Hub MOtor
Rear wheel Hub Motor
A rear wheel hub motor is a great option for electric assist due to its affordability, easy installation, and advanced controller systems. However, the crucial question is: how much power is actually needed?
From our testing, motors rated at 1500 watts (2 HP) or more are often excessive. Given the lightweight design of a velomobile, it requires minimal power to achieve efficient acceleration—especially when considering that an average person produces only 100-200 watts of power.
For everyday use, a 500-750 watt motor provides more than enough power.
How to replace brake pads on Avid bb5 brake
Changing Out BB5 Brake Pad
Changing out BB5 brake pads is easy. Watch this short You tube link below:
Internal gear hub
Shimano Internal Gear Hub
The Shimano Alfine is a high-end internal gear hub system designed for urban and touring bikes. Known for its smooth, reliable shifting, the Alfine offers a clean, low-maintenance drivetrain solution with a sleek appearance. Available in both 8-speed and 11-speed versions, the Alfine hub provides a wide gear range and precise gear changes, making it ideal for commuters and long-distance riders.
Key features include:
- Sealed internal mechanism: Protects against dirt, moisture, and debris for consistent performance and durability.
- Silent, smooth shifting: Provides a more refined ride, especially in city environments.
- Disc brake compatibility: Available with hydraulic or mechanical disc brake options, offering excellent stopping power.
- Optional Di2 electronic shifting: The Alfine 11-speed version is compatible with Shimano's Di2 electronic shifting system for faster, more precise gear changes.
The Shimano Alfine combines advanced technology with an elegant design, making it a favorite for those seeking performance and practicality in their cycling setup. Cost is ~$200
Shimano Internal Gear Hub
1. Shimano Alfine 8-Speed (The Value Option)
The Alfine 8 is the ideal entry point into Internal Gear Hubs (IGHs). It is built around a simpler mechanical design that uses grease for lubrication.
- Trade-offs: The gear range is $\mathbf{307\%}$, which is sufficient for urban riding and gentle hills but may leave serious tourers needing a lower climbing gear or a higher top gear. The gear steps are uneven, meaning the jump between one gear and the next might feel larger or smaller depending on where you are in the range.
- Maintenance: It is famously durable and low-maintenance, though a full internal re-grease service is a complex, hands-on task best left to a shop. The hub mechanism is less complex, which contributes to its robust reputation, especially for e-bike use.
2. Shimano Alfine 11-Speed (The Enthusiast's Compromise)
The Alfine 11 is Shimano's attempt at a higher-performance IGH, featuring an 1$\mathbf{409\%}$ gear range that is a massive step up from the 8-speed and suitable for light touring.2
- Key Upgrade: It uses a sealed oil bath for lubrication, a major upgrade that simplifies maintenance.3 The annual oil change is a relatively easy DIY task (similar to an automotive oil change) that flushes out contaminants.
- Trade-offs: The 11-speed is more sensitive to cable tension than the 8-speed, and some riders report a greater internal drag in certain gears. While the steps are mostly even, there is a large initial jump, and long-term reliability reports are more mixed than the 8-speed or Rohloff. It sits in a crucial middle ground, but its performance doesn't match the Rohloff's precision.
3. Rohloff SPEEDHUB 500/14 (The Expedition Standard)
The Rohloff is the top-tier, precision-engineered choice. Its cost reflects its extreme durability, wider range, and superior engineering.
- Performance: It offers the widest range. This allows a rider to maintain an ideal pedaling cadence no matter the terrain, which is essential for long-distance touring. Its extremely low gear ratio (0.279) provides excellent torque multiplication for climbing steep hills with a fully loaded bike.
- Longevity: The hub's internals are made of hardened steel and are designed to function for decades.7 Its sealed oil bath system is proven to keep out water and dirt, making it the choice for world travelers who ride in all conditions. The price is its main barrier to entry, but for a high-mileage rider, its low long-term maintenance costs and near-indestructible nature often justify the expense.
