Abrubt Acceleration.....

[CSH]

Can the ebikes like (Magnum) be toned down when it comes to initial acceleration ?

I test rode one, and at the slightest start off, I popped a wheely !
As well as making a tight 360 degree slow turn around, it lurched me around that turn.

Can the control of bikes like this be Tamed ?

Craig

 

[harryS]

For tight maneuvers, you learn to ride with a finger wrapped around the brake lever. Usually, the motor cutoff switch in them will inhibit the motor before the brakes engage.

Other actions beyond that or in addition to that include shutting off the pedal assist before engaging in a tight maneuver or shutting off the controller completely .... depends on how your console works. To me, all of this is as normal as downshifting into low gear when coming to a stop on a regular bike, so one can start off again in a low gear.

Your wheelie must have occurred with the throttle? My 20" folder has much of my weight over the rear wheel and can wheelie if I'm leaning back and engage the throttle too fast at a stop, but it's only a little jump. I just have to roll it on slowly.

This is one problem with cadence systems. Unless they included a really low power PAS 1, most PAS 1 levels will boost you over 10 mph quick, so it can be hard to amble along with friends on regular bikes (unless I cut power).




I

 

[Deleted member 4210]

You didn't say which model, but the Metro, Metro+, Cruiser, Premium, have 3 modes in the second level menu screen, that allows some softening of the acceleration for all levels.

Lowest level is Eco mode, which will give the longest battery range as well.

Aventon is coming out with software and plug-in dongle, for changing that acceleration on their ebikes, that will allow the dealer to reduce acceleration and speed in the field for each level of assist. This is for their Pace models, which many riders claim are as fast as the Magnums. It'll be a bit before that happens so anyone with an Aventon, don't ask your dealer for it just yet.

Maybe Magnum will eventually do the same ? (Hint, hint)

 

[rich c]

Don’t you lower assist level for low speed maneuvers? I use the assist levels like overdrive. One hand adjusting assist levels and the other hand shifting on my bikes. No direct experience on your model.

 

[Deleted member 4210]

Can the ebikes like (Magnum) be toned down when it comes to initial acceleration ?

I test rode one, and at the slightest start off, I popped a wheely !
As well as making a tight 360 degree slow turn around, it lurched me around that turn.

Can the control of bikes like this be Tamed ?

Craig

For safety and quality check, I test ride every single Magnum that comes through my shop,and never came close to pulling a wheely.

 

[AHicks]

People that have ridden my bikes are sometimes startled that first time they are exposed to even relatively low amounts of assist. Just a couple minutes later there's this big grin that sort of takes over....

I can't even imagine having to turn off the bike's controller to maneuver at low speeds.

Regarding PAS levels, the bikes I'm used to (direct drive rear hubs) will go 10mph in PAS 1, but you're going to have to be helping out to get it to go that fast. Depending on how fast you pedal, you can go so slow you'll have difficulty maintaining your balance. Your speed is directly related to how fast you pedal.

 

[harryS]

I can't even imagine having to turn off the bike's controller to maneuver at low speeds.

This is the 810LED display, used on a quite a few ebikes. It came with my first kit conversion
that I did in 2015,and also on the $700 Ecoctric fatbike I bought earllier this year.

It has three PAS modes and if powered up, PAS 1 is enabled. To get zero PAS, the display
has to be switched off. Press the red button on top left. It's just one button, same as pressing
the arrow button on an LCD 3 to get PAS 0. Well, that's how the simple folks live.

 

[AHicks]

Are we talking about a hub drive, or a mid drive in granny gear? If mid drive in granny gear, I guess I could get the bike might surge ahead to a walking speed. Hub drives don't do that. Nothing I've ridden anyway.

 

[harryS]

CSH just told us what happened to him. A u-turn at 4 mph using the pedals, and with a cadence sensor., the bike will try to accelerate to at least 8 mph with 1/4 turn of pedals if you have power on. A lot of stuff that you and I are used to, a newbie has to learn.

 

[AHicks]

My point was/is not all bikes do that. Trying to better understand why this one did that, and with that information, if anything might be able to be done to fix it.

I'm not going to assume that kind of behavior from a bike is normal.... (wheelies or accelerating to 8mph with 1/4 turn of the pedals). Sorry, not buying it. If a newbie needs to learn anything from that experience, it's that bike is messed up!

 

[harryS]

You got me. I exaggerate. It jerks like it will go to 8 mph, but it really doesn't. It will if you continue pedaling. As you have a KT controller and LCD3, you may have occasionally rotated the pedals to facilitate a flying mount. and had the motor jerk as the cadence sensor triggered. I'm in the habit of doing that in PAS 0.



,

 

[Rodolfo]

Is this a veiled sales pitch? I want an unTamed bike! At least to bronc-ride it for my 8 seconds...

I agree it's a matter of experience, as with most of riding and life. I still remember the big Grin that first-pedal lunge produced on my first electric test ride -it was all I needed then!

 

[GregGritton]

Can the ebikes like (Magnum) be toned down when it comes to initial acceleration ?

I test rode one, and at the slightest start off, I popped a wheely !

