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[enaef]

Hi everybody

As mentioned elsewhere, I am learning to ride on  SR/F. I have never ridden a combustion engine and don't know exactly how strong the engine brakes are there.

I'm interested in how much regeneration would have to be adjusted on the SR/F, so that it is about the same as the engine brake of a combustion engine.

I've heard that enginge brakes are different on different combustion engines. Nonetheless ...

[Crissa]

Every engine will give you a different amount of engine braking, and differently in each gear to speed combination.

Regeneration gives you a consistent amount at all times.

Just use it.  Turn it down if you find it too much, turn it up if you find it too little.  Different modes (rain, eco, sport) have differing amounts pre-programmed in from least to most.

I've been using 60% on my S, which doesn't answer your question, but it does sit between my Mazda 3 (which has very little engine braking) and my first car, a Honda Civic (which could be very severe).

-Crissa

[TheRan]

If you're actually trying to set it up to be like a combustion engine I wouldn't bother, just set it at what feels most comfortable for you. Just like trying to set the torque limit to emulate a certain bike there's not really any practical reason to do so and it doesn't really work, while a combustion engine's output (and engine braking) varies over the rpm range and depending on what gear you're in a single speed electric bike is going to be more consistent and you'll have maximum torque and engine braking available to you most of the time.

Of course if you're interested just out of curiosity then I'd also like to hear input from anyone else. I think we have measurements for the actual torque value achieved by using regen (something like 100% regen being 10% of maximum forward torque), I don't know if there are measurements available of the engine braking of combustion engines (or even a way to measure it).

Perhaps there's a formula to calculate it but it wouldn't be simple. You'd need to know the force required to compress the air in the cylinder (so displacement and compression ratio) and then turn that into torque at the crankshaft (I think you'd need to know the stroke length for that), then multiply that by the gearing in the drivetrain (and do the same for the electric bike to get a fair comparison).

[enaef]

Well, I need to explain why I'm asking this question.

Except for a short try I've always used Eco-Mode as I'm learning to ride the motorcycle.
In Eco-Mode regeneration is at 100% for cruising and braking. I feel quite comfortable with that.

However, the first time I had a passenger with me, in order to practice for my licence test, he told me that I used the brakes in turnes which I shouldn't at my licence thest ride.
I did not use any brake but used only regeneration.

I know/knew from the beginning that it is not allowed to use brakes IN turns but one has to use them before and then go through the turn in a steady state to the point of acceleration again.
I never thought of regeneration as a form of rear brake, what it physically actually is ...

So I would like to learn to ride the SR/F in this respect like a comparable bike with combustion engine in a way that the examiner won't complain about breaking in turns ...

I think it helps me to set the regeneration to a degree which forces me to use the real brakes before the turning point. Although it never fealt dangerous/insecure using regeneration IN the turn I just want to avoid everything that could cause me failing the test ...

[Richard230]

You can cut the regeneration drag to zero by using the custom setting on your bike.  I have my Zero set up like that and it will coast with the throttle shut. I also have it set so that it gives 100% regeneration drag when the brake is manually used, in order to help braking and reduce pad wear a bit.

Regarding any comparison with a gas-powered motorcycle, I would say that 100% regen is equal to most of my motorcycles going downhill in third gear with the throttle shut. With regen set at zero, the bike will seem similar to a gas-powered motorcycle coasting in neutral, or with the clutch pulled in.  Setting the custom option to between 0 and 100% on the slider can give you anything in between.

[Crissa]

Regeneration can come from either braking or off-throttle and for the test they'll be looking at the braking/brake light.

Except when you're supposed to be doing a counter-steer initiated turn, dragging the brake is considered good behavior.  But the range rules may require you to 'not cover' the front brake while doing maneuvers (except specific braking maneuvers).  I don't know any that will ding you for covering the rear.  The rear brake makes many slow speed maneuvers easier.

-Crissa

[TheRan]

Similar to what Crissa said, engine braking (or in this case a bit of coast regen) can help with stability in slow speed turns so setting the bike to 0% regen probably won't help. If you learn to ride like that once you hop on the gas bike it will want to tip in a lot more when you roll off the throttle and you'll be at a higher risk of dropping it.

[MrBlc]

Weird.. In my country, braking while turning is part of the requirement to get the license. Also, what others have stated, engine braking would also happen if you let throttle up. So.. Setting it to zero would be wrong as well.

IMHO I would rather have focused on learning where the zero point in the throttle is(where it neither accelerates or brakes), and taught myself to keep it there whenever i didn't need either throttle or regen. Doing so is a MUCH bigger benefit to you personally and gives you better control of the bike's behavior.

Good luck on the trials, and as long as you have a good instructor, practice makes perfect.

[Crissa]

Well, there's lots of turns to master; the slow-speed turn, where your use of brake and clutch is essential; the at-speed turn where you need to brake ahead of time to be at the right speed for entering the corner; and the straighten from a turn and brake emergency maneuver... And that's just the beginner ones.  If you brake at the wrong time in the latter two it's a fail.

-Crissa

[MrBlc]

In my country there's also the brake to stop while in turn, which is the one i was referring to..

[valnar]

I can't say what you should use for the test but I like my custom regen around 65%.  It may or may not be the best for range, but for city driving I like having the bike naturally slow down a bit before I make turns.  It really helps a lot.  If I need more, there is the brake.

[heroto]

Even 0% regen has some drag, I think related to the magnets in the motor. It's not like coasting on an ICE moto in neutral.

[Auriga]

Even 0% regen has some drag, I think related to the magnets in the motor. It's not like coasting on an ICE moto in neutral.

The SR/F with >13 firmware allows "true" 0% regen, and it seems pretty close to me. Older bikes not so much.

[enaef]

In the part of Switzerland where I live, the test is done at two different days:
1. manoeuvres (without passenger)
2. street ride, with the examiner as passenger, and only if one got a pass in the manoeuvres

I plan to use full regen for the manoeuvres. I don't think that will be a problem in the test.

My question aimed probably the most at the situation by crissa described at "the at-speed turn where you need to brake ahead of time to be at the right speed for entering the corner".
Yes, it is the at-speed turn, especially downhill, where you need to be slower in the turn than before and after. In this situation the examiners don't want to feel brakes being used. 100% regen in coasting feels definitively like using the rear brake in this situation. At least on the SR/F.

I also think, setting regen to 0% does not make sense. (I know how to set the regen settings).

I will try to find the zero point in the throttle, as suggested by MrBlc. At the moment I can't as the SR/F is with my dealer for a change of tires.
I wonder how that point feels exactly. Is it pure costing, like using the clutch on a combustion enginge?

Leaving the regen at 100% in coasting I fear that I might miss the 'zero throttle point' out of agitation in the test situation. Then the regen kicks in harshly. That's what my passenger felt riding with me through corners me using coasting-regen.

Another friend (not the passenger I had on the SR/F) owns a DSR Black Forest and he told me, that 100% regen on the SR/F, with which he did a test ride, was much more intense than on his DSR.

The last setting I did before bringing the SR/F in for the new tires was 43% regen each. It felt not bad, and downhill I certainly had to use the real brakes before turning in the corner, then trying to keep up the chosen speed during the corner.

I anyway plan to book a driving instructor whom I will ask about this. He will not be experienced with el. motorcycles. I hope he nonetheless will tell me if it feels ok or not in rather speedy downhill turns.

[Crissa]

It's more like being in gear in a lower-powered vehicle, where the engine is just keeping up with the vehicle's momentum.  There's a tiny spot where you're neither dragging nor boosting.

-Crissa