Utility Cycling Technology: Regen For Bicycles

Wednesday, November 27, 2019

Regen For Bicycles

EP-OSET-HB3616 For 16.0 Racing (pre 2015).
Alloy with OSET logo with double disc bracket. 36H

https://osetbikes.com/gb/parts/
pre-2015-parts/hubs/rear-
hub-for-16-0-racing-pre-2015/

You will never get back the power it takes to climb a hill. And bicycles are too lightweight to generate enough to earn your money back. However, if you live on steep terrain and haul heavy total combined weight like I do, it may be worth trying out. But you may need to mount the motor in a different place, or at least turn it around to drive the left side. Make sure your controller is made for “regeneration” before you do anything. And make sure it will work in reverse [left side].

There are too many free-wheeling gears on the crank to let you drive the motor through them. So you will need a new drive wheel with an extra wide hub that will give you more room for a drive chain that will clear the tire, on the left side. This hub will need to hold a disk brake rotor and a large sprocket on the left side and a single speed free wheel cassette on the right side and it may not have thread for a free wheel, only bolt holes for a sprocket on the right side [for pedaling, and you will need to experiment to find the right size sprocket for it].

Hope Fatsno Pro 4 Rear Hub 32H 197mm x 12mm

These hubs are hard to find. Or you could do what most people do and have a double drive on the right side. You need two single speed free-wheels on the right side, but the one for the motor will have to be welded so it will NOT freewheel while the other one will be freewheeling to keep from driving the cranks when going down a hill. And the one for the motor may need to have left side threads so it will not come unscrewed from the freewheel mounting threads. You need to research this yourself.

If you can't get a hub that will hold a freewheel on the right side with sprocket and rotor on the left, use a crank that is rigged with a freewheel bearing. Available in mid-drive motor kits. It is cheaper to buy a kit with the planetary gears and the freewheeling crank together any how.

Then once you have your single speed motor drive set up and tested to adjust the size of sprocket used, you may want a two-speed gear-box. This is very difficult because it would need to be built without freewheels.

fixed gear cassette

https://lmxbikes.com/en/spare-parts
/94-lmx-170mm-double-
freewheel-rear-hub.html

For 2.25 inch tires 150mm to 170mm hub but for a 2 inch wide tire you maybe able to get by with a 135mm wide hub. I am going to use the widest hub I can get for my next bike, just to try to keep the chain reasonably clean. And I want to be able to use 2.5” to 2.75inch tires. These need a steel frame that can be stretched wider. Don't use those 4” tires that are absurdly popular now. They are too thin for hauling 450 lbs or more on two wheels; 4 ply motorcycle tires are the thing to use for a real cargo bike. If you want to believe those positive lies the industry puts out, that is your problem, don't tell me about it.]

There is another problem with regeneration of power going to the battery. Normal charge rates need to be very low like 3 to 5 watts.

If the regen operation produces much more than that you could damage your battery. I just don't see any reason to do this on a bicycle no matter how heavy it is.

A motor must be more complex to integrate regenerative braking.
Electronics must account for regenerative braking, making it more complex.
Manufacturing is more intensive and components cost more.
The price to the consumer will be higher unless other factors can help with the resulting cost.