Something Else To Consider On Your E-bike
You’ve heard enough about hub motor questions. They are cheap and are here to stay. I’m seeing remarkable reliability out of the lower powered units. In fact, I haven’t needed to change a controller or replace reduction gears on anything 500 watts or less in the last five years.
As you can see, in the photo, most hub motors have something called reduction gears. They’re necessary if you hope to have significant torque. These can get stripped, which is more likely when you throttle ride, don’t shift properly or if your motor just gets hot.
Even most e-bike shops don’t know the same gears are used on 250 and 1.5kw hubs! I was surprised to learn that most aren’t aware that the mfg’s expect us to pull them apart and re-lube them every 1k to 3k miles (would any shop do so for less than $100?)! For many that is just too much hassle and time out of the saddle.
The fact is, in China, where almost all are made, the maximum wattage is 400 (at 48 volts). China is not only the largest e-bike market and the fastest growing, it already utilizes more e-bikes than the rest of the world. They aren’t investing in special tooling to suit The U.S. We are the 4th largest market after China, India and The EU. We might even be 5th if you consider the rest of Asia. Your hub motor, no matter how powerful, is designed with components for 400 watts (roughly 700 peak) and roughly 45nm’s of torque.
Now, this problem doesn’t extend only to Chinese hub motors (are any others more than 500 watts?). I am beginning to see it in more powerful mid-drives. Perhaps it isn’t as pronounced because they are less dependent upon their tiny motor for torque (much more delicate than a hub motor). Perhaps it is easier to adjust with intenal components (certainly their price makes it more cost effective).
Like their gasoline powered cousins though, higher powered mid-drives seem to be tearing themselves apart. The few that stand up best are heavy (cumbersome) and their torque sensing, where they have it at all, is delayed. It seems to be more like an on/off switch or a bad throttle.
I get it, some have been able to make theirs run for 10’s of thousands of miles. My buddy has a heavy, cadence based 750 watt mid system, on a cargo bike, that must have 20k miles by now (he’s also an expert cyclist and has no interest in speed or throttle riding). For many, speed and power trump handling and reliability. Most struggle to maintain their entire drive train. I have to wonder, except for illegal speeds, do we even have a use, much less a need, for that kind of power?
I look at foks with 250-500 watt systems. These are closer to what you find in the countries mfg’ing their motors. The vast majority just aren’t having the problems we see on higher powered systems in The U.S.
I’ve built everything. I still can sell everything, but I am beginning to have second thoughts even on legal Class III systems. Have most ever ridden a lower powered bike to compare? Properly programmed, I’m just not seeing that big of a difference. 250 watt mid-drives and 350 watt hub drives, for most daily applications, seem to be just as good as their more powerful, but less reliable counterparts. They get better range. They handle better, are quieter and I almost never see lower powered systems for repairs.
I swear, I am just rumonating here, but maybe we should be taking this seriously when choosing an e-bike. I know I am going to be more cautious in my custom builds. I’m also going to give lower powered hub drives more consideration moving forward.