Plenty of people go looking for Surron Ultra Bee brake specifications, and they mostly come away with nothing. There is a straightforward reason for that, and we would rather tell you than pretend otherwise.
Start here
Surron does not publish brake specifications for the Ultra Bee. We checked their official specification sheets for both the standard Ultra Bee and the Ultra Bee HP. Both list dimensions, motor, battery, suspension travel, tyres and frame material. Neither lists caliper piston count, rotor diameter, master cylinder or brake brand.
So any page quoting you an exact Ultra Bee rotor size is quoting something other than the manufacturer. We are not going to add to that pile. Here is what is actually documented.
What Surron does publish about stopping the bike
The braking information on the Ultra Bee HP specification sheet is all electronic, and it is more substantial than most buyers realise:
| Function | What Surron states |
|---|---|
| Braking regeneration | 5 level adjustable |
| Coasting regeneration | 5 level adjustable |
| Brake priority | Brake priority setting with override protection |
| Traction | ASR |
| Hold | Auto hold |
| Friction brakes | Not specified on the published sheet |
That matters more than it looks. On a bike with two five level regen systems, coasting and braking, a large share of your everyday deceleration is being done by the motor rather than by pads and rotors. Turn regen up and more of your deceleration goes through the motor instead of the pads. Riders who turn it off, or who ride steep technical descents where regen saturates because the battery is already full, put everything through the friction brakes and find out quickly how good they are.
The one that catches people out
Regenerative braking weakens when the battery is near full. Start a ride at the top of a long descent on a 100 percent charge and your regen has very little room to put energy, so the bike feels like the brakes got worse overnight. They did not. Ride a few minutes on the flat first, or charge to around 90 percent before a big descent day.
Brake priority, and why your throttle cuts out
Surron lists brake priority with override protection on the HP, but publishes the function name rather than its behaviour. In practice on these controllers, brake input active means drive is cut regardless of what the throttle is asking for.
This is a safety feature and it is a good one, but it surprises riders coming from a gas bike, because it means you cannot drag the rear brake while on the power in a turn the way you might on a two stroke. If you notice the bike going dead when you brush the brake lever, that is the system working as designed, not a fault. It also means a dragging or badly adjusted brake lever can feel like a power problem. Always rule out the brake switch before you start suspecting the controller.
Pads: one part fits both of our 74 volt bikes
Here is something useful that we can state from our own parts data rather than from a specification sheet. The brake pad we stock is a single part that fits both the Surron Ultra Bee and the Arctic Leopard XE Pro R.
That tells you something the spec sheets do not: these two machines use a compatible pad footprint. It is a common pattern in this class. It also means that if you run both bikes, or if you ride with someone who runs the other one, one spare set covers you both.
Brake pads for Ultra Bee and XE Pro RWhen to change pads on a bike this heavy
These are not bicycles. An Ultra Bee HP is 195 lb before you sit on it, and it will reach speeds in the fifties. Pad wear is closer to small motorcycle territory than to mountain bike territory, and the consequences of leaving it are worse.
Change pads when friction material is getting thin, when braking becomes noisy in a way that does not clear after a few stops, when lever travel grows, or when you can see uneven wear between the inner and outer pad. Contaminated pads, usually from chain lube or brake fluid, do not recover with cleaning in our experience. Replace them. And always replace pads as an axle set rather than one side.
Bed new pads in before you need them
Fresh pads do not make full power until they have transferred a layer of material onto the rotor. Do a series of moderate stops from a moderate speed on a safe, clear, flat surface, letting the brakes cool between them, and avoid dragging to a complete standstill while hot. Do not discover your new pads are not bedded at the top of a descent.
Brakes are a safety system. If you are not confident doing the work, have it done. Riding is a risk activity and you are responsible for your own machine.
How the Arctic Leopard compares, since we stock both
Unlike the Ultra Bee, the Arctic Leopard XE Pro R does have a published brake specification: four piston hydraulic calipers on 240 mm rotors. We can state that because it is on our own product page for the machine we ship.
We want to be careful about what that does and does not prove. A published figure beats an unpublished one for a buyer trying to compare, and four pistons on a 240 mm rotor is a serious specification on a 175 lb bike. But an unpublished brake is not automatically a worse brake. It is an unpublished one. We have not measured stopping distance on either bike, and we are not going to turn rider impressions into a measurement.
If you are weighing the two machines overall rather than just their brakes, we wrote a full Ultra Bee versus XE Pro R comparison, and we stock both so there is no thumb on the scale.
See the Arctic Leopard XE Pro R See the Surron Ultra Bee HP SW