Is regenerative braking really worth anything?

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John in CR   100 GW

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Re: Is regenerative braking really worth anything?

Post by John in CR » Sep 27 2020 3:16am

Balmorhea wrote:
Sep 27 2020 12:53am
John in CR wrote:
Sep 26 2020 7:39pm
Balmorhea wrote:
Sep 26 2020 1:37am
But when you spin the axle and it costs more to fix it than to get another motor, that feels not so good.

Reversing torque does that to pedals, to cranks, and to the axle nuts of hub motors. Using a freewheel rather than a fixed gear prevents it for pedals and cranks, and using forward-only drive prevents it for hub motors.
If your axle budges at all (loosening axle nuts, clicking when you hit regen, etc.) then you don't have proper torque arms and/or the flat area of the axle isn't of sufficient design.
You'd think so. But cranks mounted on square tapers don't "budge", and neither do pedals that have been tightened upon mounting. But both can move enough under reversing torque to back the fasteners off, and then everything goes sideways.

The remedy, if you must use fixed gearing, is to check and tighten these things often. I'm willing to bet that not one in ten people running regen braking do that.

You can prevent the problem by using clamping dropouts. I'm willing to bet that not one in a hundred people using regen do that.
It's not a plane where a preflight checklist is a mandatory safety precaution. You are obviously the 1 in 100 that likes doing all that crap on bicycles. The rest of us want the convenience of a car, not fiddling with brakes all the time, checking that nuts are tight etc. The way you advise people regarding ebikes is the polar opposite the way I do, whether in person or online, and mine is to build it right the first time which without fail includes to properly attach the motor axle to the bike, so they can enjoy absolute reliability.

Balmorhea   100 kW

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Re: Is regenerative braking really worth anything?

Post by Balmorhea » Sep 27 2020 11:38am

John in CR wrote:
Sep 27 2020 3:16am
Balmorhea wrote:
Sep 27 2020 12:53am
But cranks mounted on square tapers don't "budge", and neither do pedals that have been tightened upon mounting. But both can move enough under reversing torque to back the fasteners off, and then everything goes sideways.

The remedy, if you must use fixed gearing, is to check and tighten these things often. I'm willing to bet that not one in ten people running regen braking do that.

You can prevent the problem by using clamping dropouts. I'm willing to bet that not one in a hundred people using regen do that.
It's not a plane where a preflight checklist is a mandatory safety precaution. You are obviously the 1 in 100 that likes doing all that crap on bicycles. The rest of us want the convenience of a car, not fiddling with brakes all the time, checking that nuts are tight etc.
You misunderstand. The checking I do all the time is on other people's bikes, at work.

I don't do those checks often on my own bikes, because I don't have to. Because I don't use fixed gearing or regen braking. I use regular bike frames can go back to being pedal bikes any time, like most of us do.

The easiest way to avoid predictable problems isn't welding stuff onto your frame. It's not doing the thing that brings the problems to begin with.
___________
Finish Reconstruction.

John in CR   100 GW

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Posts: 14662
Joined: May 20 2008 12:58am
Location: Paradise

Re: Is regenerative braking really worth anything?

Post by John in CR » Sep 27 2020 11:58am

Balmorhea wrote:
Sep 27 2020 11:38am
John in CR wrote:
Sep 27 2020 3:16am
Balmorhea wrote:
Sep 27 2020 12:53am
But cranks mounted on square tapers don't "budge", and neither do pedals that have been tightened upon mounting. But both can move enough under reversing torque to back the fasteners off, and then everything goes sideways.

The remedy, if you must use fixed gearing, is to check and tighten these things often. I'm willing to bet that not one in ten people running regen braking do that.

You can prevent the problem by using clamping dropouts. I'm willing to bet that not one in a hundred people using regen do that.
It's not a plane where a preflight checklist is a mandatory safety precaution. You are obviously the 1 in 100 that likes doing all that crap on bicycles. The rest of us want the convenience of a car, not fiddling with brakes all the time, checking that nuts are tight etc.
You misunderstand. The checking I do all the time is on other people's bikes, at work.

I don't do those checks often on my own bikes, because I don't have to. Because I don't use fixed gearing or regen braking. I use regular bike frames can go back to being pedal bikes any time, like most of us do.

The easiest way to avoid predictable problems isn't welding stuff onto your frame. It's not doing the thing that brings the problems to begin with.
And because you're too lazy to build it properly and lack understanding of how motors work you end up with a less efficient, lower performance, shorter range, poorer handling, more dangerous ebike. That's fine since it's your bike to suffer riding. The problem comes into play when you litter the forum with incorrect information that reinforces all too common misconceptions.

Bigwheel   100 W

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Re: Is regenerative braking really worth anything?

Post by Bigwheel » Sep 27 2020 10:16pm

donaldallen3797 wrote:
Sep 26 2020 11:30pm
Bigwheel wrote:
Sep 13 2020 4:05pm
I use front hub motors on my drop bar bikes and find the regen feature to be only be outclassed by the cruise control feature. The red button on the left hood is a momentary switch and when I want to slow down it is the first thing I go to. I can fully utilize the front lever while holding it also for full stops. Also works well as a drag brake when I don't want to go too fast downhill and will keep me at around 30 or so nicely while modulating it. As mentioned this is great for saving on pad wear.

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If you don't think it would work for you then it is easy to leave off the program.
Hi , Can you tell me who's kit your using with cruise control please ? I have the Magic Pie Black Pie 1000 watt and the cruise is a must ...Just wondering who else sells them with cruise control ...
You can set up cruise control on just about any hub bike with a CA3 and compatible controller. I have a 9c and an AnyAxle, both 1000w. I use it with a throttle in place of PAS.

donn   10 kW

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Location: Seattle

Re: Is regenerative braking really worth anything?

Post by donn » Sep 28 2020 9:59am

If for whatever reason you don't want to run e-brake and throttle controls through a Cycle Analyst computer, cruise control appears to be fairly common in run of the mill controllers, with the KH6xx infineon circuitry. Since controllers would mostly be Chinaware, it seems you will usually find them presented with no information at all about what's inside, but if there's a "wiring diagram", that will tell the tale - it should come with a pair of wires to enable cruise control (depending on whether circuit is closed or not.)

It's an excellent feature, for a controller with voltage throttle.

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