(I posted this in the Aventon forum, but it seems relevant here.)

There seem to be various types of Cadence sensing controllers
- Constant voltage - This drives a constant voltage to the the motor, based on the assist level, with the current limited by the controller. At low speed you hit the controller current limit regardless of the assist level. Thus, you get a hard shove even at low levels. The Aventon and Magnum Metro, among other bikes, has this type .
- Constant power - The controller tries to feed the motor a constant power based on the assistance level. Thus,
at low assist levels you get a gentle push. Rad Power Bikes has this type on the Rad City. I much prefer it to constant voltage. You will still get higher torque at low speeds than at higher seeds but the drop-off isn't too steep.
- Constant torque - The torque stays constant based on the assist level until you are going fast enough to hit max power. I don't know of any bikes that have this, but there may be some.

If you are technically inclined, you can see the torque curves for constant voltage (the default) or constant torque (if you select a custom controller with constant torque) at https://www.ebikes.ca/tools/simulator.html. Changing the throttle setting is the equivalent of setting the PAS (pedal assist) level.

Finally, torque sensing bikes work differently, sensing your pedal torque and multiplying that power, giving a fairly natural feeling.

 

[AHicks]

So that information fresh in memory, and Mike's first note above regarding the 3 different power levels/modes, it sounds like Craig's question would depend on what "mode" the bike was in when he rode it, and possibly, why the sales staff didn't explain that function to a potential customer - especially one that came away from a demo concerned about wheelies at low operating speeds!

 

[CSH]

Thank You..................

You have all been gracious in answering my question.

I should do you the service however, of refining my story.

1. My Wife & I are in our early 60's.

2. She, is of the utmost concern to Me, (safety wise).

3. My desire to Tone Down the lurchy-ness of a Hub driven bike like Magnum Metro, is mostly so that she is less likely to be caught off guard by the bike, and therefore not get pushed forward at a rate she may not have the built in Reflexes to react with (like us Boys do. Remember guys, we grew up trying to make Everything GO FASTER, MAKE IT SKID, POP A WHEELY ! )
I find that girls don't have those years of conditioning in their DNA, so to speak.

4. I rode Motor Cycles as I got older, and am fairly accustom to the potential acceleration at ones disposal.

5. For reference, the Wheely I spoke of in the original posting, was just that the Wheel came off the ground about 4 or 5 inchs, from a stand still start. I had no problem with that (although surprised), but again, to me it is how might that catch my Wife off guard.
Not to mention the lurchy-ness in a Slow U-Turn.

6. I do believe the "ECO Mode" solution (deeper in to the Display Settings) should help. Thank You.

7. And last of all.......... Both my Wife & I enjoy the exhilaration of Power, and (safe) Speed. We Just want the ability to control it.

As a kid, I remember the difference of a really good (but strong) Horse ride,
vs. a horse with a mind of it's own, that at a moments notice would BOLT !
Not so fun...............

Thanks for listening,

Craig

 

[AHicks]

Craig, I get it. A good portion of my riding is done with my wife who turned 70 this year. She likes riding, so if she did a wheelie it wouldn't spook her completely IF there were a good explanation, and a repeat could be avoided.

 

[ebikemom]

New ebikers are often startled by PAS (Pedal Assist System) at first, and this reaction seems stronger if folks are older or have slower reaction time. My dad, for example, prefers not to use PAS at all. He uses his throttle to get the level of assist he wants, completely predictably and completely under his control. His bike (something very cheap that he got online... Nakto??) has PAS, but he doesn't use it.

Ebikes with throttles do, from what I've seen, have this "no PAS" option. And, there are also throttle only (no PAS option) ebikes out there, and their price tags are lower than the same maker's models with PAS (see, for example, the Pedego Comfort Cruiser).

Happy Shopping!

 

[vincent]

not all PAS respond like this, it also tends to be more a cadence bike issue than torque

every manufacturer is different but all of these cadence bike companies need to up their game
cadence bikes can be much more controlled if the controllers are programmed like that

imo at this stage of the game it is ridiculous these bikes still act like this

this is the number one deciding factor when i look at any bike- how the pas responds
and have ruled out numerous companies in my searches for bikes on this one reason

 

[AHicks]

What happened here is that the bike's controls were not properly explained to Craig. When he got on it the controls were set for max available power (likely for somebody wanting to see how fast it would go) - resulting in some lurching from a stop/at low speeds. The bike is equipped with 2 lower power ranges, each with progressivley milder "tuning". The use of the mildest setting very likely would have eliminated the issue Craig had. -Al

 

[Rodolfo]

Craig, my bike is a torque pedal-assist, with throttle, and my assist is quite gradual, at any power level, and doesn't engage, in any event, until maybe a half a pedal stroke. I'd welcome a significantly greater thrust, especially in a left-turn lane ahead of traffic , though I now have 6 years of pedal-assist riding, and I'm still gaining experience. By the way, although I've been riding 2-wheelers since my 4th Xmas, I didn't get my first and only ebike until I was 65. Enjoy your patient shopping and learning, and your eventual choice. Congrats to you and your wife for being able to ride in your 60s -we're fortunate, and safe riding to you both.