Does RAD's have a governor? Stock top speeds?

[Joe Caronia]

Hey, I'm just wondering if you can use pedal assist and go faster then 20mph? I always hear 20mph when talking about these bikes but I never hear anything over that. I would imagine that pedaling downhill even with the motor going I could reach beyond 20mph, is this true? Is so, what are some of your guys stock speeds? And/or is there any ways to go faster? Thanks!

 

[thatdude902]

Stock speed it 20 mph, that's supposed to be the legal limit. But there is a setting you can set, in setup mode, where you can set it to 40 kph which corresponds to 24.85 mph. And also set the wheel size to 28" while you're at it.

And yeah, it's not that hard to pedal fast enough in the highest gear and PAS 4 or 5 to go over 20 mph, even in flat ground.

 

[Jeff185]

On level ground, with the controller set at 28 inch wheel size and 40kph, I can go 24.6 MPH while aggressively peddling with peddle assist level 5. I'm shrinking as I age, about 150 lbs. Without hacking the controller and adding a higher voltage battery, I haven't heard about any way to increase speed.

 

[Barkme Wolf]

There are hacks but they void your warranty. The ones I have seen involve physical modifications to the sensor systems. Not sure how it all works myself.

 

[cbmojo]

curious, where have you seen them?

 

[Barkme Wolf]

curious, where have you seen them?

Youtube

 

[walawn]

Divide by 2 circuit for the speed sensor, change your top speed via LCD display, change tire size via LCD display, change rear cassette, lighten wieght, or just do what I did and install BBSHD haha (instant 40 mph, or 30 mph if geared low)

 

[Barkme Wolf]

Divide by 2 circuit for the speed sensor, change your top speed via LCD display, change tire size via LCD display, change rear cassette, lighten wieght, or just do what I did and install BBSHD haha (instant 40 mph, or 30 mph if geared low)[/QUOTE

Please elaborate. On changing the "size", I assume you mean tire size, won't that make the MPH readout inaccurate? Not sure what it is to divide a circuit. The other modifications you suggest can get more speed out of any bike but won't up the speed generated by the motor. The BBSHD, are you suggesting installing a second motor?

 

[walawn]

@Barkme Wolf Adding a "divide by two" circuit would take the input from the speed sensor and basically divide it by half so the output is half of what the sensor should receive. If you have any EE friends, they could possibly make you one. I think the speed sensor for the Radrover is based off of what RPM the rear wheel (read: hub motor) is doing. So intercepting and modulating that signal could be one way to potentially gain more top speed. The challenge would be in diagnosing and accessing how the system as a whole does that. My 60 lb. Radrover would do around 22 mph with a 180 lb. rider (me!). Now from all my research, the stock Bafang 750W geared hub motor is only good for around 20 mph and kind of putters out past that point. That is due to how the motor is internally wound. You cannot change that. Less windings and thicker wire grant you more top-speed while more windings and thiner wire grant you more torque. The RM G06.750.DC Bafang motor is somewhere in the middle of those two extremes. If you had the capability to add increasing amounts of amperage, the motor would eventually reach the maximum RPM that it could attain. You are limited by the design of the motor essentially. Changing the tire diameter in the display settings could potentially alter the top speed by "tricking" the controller to apply more power at a higher speed instead of cutting it off once it reaches 24.85 mph (or 40 kph as is the limit in the speed settings). The way to check this would be with GPS to determine your true speed. Try it at 24", 26", and 28" wheel settings and see what kind of results you get. As far as the BBSHD goes, I went that route personally becasuse I was limited by the rear motor and factory controller. I didn't see a way around this so I opted to remove the rear motor (lighter weight and less drag), install a larger 52V battery (which helped me back when it was stock to gain a couple of mph), 11-32 freewheel cassette (better gearing and less drag), and install the BBSHD mid-drive conversion kit (30+ mph with 42T front sprocket or 40+ mph with 46T sprocket). They do make a 30T and a 52T for the BBSHD, but I feel like the 42T is where the best combo of gearing is (especially with my new cassette in the back).

(Link Removed - No Longer Exists)

 

[Mark in CA]

@Barkme Wolf Adding a "divide by two" circuit would take the input from the speed sensor and basically divide it by half so the output is half of what the sensor should receive. If you have any EE friends, they could possibly make you one. I think the speed sensor for the Radrover is based off of what RPM the rear wheel (read: hub motor) is doing. So intercepting and modulating that signal could be one way to potentially gain more top speed. The challenge would be in diagnosing and accessing how the system as a whole does that. My 60 lb. Radrover would do around 22 mph with a 180 lb. rider (me!). Now from all my research, the stock Bafang 750W geared hub motor is only good for around 20 mph and kind of putters out past that point. That is due to how the motor is internally wound. You cannot change that. Less windings and thicker wire grant you more top-speed while more windings and thiner wire grant you more torque. The RM G06.750.DC Bafang motor is somewhere in the middle of those two extremes. If you had the capability to add increasing amounts of amperage, the motor would eventually reach the maximum RPM that it could attain. You are limited by the design of the motor essentially. Changing the tire diameter in the display settings could potentially alter the top speed by "tricking" the controller to apply more power at a higher speed instead of cutting it off once it reaches 24.85 mph (or 40 kph as is the limit in the speed settings). The way to check this would be with GPS to determine your true speed. Try it at 24", 26", and 28" wheel settings and see what kind of results you get. As far as the BBSHD goes, I went that route personally becasuse I was limited by the rear motor and factory controller. I didn't see a way around this so I opted to remove the rear motor (lighter weight and less drag), install a larger 52V battery (which helped me back when it was stock to gain a couple of mph), 11-32 freewheel cassette (better gearing and less drag), and install the BBSHD mid-drive conversion kit (30+ mph with 42T front sprocket or 40+ mph with 46T sprocket). They do make a 30T and a 52T for the BBSHD, but I feel like the 42T is where the best combo of gearing is (especially with my new cassette in the back).

(Link Removed - No Longer Exists)

Thanks for all the info, would love to do all this as parts wear or fade. Does your bike still weigh 60lbs?

 

[walawn]

@Mark in CA I haven't had a way to weigh it yet. Maybe my LBS has a scale or something. I would be interesting to know how it's changed.