Velociraptor E-Bike

Appearance

🏍️ Motor ​

The LR SB (Lightning Rods Small Block) is a DC brushless motor with an IPM rotor structure. That enable it to be hit with large amounts of flux or field weakening to attain high RPMs without the risk of magnets becoming detached or damaged from the high centrifugal forces.

Dimensions: 127mmx127mmx78mm Weight: 3kg Voltage Range: 36V-100V kV: 67 rpm/volt Operating amps: 50A continuous, 90A burst

The LR Ultra is a complete small motor system that includes a belt/chain drive and a rear disc/sprocket system.

Ratio ​

Motor (18T) ↓ belt 1 Intermediate shaft (90T + 36T) ↓ karting chain Rear wheel (66T)

Stage 1:

  • Motor pulley (driver): 18 T
  • Driven pulley: 90 T

90/18 = 5

Stage2:

  • Driver (on same shaft): 36 T
  • Driven (rear wheel): 66 T 66/36 = 1.8333

5.000Ă—1.8333=9.1667

Ratio is exactly 9.1667 Reduction: 9.17:1

Motor Pulley: 60 Wheel Pulley: 550

Performance and Comparison ​

How does the Small Block (SB) compare to the BBSHD in terms of torque and acceleration? ​

  • The SB has nearly twice the torque of the BBSHD.
  • The BBSHD produces 7 ft-lbs of torque at the motor shaft, while the SB delivers 12 ft-lbs.
  • The SB is designed for proper motor gearing, unlike the BBSHD, which relies on overdrive gearing, leading to wear on bicycle chains and sprockets.
  • The SB significantly outperforms the BBSHD in acceleration.

Real Torque vs Claimed Torque:

BBSHD advertises 160Nm, but that is measured after a 22:1 reduction, resulting in only ~7Nm at the motor shaft.

The SB produces 16Nm at the motor shaft, nearly twice the usable torque of the BBSHD without relying on heavy reduction gears. Efficiency and Speed:

Gear-heavy motors like the BBSHD generate torque at low RPM, giving legal-speed compliance but limited acceleration.

The SB delivers higher torque at higher RPMs, allowing faster acceleration and higher top speeds with minimal drivetrain stress.

Weight and Design Advantage:

Small motors with heavy internal gears are heavier because of torque multiplication mechanisms.

The SB is lighter, more efficient, and durable, achieving strong performance directly at the motor shaft, reducing wear on chains and sprockets.

What is the top speed of the SB? ​

  • The SB can achieve speeds of up to 90~100km/h when properly configured.

Motor and Chain Information ​

What type of chain does the SB use? ​

  • The SB uses a #219 kart chain instead of a bicycle chain.
  • The pitch (pin-to-pin distance) of the 219 chain is 0.306 inches, compared to 0.500 inches for bicycle chains.
  • The 219 kart chain is wider, stronger, and more durable.

How should I maintain the 219 kart chain? ​

  • Use spray-on chain wax for lubrication.
  • A #219 chain tool is required to open and join the chain.
  • Hot wax treatment can be used as well.

Purchasing and Availability ​

What output axle sizes are available? ​

  • There are two standard sizes: 12mm and 15mm.
  • The Ultra version of the SB has a special 15mm axle designed for the Bafang M620 replacement drive.

Controller and Power Configuration ​

What are the SB’s electrical specifications? ​

  • Kv (RPM per Volt): 67
  • Pole Pairs: 5
  • Hall Sensors: Positioned at 120-degree angles
  • Recommended max phase amps: 100A
  • Recommended max battery amps: 60A @ 84V
  • The SB can handle 6kW continuously without overheating under normal conditions.
  • It supports 90A burst current.

What is the maximum safe operating temperature for the SB? ​

  • 77°C (170°F) is the recommended maximum temperature.

Can the SB overheat? ​

  • The SB runs cool at 3kW.
  • At 6kW, it may start to get warm on long, high-speed hill climbs.

What is the advantage of the SB over other motors? ​

  • Higher torque and better acceleration than the BBSHD.
  • Stronger and more durable 219 kart chain drive.

Maintenance & Upgrades ​

Does the LR Small motor require maintenance? ​

  • The motor itself requires no maintenance.
  • The primary belt needs minimal care; just check the belt tension occasionally.
  • Use chain wax for the final drive chain.

Can I add Statorade to the motor? ​

  • No, Statorade is designed for outrunner hub motors, where heat is trapped inside the armature.
  • The LR Ultra is an inrunner motor, meaning heat dissipates through the aluminum case naturally. Adding Statorade is not needed or recommended.

Rear Disc & Sprocket ​

How does the rear disc and sprocket work? ​

  • The sprocket and rotor are designed as a single unit.
  • The assembly includes a custom laser-cut sprocket and a seven-bolt alloy spacer.

Is the rear disc compatible with standard six-bolt rotors? ​

  • The disc and sprocket are a unique design, not a standalone six-bolt rotor.
  • However, a six-bolt adapter is available for standard 219 racing kart sprockets, ranging from 65T to 94T.

Can I get a version without a rear brake disc? ​

  • Yes, a discless version is available.
  • If you don’t need the rear brake, you should order the 219 adapter without a brake, which is cheaper and simplifies installation.

Longevity & Availability ​

What happens if LightningRods stops making parts? ​

  • Currently, the sprocket and rotor unit is unique to LightningRods, meaning replacements must be sourced from them.
  • The upcoming spider adapter should improve compatibility with widely available crank arms.
  • The 219 sprocket adapter allows using common kart sprockets, reducing reliance on proprietary parts.