Rohloff Speed Hub
The Rohloff Speed hub is a premium internal gear hub renowned for its durability, precision engineering, and wide gear range. Developed by Rohloff AG in Germany, the Speed hub is a popular choice among touring cyclists, mountain bikers, and commuters who value low maintenance and high performance. Offering 14 evenly spaced gears, the hub delivers a vast range with seamless shifting, comparable to traditional derailleur systems but with significant advantages in terms of reliability and upkeep.
Key features include:
- 14-speed transmission: The Rohloff Speed hub provides a broad gear range (526%) with equal steps between gears, making it suitable for steep climbs and fast descents alike.
- Sealed system: The fully enclosed design protects the internal mechanism from dirt, water, and debris, ensuring reliable performance in all weather conditions and requiring minimal maintenance.
- Durability: Built to last for tens of thousands of miles, the Speed hub is engineered for longevity and is a favorite for long-distance tours and expeditions.
- Twist shifter: Unlike derailleur systems, the Rohloff hub uses a twist grip for rapid and precise gear changes, allowing the rider to shift through multiple gears at once, even while stationary.
- Maintenance: Only requires an oil change every 5,000 km (or annually), making it highly convenient for long-term use.
The Rohloff Speed hub is often considered the pinnacle of internal gear hub technology, offering unparalleled reliability, making it a premium choice for cyclists who demand top-level performance with minimal maintenance.
Cost is $1400+
Nuvincci CVP Hub
The N330s continuously variable transmission allows you to change the gear ratio in one continuous motion - just twist the shifter and the gear ratio is changed to any ratio within its 330% range. Whether pedaling under a load, shifting while stopped or waiting at a stoplight, The N330 will shift and is eBike and Belt Drive compatible.
- 330% Nominal Ratio - 0.5 underdrive to 1.65 overdrive
- Compatible with mid-motor ebike systems rated at 250W or less
- Designed for minimal maintenance
- Use only 3/32” chain and cogs
- Compatible with Shimano 9-Spline Single Speed Sprockets
- cost under $150 on sales
Wheel Size Selection 20" vs 26"
Smaller Wheels (Typically 20" or smaller):
- Advantages:
- Compact and lightweight: Contributes to a lighter overall velomobile, improving acceleration and climbing ability.
- Lower center of gravity: Enhances stability, especially in tight turns.
- Increased maneuverability: Ideal for navigating crowded areas and tight spaces.
- Disadvantages:
- Harsher ride: Smaller wheels are more susceptible to bumps and vibrations.
- Lower top speed potential: May limit high-speed cruising efficiency.
- Increased rolling resistance: Can require more effort to maintain speed on smooth surfaces.
- Best for: Urban commuting, tight courses, velomobiles where compactness and maneuverability are paramount.
Larger Wheels (Typically 26" or larger):
- Advantages:
- Smoother ride: Larger diameter wheels absorb bumps and vibrations more effectively.
- Higher top speed potential: Better rolling efficiency at higher speeds.
- Reduced rolling resistance: Less effort required to maintain speed on smooth surfaces.
- Disadvantages:
- Larger and heavier: Can increase the overall weight of the velomobile, affecting acceleration and climbing.
- Higher center of gravity: May slightly reduce stability, particularly in sharp turns.
- Reduced maneuverability: Less agile in tight spaces.
- Best for: Touring, long-distance riding, velomobiles where speed and comfort are prioritized.
Considerations:
- Frame Design: Your velomobile's frame will dictate the range of compatible wheel sizes.
- Rider Size and Weight: Heavier riders may benefit from larger wheels for increased strength and stability.
- Terrain: Consider the type of terrain you'll be riding on. Rough roads favor larger wheels, while smooth roads allow for more flexibility.
- Gearing: Wheel size affects gearing ratios. You may need to adjust your gearing to optimize performance with different wheel sizes.
3R Engineering offers a variety of velomobile designs that can accommodate different wheel sizes. Contact us to discuss your specific needs and we can help you choose the perfect wheel size for your project!
