Mid-Drives - A Disaster for Trikes (Blind Leading the Blind)
Rakesh Dhawan on 6th May 2019
Mid-drive technology for bicycles and trikes is a step backwards for humanity. The only reason it exists today is that a "Big Company" became a strong proponent and manufacturer of it. It has no business in the bicycle world and no place in the trike world.
Mid-drive technology push is "Blind leading the Blind." We cannot let inferior technologies win.
We cannot let "big companies" kill innovation because of their deep pockets and prior brand history. We intend to stop this nonsense and continue to fight against big companies and "innovation killers."
The Significant Disadvantages of Mid Drives:
Where should I start? The list is virtually endless.
- Chain Failures: Because of the significant torque transmission, the chains become a weak link. Do you know special chains have been made making the whole offering much more expensive. Why are we letting the "Blind lead the Blind?";
- Gear Shifting Issues: Shifting of the gears becomes more difficult and derailleurs are prone to failure as now you are transmitting not only rider torque but the motor torque as well. Do you know after two recalls and six years in development, "the Big Company" can introduce easy shifting. It does not solve the problem: it eases it. That is the level of innovation of these big companies;
- Gear Failures: Plastic gears used inside the drive system remain prone to failure. The complexity and a large number of parts inside a mid-drive system are intolerable. Steve Jobs must be turning in his grave to see such a poor concept win in the market;
- Noisy Drives: Significant noise is introduced while the drive system is active due to high-speed operation of the motor and presence of gears. This noise will increase as manufacturers try to reduce the size of the drive and claim more torque. In my opinion, this is intolerable. This destroys the purity of a bicycle completely. Do we really want a motor cycle complexity on a bike?;
- Loss of Multi-Speed Front Gears: The front multi-speed gears are lost;
- Poor Sizing of the Front Gear: The size of the front gear is an issue in the transmission of power to the rear wheel. Human power is transmitted through the pedals and the length of the crank arm. Thereafter, the size of the front gear is crucial in transmitting that power to the rear. Bosh's first introduction was with the so-called "granny" gear and later this was resized to a bigger front gear for proper power transmission to the rear wheel. This is not an elegant solution;
- Reduction of Efficiency: Overall efficiency of the transmission of the power is reduced as the electric motor must transmit power through the internal plastic gears, the front gear, the chain, the derailleur, the free hub and then the wheel. That is a long path for power transmission as compared to direct drive motors;
- Loss of throttle Function: Although mid-drive systems can be operated with a throttle, this requires movement of the chain. This becomes significantly risky with high-speed open chains. This is no different from a motorcycle. Moreover, couple that the terrible noise. European mid drive systems such as Bosch does not have this capability.
- Loss of Regeneration: Mid-drives are not capable of providing regenerative braking as it would require reverse function of the motor as well as chain. Is regeneration important? Yes, it is quite important as braking should be
accomplished without wear and tear of the mechanical parts.
- Special Frame Design: Most mid-drive systems require a special frame design to accommodate the drive. This may not be a big problem for the large frame manufacturers but significant problem for small and medium scale manufacturers;
- Loss of the Bicycle: If your mid-drive system is down, then you are down. Whereas with direct drive, one can simply replace the rear or the front wheel. This may not be a big issue with some of the customers but it is significant for others. Some mid-drives can be installed on existing frames. However, the installation of those drives is significantly complicated.
- Limitation of the Product Offering: Level of customization is fairly significant with a mid-drive system. Currently, the eBike market is less than 10% of the overall bicycle market. So the end user is stuck with the eBike styling offered by manufacturers. End users should have more choices.
I have not even discussed the warranty, expensive repairs, return on investment and a very limited life time of mid-drives. It is truly a shame that such a concept is allowed to exist in the market place.
So, what does a mid-drive system bring to the table exactly?
Mid-drives can be made smaller by continuing to spin the motor to higher and higher speeds. This significantly shortens the lifetime of all the mechanical parts. Nevertheless, in a mountain bicycle, they help to keep the weight lower in the middle of the bike. Therefore, we have better stability while hill climbing.
How many of you are mountain goats? If you are not a mountain goat, there is nothing a mid-drive can do for you.
So, what does a mid-drive system bring to a Trike exactly?
This is "the Blind" leading the sheep or should we say the Wolf leading the sheep. The sheep want the security of a big company. They could care less about technology or innovation or what is right for the end user. Their goal is to follow the herd and be "Safe."
Which is more stable?
Center of Gravity for a Tadpole Trike without any eBike System
Understanding Dynamic Behavior and Trike Stability
In the article at jetrike.com, the author talks about the dynamic behavior of a tadpole trike. The author states:
“The tadpole rider's CoG is lower but located ahead of the forward tipping axis so it would tip forward under a 1g braking force. With modern caliper brakes, this would tend to lift the rear wheel. On a downward slope the tipping threshold would be even less, exacerbating the problem.”
Intuitively, one can conclude that having a direct drive motor actually improves the stability of a tadpole trike. The mid-drive motor will add significant weight to the front boom exacerbating the stability issue. The figures below illustrate this in a better fashion.
Where Mid-Drives cannot go?
IBM used to be the target of Steve Jobs when Mac was launched. And for several years the Wintel consortium could not deliver the key technologies. They copied and copied and took several years to reach Apple's product performance and elegance or Wait, Have they?
Here is the bad news. We cannot make a Lion out of a Donkey. Can we?
A mid-drive technology can never integrate into a virtual reality technology platform such as Zwift. Only Falco's eDrive has that capability. Have a look.