Top Speed of Bafang Ultra vs. JuicedBikes CCX

I've read on another forum that the JuicedBikes CrossCurrent X can get up to 37 mph on the highest level of assist. What is the maximum speed with the Bafang Ultra? I'm leaning towards the Bafang Ultra since it has throttle assist past 20 mph, the limit on Juiced Bikes' models.

I'm referring to top speed while pedaling on flat terrain, not uphill or descending.

The Bafang Ultra isn't a bike, its a 1000W mid drive system that peaks over 2000W depending on the bike configuration that uses it.

The JuicedBikes Crosscurrent X is a bike, one that uses a Bafang 750w geared hub motor. With a 52v battery and a 25A peak current its likely peaking at about 1500W of power give or take. 37Mph would take a lot of peddle power I would say.

Most bikes running the Bafang Ultra would be more powerful and faster than the CCX.

CCX and RCS (RipCurrent S) owners report varying top speeds. Some claim the motor only assists up to 30 mph, others say they can get up to 33 mph, but at least one rider says they can get up to 37 mph. I've seen a RCS video where the rider gets up to nearly 30 mph but he is pedaling very hard, exerting a lot of effort.

Without test rides, it's impossible to say whether these claims are just hyperbole for bragging rights or legitimate top speeds, perhaps in ideal conditions (strong, light rider with light headwinds, slightly downhill).

I have the Ultra motor in my own frame. The gearing isn't massive - 44t front to 11t on the back in the biggest gear.

If I pedal hard I can get the bike upto 32mph and at that point the only limiting factor is how fast my legs are spinning.

If I fitted a 50t+ ring on the front I am confident the motor would still assist upto the point I am spinning out, there is so much torque from it.

There is a top speed setting on the menu which is 60mph maximum, I am not sure whether that means anything tbh.

Air Resistance is a limiting factor. The faster you go the more air resistance, so getting into an aerodynamic position you can gain more.

The Ultra with a high gear ratio will be faster.

I use Schlumpf drives on my two 52v/20A hub bikes. One has a Speed Drive that is equivalent to a 44t and at 28mph pedaling loses effectiveness fast but the motor will pull to >30 in ideal conditions.

The High Speed drive has an equivalent 68t, both 11t rear cog btw, and provides for active pedal input up to >35 with the hub at max output.

So gearing is important to both obviously but I haven’t seen any Juiced bike with the big chainring necessary to pedal effectively at 37mph but doesn’t mean there isn’t one.

I was curious a few years ago after averaging close to 30mph for a batteries worth a few times if it was possible and it took a few more tries but under ideal conditions, little wind, paved road with little traffic and no stops hit it but at the expense of 30wh/mi using 520whs for a bit over 17 miles.

markz said:

Air Resistance is a limiting factor. The faster you go the more air resistance, so getting into an aerodynamic position you can gain more.

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This is a very valid point, most people who do testing will tell you that up to 20 mph there is very little aero drag to deal with, and it gets more and more of an issue above 20 mph. At 30+ mph, your aero drag goes up exponentially!

That said, the limiting factor is the motor, a 750 watt (geared? DD?) hub motor can certainly be capable of high speed with the right controller, battery and 37 mph is quite possible, but that's not really that impressive, I could get 37 MPH on a 700c road hybrid with skinny tires powered only by a 750 watt BBS02 (nominal settings, not hot-rodded) but I am in decent shape and lighter than some, a friend of mine was able to make the same E-Bike go 42 MPH, but there again, that means nothing because half of that speed is due to his being an avid cyclist with loads of leg strength.

If you really want to test E-Bikes head to head, do no pedaling tests, motor power only, otherwise you're not going to get any real useful data.