CRANK DRIVES – A DISASTER FOR TRIKES

I ran across this article and it backs up what I have been saying … why I favor hub motors over crank drive motors on a trike. It does not cover one of my main objections to crank drive but it does cover one important factor I never thought of … the matter of stability. Having all that weight mounted out on the end of the boom effects the handling and stability of the trike. On the other hand a hub drive in the rear wheel makes the trike more stable.

https://www.electricbicycleworld.com/blog/middrives-a-disaster-for-trikes-blind-leading-the-blind/

KEEP ON TRIKIN’

A FREE GIFT awaits you!

Author: Steve Newbauer

I have a few current blogs (tadpolerider1, navysight, truthtoponder and stevesmixedbag) so I am keeping busy. I hope you the reader will find these blogs interesting and enjoy your time here. Feel free to email me at tadpolerider2 at gmail dot com (@gmail.com)

One thought on “CRANK DRIVES – A DISASTER FOR TRIKES”

  1. Since the headline reads. Mid Drives – A Disaster for Trikes, I think this should have some counter points, especially since it was written by an exclusive hub motor maker. – Might just be a little biased don’t you think? First off I can tell you after 10 years of Tadpole Trike riding, touring, servicing, repairing & selling Trikes & Mid Drives, not once have I encountered a claimed ‘disaster.’ Certainly there can be problems but that is also true for hub motors & most of these problems have been either rider error or new product bugs. So to counter each one of the points expressed in this article I will express my experience & opinion based on installing &/or solving any problems that did occur. No power assist system is going to be perfect for every rider & each method has advantages & disadvantages. The key is to install a system that works the best for you, your riding conditions, your budget & exactly what you are expecting out of your Power Assist.

    Chain Failures – It is possible a chain can fail but it is unlikely if your chain is maintained, lubricated & you shift your gears properly. Using common sense should tell you that a 1500 watt hub motor should put more strain on your chain than a 350 watt Mid Drive.

    Gear Shifting – Can be a problem regardless of where the torque is coming from. This article seems to imply that the rider torque would somehow add extra torque to the chain making it prone to failure. If a Cadence Sensor is in use a simple Gear Sensor cuts your motor power as soon as your gear cable is moved. With a torque sensor as soon as you stop pedalling so does the power going through your chain.

    Plastic Gear Failures – In early Mid-Drives this was a problem as the heat in the motor would soften the Delrin or plastic gears. This seems to only be a problem now in some high power systems. Some Mid Drives have a fail safe Delrin Gear designed to fail before your motor burns up. This is a $25. repair that can be done at home. Using your gears & proper lubrication prevents the motor from heating up in the first place.

    Noisy Drives – A motor is a motor & gears are gears & if a decibel test was done on Hub Motors & Mid-Drives it would be a wash. Some systems are noisy but the majority make about as much noise as your rear derallieur gears.

    Loss of multi front gears – True but the higher level of torque you have from your motor the fewer low gears are needed. True for Mid or Hub Motors.

    Poor sizing of the front gear – Many Mid-Drives give you the option of what size single chainring you wish to use. You also have the option of installing a dual front chainring. You need to understand gearing & what it means to have the final drive at your back wheel to do your gearing right.

    Reduction of Efficiency – Again, available watts, gearing, weight being moved, quality of cells, quality of the components all play a part in the overall efficiency of your system. There are hub motors that are very, very good & some that are so bad you might get 6 months use out of them. There’s a reason why you can buy a motor kit off Ebay or Amazon for $300. while a Shimano, Bosch or Luna Cycle kit can cost $2000.

    Loss of throttle – A bit of a contradiction here. A throttle in Europe puts you in a different class of a Pedelec so most systems in Europe are sold without them. Unless you have the need for a throttle, they are simply an option but definitely not an essential requirement.

    Loss of regeneration – Quite true, but the amount of recovered energy put back into your battery is cancelled out by the extra weight & complexity of your electronic circuitry. Most Regen Systems do not free wheel (Coast) as well as a Mid-Drive since the motor magnets are always cogging past the armature causing resistance. This means you can extend your range by NOT using watts & should a repair ever be needed, because your system is less complex, you can do the repair yourself at home.

    Special Frame Design – Mid Drives for Trikes are available for common 68 mm bottom bracket shells that are the industry standard. You can also buy Mid-Drives with the Boom & special housing attached should you want one of the state of the art kits manufacturers are producing.

    Limitations of Product Offering – Well let’s see. Since it pertains to trikes, there would seem to be far more product selection for mid drives then there is for hub motors. You have Mid Drives from Bafang, Tongsheng, Dapu, Multinova, Bosch, Panasonic and others in various sizes up to about 2000 watts peak. Definitely seems to be enough product offerings.

    What does a Mid-Drive bring to the table? – How about more torque than any comparable Hub Motor & significantly more than any Direct Drive with regen built in. A 500 watt Mid Drive will deliver about 80 nm of torque compared to about 40nm for a hub motor. This means your system is not working nearly as hard as your hub motor to climb that mile long hill at the top of your street. How about ease of repairs? – If you need a repair to your Mid Drive you can plug & play most wearable parts after removing the side covers. On a hub motor, it almost always requires removing the wheel &/or more disassembly to troubleshoot. How about flat repairs? – It is inevitable that you will get a flat tire at some point & fixing a flat with a Mid-Drive is no different than fixing a flat without a Power Assist. It becomes quite a bit more complicated if your flat is on your trike’s back wheel. How about not having to have the added expense of having your motor built & trued into a new rim? Keep your original gears, wheels, shifters & tires so installation is far easier.

    Center of Gravity – Before you buy ANY system compare the weight of your Direct Drive, Geared or Mid-Drive Motor. Be sure to include the weight of all your components including the battery. You will find that the same size Direct Drive Motor with Regen built in is the heaviest with the least amount of torque & a Mid Drive can weigh as little as 6-8 lbs. with fqr more torque. This is hardly the ‘Disaster’ of adding weight out the front of your Boom that this article alludes to. I would be more concerned about adding a 15 lb. battery over top of a 26 inch back wheel that already had a 12 lb. motor built into it. Watch your trike try & dump you out on the first high speed turn or off camber corner you encounter because all your weight is now over your single back wheel.

    My advice would be to buy a hub motor if you want high speed but be aware of how it affects your handling & braking. Buy a Mid Drive if you want a simple to own & maintain system that gives you enough boost to climb hills. They both have their place in the Trike World & it’s great that we have choices.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.