YAMAHA EASY.. Old pedelec ebike but the 24v mid drive unit has potential

[Beach Thorncombe]

I was thrown a curved ball this week when I tracked down a mid drive pedelec at a local auction. (I acquired it for under £40).

The machine is a Yamaha Easy, (the basic one, not the Easy Super) and it once ran from a, now missing, 24v nimh 6ah battery. (That’s no problem because I make my own BMS protected lithium battery packs from 18650 cells myself).

The mid drive is old. (2003), the system is 24v, (different than all my other machines), and the battery tech is now out of date BUT none of those facts matter at the moment. All that matters, at present, is firing up the mid drive to see if it runs.

So … a few questions

1. Is the Yamaha Easy also known as a part, product or model number?

2. Can anyone provide the Yamaha Easy’s mid drive ref / unit number and spec / wattage?

3. Can anyone provide correct wiring detail for Yamaha Easy battery case in relation to the 3 pin interface it attaches to on the bike? (It looks similar to an early Giant battery pack).

Viewed from the (missing) keybarrel entry hole, (on the left side of the machine), I can peer within and see that the 1st pin has a heavy duty RED wire attached. The 2nd pin, (in the middle), has a heavy duty black wire attached and the third pin has a thinner pinkish, (possibly faded red) wire attached.

4. Can anyone confirm pin arrangement / voltages in relation to above? Does anyone know what voltage goes to which pin? Or what the thinner pinkish cable serves? (The sensor? The PAS?)

5. Can anyone furnish me with any other technical detail?

Thanks,

Beach

 

[LeighPing]

Some info, from an older post, here. Good luck.

http://www.pedelecs.co.uk/forum/threads/yamaha-easy.10338/

 

[Beach Thorncombe]

Thanks LeighPing. The link looks useful, particularly with regards to the diagrams. I may have a challenge converting the text but at least I have something to go.

Thank you for your prompt response.

 

[Beach Thorncombe]

And ... of course ... a grateful acknowledgment to Flecc for providing the original link to the useful PDF document it illuminates.

 

[LeighPing]

And ... of course ... a grateful acknowledgment to Flecc for providing the original link to the useful PDF document it illuminates.

There's a few here that speak French. I'm sure they'll help you out.

 

[Beach Thorncombe]

Mmmmh. Trouble is, as Flecc points out, while the mid drive motor may be similar, the actual bike being referred to in the PDF is a different model.

If I were to focus on the most important piece of information I wish to uncover, it would be the following.

Do true pedelec* cycles with battery packs of the three pin interface variety share some common, generic wiring arrangement?

I ask because unlike a throttle based ebike, a pedelec machine assists and compliments a rider once the rider starts pedalling thus, I'm assuming, (guessing), that the thinner pinkish wire connected to the furthest of the three pins I outlined in text, (above), MUST carry a message similar to a sensor informing a regular throttle based machine that it is 'on the move'.

The Yamaha Easy has an OFF, ON and ECO switch which, presumably, manages (or informs)) the PAS. (Power Assist System) through such settings.

Is there some example of a typical PAS 3 pinned / 3 wired setup somewhere via a link online? ... or, (if there is some sort of generic setup), can anyone here enlighten me on the possible wiring arrangement I would expect to see?

Having reduced my own questions to this possible line of enquiry, I'll look online myself but if you can help, please feel free to add your thoughts here.

 

[D8ve]

Beach the thin wire is unlikely to control the drive. The battery voltage feeds control and motor via the control unit. The wire may be supply for switching on off that's common practice.
But this is guess work from me.

 

[Beach Thorncombe]

Google translate is pretty good. Reading the French notes, I've just established the similar bike described in the PDF has a superior torque sensor rather than a basic movement sensor.

Flecc. May I ask? Referring to earlier posts specifically discussing the Yamaha Easy elsewhere on this site, you seem to have some familiarity with it.

Can you recall if it too has a torque sensor?