CARBON FIBER USED IN VELOMOBILE BODY
Here's a summary of what the chart shows:
- Purpose: It plots different grades of carbon fiber to show how their tensile strength and modulus vary. The chart specifically highlights U.S.-produced carbon fibers with red dots.
- Groupings: The fibers are categorized into three main zones based on their modulus:
- Orange Zone (Standard Modulus): These fibers have a lower tensile modulus (roughly 30-45 Mpsi) and moderate tensile strength (around 500-800 ksi).
- Green Zone (Intermediate Modulus): These fibers exhibit a higher modulus (roughly 45-60 Mpsi) and high tensile strength (above 800 ksi).
- Purple Zone (High Modulus): These fibers have the highest tensile modulus (above 60 Mpsi) but generally lower tensile strength (below 700 ksi) compared to the other groups.
- Trade-off: The chart visually demonstrates a common trade-off in materials science: as the stiffness (modulus) of carbon fiber increases, its tensile strength tends to decrease.
- Specific Grades: Individual grades are labeled, such as T300, T700S, T800H, T1000G, M35J, M40J, etc., showing their specific position on the graph.
In essence, the chart is a visual reference for engineers and designers to select the appropriate carbon fiber grade based on whether their application requires higher strength or higher stiffness.
Aerodynamic advantage of Velomobile
- Chart form right is from a technical paper by the University of Virginia on Human powered recumbent vehicle design. The analysis evaluated the impact of various factors on power output, focusing on drivetrain components and vehicle characteristics. It was found that adding a fairing to the design reduces the rider’s required power output for climbing hills, despite increasing the vehicle's weight by about 5 kg. The decrease in drag from the fairing makes it beneficial overall, as it results in lower power demands compared to not using the fairing during endurance events.
The cost of building Velomobile
- Building a velomobile yourself can cost anywhere from a few thousand dollars to significantly more, depending on the materials used, complexity of the design, and whether you source parts yourself or buy pre-made components; a basic DIY velomobile could cost around $2,000 - $5,000, while a more advanced custom build could reach upwards of $10,000 or more.
- The material costs for the University of Virginia's HPV project (2020) totaled $4,065, excluding labor and experimental losses. The price of carbon fiber, in particular, has surged significantly since the pandemic, with some grades now costing nearly twice as much as they did just a few years ago.
What is Ackermann?
- Ackermann compensation refers to the design principle in vehicle steering geometry that ensures all wheels of a vehicle, particularly the front wheels, pivot at appropriate angles when turning. This allows the inner and outer wheels to trace different arcs, compensating for the fact that the inner wheel must turn at a tighter radius than the outer wheel to prevent tire scrubbing and improve cornering efficiency.
- When a vehicle turns, the inside wheel follows a smaller, tighter circle, while the outside wheel follows a larger, wider circle.
Effect of Camber on Velomobile
- The camber angle on a recumbent trike refers to the angle at which the wheels are tilted relative to the vertical axis when viewed from the front or rear. This angle can significantly impact the trike's handling, stability, and performance.
- The optimal camber angle for a recumbent trike depends on the intended use, rider preferences, and specific design considerations. A slight negative camber is often preferred for performance-oriented trikes to enhance cornering and handling, while a neutral or slight positive camber might be better for stability and comfort, especially for long-distance touring or casual riding. Adjusting the camber angle should be done carefully, considering the trade-offs between stability, handling, tire wear, and aerodynamics.
How to repair a flat wihtout removing the wheel
- Remove the outer tire and carefully take out the inner tube.
- Inflate the inner tube slightly to locate the leak. Listen for escaping air or submerge the tube in water to identify the exact spot of the puncture.
Apply a thin, even layer of adhesive to both the inner tube and the patch. Wait for about 5 minutes until the adhesive becomes tacky before proceeding
Firmly apply the patch to the inner tube, pressing down evenly. Apply a thin layer of adhesive around the edges of the patch for extra seal. Allow it to cure for at least 6 hours, then inflate the tube to test for any leaks