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2kW Mid Drive Vs 3kW Direct Drive Hub Motor for 100cc Motorcycle?

Naruto007

10 µW
Joined
Dec 29, 2023
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5
Location
Karachi
Hi, I am from Pakistan. Which motor should I use for converting a 125cc Honda Bike. Typical use case is commuting on it to office daily with a pillion passenger. Motorcycle should be able to easily climb bridges.
3kW Hub motor or 2kW mid drive motor. I will use, 60V 72Ah LFP battery.
 
Hi, I am from Pakistan. Which motor should I use for converting a 100cc Honda Bike. Typical use case is commuting on it to office daily with a pillion passenger. Torque is more important than speed, bike should be able to easily climb bridges while stuck in traffic.

Which is better: 3kW Hub motor or 2kW mid drive motor.
I will use, 60V 72Ah LFP battery.
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Thanks.
 
I'd recommend going to the simulators at ebikes.ca (or other online simulators/calculators) and using them to determine the power, current, voltage, and battery capacity needed to overcome the conditions you have to ride in, at the speeds you ride at, with the total weight you have (bike/riders/etc), for the distance you want to go, etc.

Otherwise, best advice is to read the other threads on motorcycle conversions here that have been completed and are used in the same or worse conditions as you have, at the same or higher speeds, for the same or higher distances, etc., and copy what they did.
 
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Depends on your preferences, usage, conditions, budget, DIY skills (or budget to pay for creating all the necessary mounting parts), etc.

There's many posts around here that discuss the advantages and disadvantages of middrives vs hubs; many are for bicycle stuff but some are motorcycle; and often it doesn't matter--they apply either way. Some of the other build threads also discuss that.

As for applicability of mid or hub to your usage and conditions, there's not enough data for us to tell you. To even guess, you'd have to provide links to the specific equipment you'd be using, including all the gearing/drivetrain between the motor and wheel for middrive, and your actual specific riding conditions, terrain, slopes / lengths of bridges or other things that have to be climbed and what speed you need to do that at, and what total system/bike/rider/passenger/cargo weight to be carried, etc.

Then we'd have to go to the simulators and do all the work for you of figuring out what it would take to do all that. It's possible that someone might be willing to if all the required data from you was available to them, but if you have all that info you can do it too. ;)

If you don't already know what specific equipment/etc you'd be using, or what gearing, you really should take your info to the simulators and get guesstimates of what equipment you'll need.
 
It be a hubmotor for a flatland commuter.
On my planned 125cc Grom conversion I'll be using a 6k hubmotor. Some short steep hills, and some short 100kph runs. On my ebike it's upto 1500 watts to go about 50kph. So I just ballparked my power need. 4 times the power of my ebike should make a decent motorbike🤔.
 
It be a hubmotor for a flatland commuter.
On my planned 125cc Grom conversion I'll be using a 6k hubmotor. Some short steep hills, and some short 100kph runs. On my ebike it's upto 1500 watts to go about 50kph. So I just ballparked my power need. 4 times the power of my ebike should make a decent motorbike🤔.
Ya, I am also thinking of going with hub motor. But my main concern is torque. Can the bike climb a hill or bridge with at least the same speed as it did previously with two pillion passengers, without over heating.

Seller of the kit has shared these specs but provided no datasheet:
3000W average
Peak 4000W
(Torque 170Nm
Rpm 1100)

controller which comes with the kit is a generic 80A.
 

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What was the horsepower of the original motor?

To me, no data sheet, no buy..
 
Which is better: 3kW Hub motor or 2kW mid drive motor.
I don't see any pedals on that photograph, so I don't see using a standard mid-drive motor.

So, you are asking about a motor mounted where the petrol motor is and driving the rear wheel with a chain, or replacing the rear wheel with a motor.

Driving by chain means gear reduction is possible so a motor may spin faster and/or deliver greater torque. You might also switch to a Gates Carbon Belt drive.

Direct drive means no chain at all, and more room for a battery lower in the frame.

The weight of a hub motor will have significant effects on the response of the rear suspension if it's much different than the current hub assembly. It won't have much effect on the passenger weight - just the rear suspension response.

After this, you are into questions about desired RPM from the rear wheel (required - this is critical, what do you calculate?). Total expected weight. Desired range. Length of any significant hill you may need to climb.

You may not get complete information from any motor seller, but that won't stop you from calculating what you need, because you need what you need, based on what you want to attain. Ask for help about specifics.

Engineering means answering all of the questions, and then finding the sweet spot where they all overlap. Let us know.
 
This is a 4 speed with clutch and will bolt right into your frame. It basically a pit bike engine with an electric motor instead of a crankshaft. Your battery will be perfect. I am surprised these aren't discussed more here, they are used in many dirt bikes and can be pushed to 12KW. The gearbox may not be needed most of the time but is perfect for climbing hills and passengers because you can shift gears

 
This is a 4 speed with clutch and will bolt right into your frame. It basically a pit bike engine with an electric motor instead of a crankshaft. Your battery will be perfect. I am surprised these aren't discussed more here, they are used in many dirt bikes and can be pushed to 12KW. The gearbox may not be needed most of the time but is perfect for climbing hills and passengers because you can shift gears

Can you post some pics of your build?
 
