meeting the demands of them, and how much power will be needed to do it, at what voltage and battery current, and for how long, and how many Wh the system will need to do the work for the range you require.

Besides just the motor and controller, keep in mind that if the power required doubles, the range can be halved (or less, depending on the battery, assuming the battery could even supply the higher power at all without damage to it).

So once you know what you need, then you can buy a new battery, motor, and controller to do what you need. (it may be cheaper to buy or build an entire new bike, and almost certainly easier than upgrading an existing one (especially if frame modifications are required), plus it gives you a spare for when there are problems with the new one).

 

[lnanek]

99% of the time you only need to upgrade the battery, controller, and display.

The motor is junk a hunk of copper windings and magnets and can handle double the power easily. You can check if the motor is getting hot with your usage and only upgrade it with things like statorade and thicker wires, or replace it with a larger one if it is overheating.

 

[E-HP]

I've been riding it and what I realized is that I need more power. There's a lot of hills where I live and some time becomes tedious to climb at 20km/h. So, I was thinking in upgrading to 3000w power motor.

Power comes from the battery not the motor. Unless you order a motor with a specific winding that's more suited for your riding style and conditions, then simply upgrading to a 3kW motor is as likely to decrease performance as much as it is likely to increase it. If you're going to add all of that extra weight, add it in the form of more battery, so you can increase the available current. Then upgrade the controller to take advantage of the extra current. Then, if you get the performance you're looking for, it becomes a matter of heat management.

As an example, my 1500W motor is regularly subject to 7kW peaks and can climb any hill I've encountered, provided there is enough traction. A 3kW motor would feel like a boat anchor. And the torque and power curves between it and a MXUS 3kW, with the same motor winding, are almost identical:
https://ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_80_0.05_24&cont=cust_70_200_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&bopen=true&cont_b=cust_70_200_0.03_V&motor_b=MX3005_SA&batt_b=cust_80_0.05_24&wheel_b=25i&mass_b=110&hp_b=0

Adding Statorade helps with cooling. In the example above, the 3kW motor selected assumes Statorade, but without it, the MXUS 3kW would melt in 6.3 minutes at full throttle.
https://ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_80_0.05_24&cont=cust_70_200_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&bopen=true&cont_b=cust_70_200_0.03_V&motor_b=MX3005&batt_b=cust_80_0.05_24&wheel_b=25i&mass_b=110&hp_b=0

 

[NightCruiser]

Right now I have a 48v controller, and my battery is 20ah. I was thinking in upgrading the battery, but only after building a case or box for the bike frame. Thank you for your help everyone. Loving the ebike community.

So basically, I need to:
1st - Make a bigger battery, how much bigger?
2nd - Buy another controller, which do you suggest?
3nd - Buy statorade and hub sinks for cooling.

By doing this am I capable of going at what
top speed in flat terrain? I'm 80kg+25kg(bike weight) = 242 pounds total weight

Here's my bike

 

[amberwolf]

my battery is 20ah.

That is just the capacity of the battery, which does not directly indicate the power (watts) it could potentially handle.

You'd need to look at the specs for the battery from the manufacturer (of the battery, or the bike if it came with it) to see what it is designed to be capable of, and then it's generally safe to cut that by some percentage depending on the source, to be sure it's not being overstressed. (sellers too-often lie, by omission, intent, misinterpretation, or insufficient knowledge of how things work).

But again, before you worry about anything else, I still highly recommend first making yourself a list of exactly what you need the vehicle to do for you, under what conditions, at what maximum sustained speed under the worst of those conditions, and for what range at that maximum speed under the worst of those conditions.

Without knowing those, then anything you get may or may not be able to do what you want, or may be far in excess of what you need--either way would be money you could spend on something else that does need to be better.

 

[BalorNG]

If you have steep hills, and you have trouble riding up them, you don't actually need more POWER, you need more TORQUE capacity, because the motor like you have have pretty poor torque capacity - a 350w rated geared motor like 2x better than 1000w DD motor, basically (I've did tests myself). Of course due to internal gearing it has less top speed, but do you really need to move faster than 30 mph on fully rigid bike with terribly aero like you have?

A 1000w *geared* motor will be MUCH, much better at climbing and lighter, too - because it is going to MUCH more efficient when climbing, which is what you actually want.

 

[NightCruiser]

I requested a local ebike mechanic to make my bike. He said that it's kind of dangerous to do these kind of things. I'll be with him Ina few days and Ill ask the details about the battery.

Thank you for your help, so there's no need for new motor. I'm looking for 35mph top speed at any type of inclination.

 

[E-HP]

Right now I have a 48v controller, and my battery is 20ah. I was thinking in upgrading the battery, but only after building a case or box for the bike frame. Thank you for your help everyone. Loving the ebike community.

Can you share more details about your battery pack (current capability, type/brand of cells used)? For 48V, those whale shark packs can hold either 13S5P of 18650 size cells or 13S4P of 27100 size cells. There are no combos of 18650 cells than can provide 20Ah (with the highest capacity cells, 17.5Ah would fit), so it's likely 27100, which there are plenty that store 5Ah, which would be 20Ah. 27100 cells can provide anywhere from 7A or 45A per cell depending on the brand/type, so if you have really good cells, you may have enough battery power and you might benefit from just upgrading the controller.
If they are generic Chinese cells, then wait until you can buy more battery before doing any upgrades. If the battery description in the add doesn't say what cells are used, then 99% chance they are generic cells.

 

[amberwolf]

Thank you for your help, so there's no need for new motor. I'm looking for 35mph top speed at any type of inclination.

