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New Epure Owner


trapezeartist
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On 10/28/2021 at 9:02 AM, dgshannon said:

On the surface, sounds good, when you only think of heading down hills. In practice, throttle closure occurs in too many different situations other than downhill.

With a gas engine, rolling off the throttle is followed by continued flywheel engine inertia. So, the Electric Motion, as it stands, is already a bit of a shock to new riders as rolling off the throttle does not have that same inertia, and forward motion ceases much faster. If you add regenerative braking to the throttle action, that would even be more severe.

Think about heading uphill on a gas engine bike. You always roll off a bit and let flywheel inertia carry you over the crest. With a stock Electric Motion, you quickly learn that you better not do that. Even worse if you tied regen braking to throttle closure.

On a downhill run a gas engine provides engine braking, as the rear wheel tries to drive the engine at a faster RPM than it wants to go. In other situations, the gas engine at is still providing a bit of forward momentum while at idle. That characteristic is what the new "tickover" feature on the 2022 EM is trying to imitate. What you are suggesting is the opposite in that closing the throttle would not only stop producing power altogether, but even start resisting forward motion. I don't think that in the end it would be a desired characteristic.

If regen braking were to be linked to any trigger other than its own separate switch, it might work by linking to the front brake lever. It may be a total bust, but would be an interesting experiment. The same type of front brake switch that triggers a brake light could be used to trigger regen. Sounds plausible that if you want the front brake on you might want the rear wheel to experience regen drag as well.

Alternatively, it might well work if the switch was on the rear brake peddle. If it were setup such that the peddle in its full up position closed the switch and turned off regen, the the very moment you pressed the peddle down (even before starting to engage the rear brake) the regen would kick in. Further pressing down would add the physical brake to the regen.

It seems the FRB when asserted disables the throttle. I guess that makes sense, can't simultaneously use the motor as a generator and a motor. I no longer think having FRB assert with either brake is a good idea. Can't use the brakes and spin up the flywheel.

I am also wondering if the FRB is a good idea at all from a failure mode aspect. If the mechanical switch fails open, no big deal, just lose the ability to assert FRB. If the mechanical switch fails closed then lose the motor. Even at my low level of riding I often am on rock where I would dislike losing the motor. I'm curious if anyone knows if the factory EM FRB switch is a single fail component, or a multiple fail component. Single fail meaning only one component has to fail to inadvertently assert FRB, multiple meaning two or more components have to fail to inadvertently assert FRB. My homebrew switch is single fail and is coming off the bike today. 

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The FRB is a ‘Normally Open’ switch/button.  

 I suppose it could somehow fail close- but I don’t think very likely.  More likely would be wires getting chaffed due to improper routing/covers and shorting across- activating the FRB.

  I use  a very high quality switch (not the EM one) and it has been flawless.  Another great feature is if you have to stop on a really steep hill (either someone stopped ahead, tree down or just mess up) pressing the FRB with also work in reverse. So it acts like a rear brake- pretty effectively at a stop.

  I have it located such that is it highly unlikely I would ever hit the button unless I want to.  (I never have yet)-  it will immediately ‘turn off’ the power and start the regen.  If you hit it by accident with throttle on- then take finger off button, it will immediately give what ever power the throttle is set to.  THAT could be an eye opener.

  But I’ve only done that when fooling around to see how the button reacts and how the bike responds.

I don’t do competitions any more, but I would still use the FRB on a steep downhill, since I can then put my feet where I want, hold the button down  for excellent ‘braking’ and just feed in more front brake if needed, or slip the clutch if I want a bit less.

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On 11/1/2021 at 3:25 PM, lotus54 said:

Another great feature is if you have to stop on a really steep hill (either someone stopped ahead, tree down or just mess up) pressing the FRB with also work in reverse. So it acts like a rear brake- pretty effectively at a stop.

That's a really interesting feature I hadn't even considered. Normally if you stop on a steep uphill with nowhere to get your left foot down, it's really awkward. I've done it so many times. In future I'll use the FRB.

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  • 8 months later...
On 11/1/2021 at 5:25 AM, lotus54 said:

I use  a very high quality switch (not the EM one) and it has been flawless.  Another great feature is if you have to stop on a really steep hill (either someone stopped ahead, tree down or just mess up) pressing the FRB with also work in reverse. So it acts like a rear brake- pretty effectively at a stop.

i put a switch on so i can do the same... lock up the rear tire if you dont make a hill and need to drag back down.... super sketchy with the rear wheel freeheeling...

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  • 2 weeks later...

A buddy just bought one of these bikes and I do find the button odd for RB.  I have a 2018 Triumph tiger with an electronic throttle.  I believe it is a hall effect sensor type device but it has a spring loaded switch that is triggered when pushing the throttle closed.  On that bike, it is used to cancel cruise control but it would seem ideal to trigger regenerative braking on the EM bikes.  Is anything like that available?   The Domino throttle does have an unused switch but it may be to ensure no no movement due to electronic noise with throttle closed.  Maybe like a kill switch.  It is not clear to me.    

D Throttle.png

Edited by mcman56
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47 minutes ago, mcman56 said:

I believe it is a hall effect sensor type device but it has a spring loaded switch that is triggered when pushing the throttle closed.  On that bike, it is used to cancel cruise control but it would seem ideal to trigger regenerative braking on the EM bikes.  Is anything like that available?   The Domino throttle does have an unused switch but it may be to ensure no no movement due to electronic noise with throttle closed.  Maybe like a kill switch.  It is not clear to me.    

Both the old Magura, and the new Domino, throttle are 0-5k Ohm potentiometer units. No Hall Effect on these.

I just ordered, and received, a Domino throttle (not from EM) and I am waiting on the necessary connectors to arrive, before I install it. I am going to use it to replace the Magura on my 2021 Race.

The Domino does have two extra wires for the micro switch. If you get the Domino from EM themselves, I have not clue what, if anything, they are doing with the micro switch. To your point, I have likewise considered tying the micro-switch into the FRB connector, such that throttle closed would trigger regenerative braking. However, not that I have the throttle in hand, there is no play, or gap, between throttle off and switch closed. In the end, I don't think that using it for regenerative braking would be wise. When negotiating obstacles in trials, crossing logs, climbing hills, etc. that last thing you would want is the sudden trigger of extreme braking when you closed the throttle. It would be great if the transition from throttle closed, to micro-switch closed, had a minor mechanical stop. In other words, you would have to intentionally trigger it by closing the throttle a bit further than natural stop. But alas, that is not the case.

I have found a handlebar mounted thumb button that I think will do the trick. When mounted in reverse, the offset of the design should place the button in a position that your clutch finger can easily reach and press it. To me, that seems like the most natural way to trigger regenerative braking. Certainly not a thumb button, or the seemingly awkward second lever, above the clutch, the EM is using. 

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I use a lever under the clutch lever for my FRB. For me, it's ideal. John Uyehara in Hawaii makes them. I think it is basically a pushbike lever or possibly something for a small quad, that he mounts a magnetic switch in and then adds a wire with the correct connector. I thought about buying a batch from him for re-selling in the UK, but never did anything about it.

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