Not building yet but plan to use one of those motors in a small honda TRX90 4 wheel ATV.
 
Not building yet but plan to use one of those motors in a small honda TRX90 4 wheel ATV.
Interesting. So you’re promoting kits on several threads that you have no direct experience with? Might be better to be up front and start off with, “I have no experience with these kits, but…” so you don’t leave the wrong impression.
 
I wouldn't say I'm promoting them or even implied I have used them,.. that's just your impression. I have posted a dozen times in many places asking for feedback on them and wondering why they get no consideration. There are plenty of dirt bikes sold with these motors and many push them to 12K or more. I have never seen bad feedback have you? The package with controller, charger, throttle and motor/gearbox is cheaper than most other options. The need for gears is debatable but is absolutely a benefit when you need a wide range of loads or speed. ATV's are often used for towing or climbing, I have one on order and will post my results. The forum poster expressed a need for something that can handle a passenger or hills some of the time. That is a perfect use for multiple gears. The big attraction is that they share mounting points with any vehicle made for pit bike style motors. That includes ATV's, pit bikes Groms and the bike this thread is all about. Just bolt it in, strap on a battery and go with no fabrication. I thought the original poster might be interested to know this is available. Why would that offend anyone?
 
Oh so I'm a bad guy.... unless its actually a good advice for someone looking for a bolt in solution. Then you would be the bad guy for not letting them know its even an option. I'll know when the slow boat from China gets here with mine. Why don't you let other people try things for themselves. Or,.. should we hide things from them until you've decided its good.
 
Oh so I'm a bad guy.... unless its actually a good advice for someone looking for a bolt in solution. Then you would be the bad guy for not letting them know its even an option. I'll know when the slow boat from China gets here with mine. Why don't you let other people try things for themselves. Or,.. should we hide things from them until you've decided its good.
You’re being deceptive. Start a thread to inform people rather than trying to convince people to “try this instead” of something else, which is the definition of promoting.

“Check out these instead.

Electric Motorcycle Hub Motor Kit High Speed Electric Motor For Motorcycle For Walton Motors Atlas Honda Bikes - Buy Electric Motor,Motor For Motorcycle,Electric Motor For Motorcycle Product on Alibaba.com


“Why not use one of these instead? They bolt right into your Grom mounts and have a 4 speed with clutch...”
 
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All comments I made are reasonable, I presented another choice,.... "just check it out".. was my only intent. Read my posts again with that knowledge.

Its how I respond to a poster who may not know of something else that's available. You guys can read into it whatever you want. Im sure you see a lot of blatant promotion but this wasn't it.. I could say you're promoting hub motors by suppressing alternatives. These people are looking for ideas and options. It may, be old news to you but I know it helped someone too. Give people a little credit to digest information for themselves. I'll end my conversation here because this is way overblown. I get good info from these forums and try to contribute
 
I don't really see what the problem is...I just see someone suggesting a potential solution, the same way many of us do who have also never used the suggested product.

If hobbyvac gets yelled at for doing so, then I (and others) would probably deserve banning for all the times we've done it. :(
 
Hobbyvac is obviously prompting one particular product, so it is easy to believe that there is some sort of commercial interest involved.
What he promotes needs closer examination. So far, it's just vaporware.
 
I don't really see what the problem is...I just see someone suggesting a potential solution, the same way many of us do who have also never used the suggested product.

If hobbyvac gets yelled at for doing so, then I (and others) would probably deserve banning for all the times we've done it. :(
My apologies to hobbyvac and others. I read the post and got interested in the build, but there was no info in any of the threads, so I asked. From the way the posts read, it sounded like advocating for one system over another would be supported by something more than an aliexpress link.
 
My apologies to everyone as well,.. I will be more careful not to mislead. Communicating through text is harder and you can't always read intent correctly. My enthusiasm for those motors is only because they fit my small ATV application perfectly. I have been following and researching them as my posts suggest. Always asking for more info or feedback which has been sparse but good. For some reason they are used in many small bikes outside the US market and have been around for a while but are not well known here so I thought I would share a source. They are certainly no breakthrough technology or high performance but neither are hub motors. They are however a fairly cheap bolt in conversion for anything with a pit bike motor.

I challenge all keyboard conspiracists to link me to the company in any way, Actually, maybe they can get me a discount for my emotional trauma. THAT WAS A JOKE!! We do this for enjoyment, let's not be so serious. I will post feedback this summer when I get to it. My hope is to use a Surron controller and battery to get about 5000 watts out of it in bursts. The controller it comes with is way oversize so it may be easy enough to tune it up if the battery is up to it.
 
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