If you use the simulator youll see that power requirements goes up very quickly depending on slope, and that's dependent on the weight of the whole system, rider, bike, anything else you carry, and any headwinds.

To be able to do literally "any type of inclination", it could take many thousands of watts, meaning a different motor, controller, wiring, battery, and a different type of frame (longer) than what you have, so it won't flip over accelerating up the steeper hills.

If you mean something else, you'd need to make yourself a list of the actual specific conditions you must ride in, terrain it's on, road conditions, etc., and the weight of you and the system/bike/etc., the max speed you must go under the worst case conditions, the range you need in that event, etc. The more detail you give yourself, the better you can use the simulator to determine what it takes to do that job.

We don't have enough info to do any of this for you; you must make this detailed list yourself.

 

[E-HP]

If you have steep hills, and you have trouble riding up them, you don't actually need more POWER, you need more TORQUE capacity, because the motor like you have have pretty poor torque capacity - a 350w rated geared motor like 2x better than 1000w DD motor, basically (I've did tests myself). Of course due to internal gearing it has less top speed, but do you really need to move faster than 30 mph on fully rigid bike with terribly aero like you have?

A 1000w *geared* motor will be MUCH, much better at climbing and lighter, too - because it is going to MUCH more efficient when climbing, which is what you actually want.

Which geared hub would that be. I noticed that even a MAC 12T melts in a few minutes on only a 10% grade, and can't find any other geared hubs that can do better.
https://ebikes.ca/tools/simulator.html?motor=MMAC12T&batt=B4823_AC&cont=C20&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=10&wheel=26i&mass=110

*unless you're talking about oil cooling the geared hub

you don't actually need more POWER, you need more TORQUE capacity

You can't increase torque without increasing power, Power and Torque are outputs, not the variables. The variables that contribute to torque are voltage and current.

If you have 80V @ 70A or 70V @ 80A, the torque is the same (top speed changes but for the torque curves before drop off):
https://ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_80_0.05_24&cont=cust_70_200_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&bopen=true&cont_b=cust_80_230_0.03_V&motor_b=Leaf%205T&batt_b=cust_70_0.05_24&wheel_b=25i&mass_b=110&hp_b=0

To increase torque, you either need to increase current:
https://ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_80_0.05_24&cont=cust_70_200_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&bopen=true&cont_b=cust_80_230_0.03_V&motor_b=Leaf%205T&batt_b=cust_80_0.05_24&wheel_b=25i&mass_b=110&hp_b=0

or increase voltage:
https://ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_80_0.05_24&cont=cust_70_200_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&bopen=true&cont_b=cust_70_200_0.03_V&motor_b=Leaf%205T&batt_b=cust_90_0.05_24&wheel_b=25i&mass_b=110&hp_b=0

both of which increase power, and torque.

 

[BalorNG]

If you have steep hills, and you have trouble riding up them, you don't actually need more POWER, you need more TORQUE capacity, because the motor like you have have pretty poor torque capacity - a 350w rated geared motor like 2x better than 1000w DD motor, basically (I've did tests myself). Of course due to internal gearing it has less top speed, but do you really need to move faster than 30 mph on fully rigid bike with terribly aero like you have?

A 1000w *geared* motor will be MUCH, much better at climbing and lighter, too - because it is going to MUCH more efficient when climbing, which is what you actually want.

Which geared hub would that be. I noticed that even a MAC 12T melts in a few minutes on only a 10% grade, and can't find any other geared hubs that can do better.
https://ebikes.ca/tools/simulator.html?motor=MMAC12T&batt=B4823_AC&cont=C20&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=10&wheel=26i&mass=110

*unless you're talking about oil cooling the geared hub

you don't actually need more POWER, you need more TORQUE capacity

You can't increase torque without increasing power, Power and Torque are outputs, not the variables. The variables that contribute to torque are voltage and current.

If you have 80V @ 70A or 70V @ 80A, the torque is the same (top speed changes but for the torque curves before drop off):
https://ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_80_0.05_24&cont=cust_70_200_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&bopen=true&cont_b=cust_80_230_0.03_V&motor_b=Leaf%205T&batt_b=cust_70_0.05_24&wheel_b=25i&mass_b=110&hp_b=0

To increase torque, you either need to increase current:
https://ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_80_0.05_24&cont=cust_70_200_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&bopen=true&cont_b=cust_80_230_0.03_V&motor_b=Leaf%205T&batt_b=cust_80_0.05_24&wheel_b=25i&mass_b=110&hp_b=0

or increase voltage:
https://ebikes.ca/tools/simulator.html?motor=Leaf%205T&batt=cust_80_0.05_24&cont=cust_70_200_0.03_V&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=25i&mass=110&bopen=true&cont_b=cust_70_200_0.03_V&motor_b=Leaf%205T&batt_b=cust_90_0.05_24&wheel_b=25i&mass_b=110&hp_b=0

both of which increase power, and torque.

Torque is a variable in a way that a different motor will have VERY different torque output at same amperes, and what is much more important - very different waste heat output at same torque!

Well, now that OP clarified his position and wants to blast up ANY hill at 35 mph.
Unfortunately, that is no longer a e-bike but a fully fledged emoto and it would, indeed, require a different motor, a different battery and controller (50A battery continuous at the very least, and most definitely higher voltage as well, even 72 is barely enough) and most importantly - a different bike

35 mph up 10% hill would, indeed, consume about 3 kw of raw mechanical power before losses, which are going to be quite significant as well.

If OP wants further help, I recommend him opening a thread in e-motorcycling section.