I ask because I'm anticipating that my earlier request for 'generic wiring' info might be innapropriate ... if there are at least TWO possible options due to two differing sensor types having to to be considered.

 

[Beach Thorncombe]

Hi D8ve, Long time no see!

OK. So the little rectangular control box on the handlebars, (OFF, ON, ECO), plays a minor role? Simply taking power from the thin wire to either switch on, (or prepare), the motor, (Regular) or switch on in ECO mode? ... possibly?)

And then other circuitry or some mechanical process (currently unknown or invisible to me), reacts to the torque sensor, distributing power accordingly?

I've never come across one of them before but they seem very clever / very efficient in, seemingly, "knowing" how much force a rider is exerting ... and either matching that force (ECO) or doubling / tripling the riders own input , (Regular ON mode).

I know that Kalkhoffs, (and others), can have several individual settings but I'm happy to just get my head around the two on the Yamaha Easy for now.

Just chatting now as an aside but ... do mid drive units normally have what we might describe as regular 'Controllers" ie a controller described as, (in this instance), "a 24v 200 watt (or whatever) controller unit?"

Or does the mid drive unit present us with an entirely different means of controlling it?

 

[Beach Thorncombe]

Here is the drive unit ... and here's an intriguing thought ...

The unit looks very bespoked ... and the actual bike has a weird frame, (certainly not like a regular familiar frame) SO ... until I were to dismantle it, I'm of the opinion that it is unlikely that the unit could be removed and installed on some newer, more traditional frame ... though I might be wrong and, perhaps, by rotating it and making use of some, currently, unused spare threaded lugs, (covered with rubber bungs at present), it might just make itself a portable mid drive I could use elsewhere.

BELOW are the three lugs or pins or blades ...

Is this setup an industry standard ... or was it ... in the days of Nimh batteries?

And here, (below), we can peek inside the empty key barrel assembly and spot the heavy duty black and red cables in the foreground ... and the other thinner cable beyond. (Unless I can crack / resolve / complete this simple looking puzzle, I can't easily test the motor).

Frustrating, eh? All I need to know, (based on building a replacement 24v lithium battery), is what voltage goes to what pin?

I read elsewhere online that, possibly, the red wire takes + 24v, the black takes the earth / negative - and the little wire takes 12v, (The arrangement sounds similar to what D8ve stated re delivering voltage to the controller / box), but the info was written so ambiguously, I wouldn't dare try that unless I got some consensus here.

OK. She's not a looker, (below) but ... allegedly, while a basic workhorse running on only 24v, she can climb walls with that efficient, clever, mid drive unit. (I say clever but that is only true if we assume she has got a torque sensor). In any event, she only cost me £35 at auction.

 

[D8ve]

Simply the little switch box sends a signal back to the control unit in/around the motor. Turning the cranks is sensed and the pressure applied activates the motor in proportion to how hard you press on the pedal.
More details of the way it's done on flecc's informative articles.

 

[Deleted member 4366]

Just follow the pink wire to see where it goes! Drag the motor controller out and show all the wires. We should be able to decode what's what. Follow the two thick battery wire, which go directly to the motor controller.

 

[Beach Thorncombe]

I haven't had the pleasure of viewing Flecc's articles yet. (Didn't realise there was such a resource here ... but I'll be all over it later today!)

 

[Beach Thorncombe]

Hi d8veh, Glad to have your input.

OK. Tomorrow, I'll dissect the patient and report back!!!

 

[Beach Thorncombe]

Night all. Thanks for being here.

 

[Beach Thorncombe]

Well. I've discovered a plate that tells me what model number the Yamaha Easy is. It is an X99R. (It was hiding in plain sight on a label in the lower vee of the frame).

 

[Beach Thorncombe]

 

[Beach Thorncombe]

The plastic casing or 'pot', (probably hiding some electronics), simply refuses to budge, lift off or decant from the top / side of the motor though. :-(

There are slots indicating some kind of wedge or lever action might release it but ... No ... It just won't move.

VERY frustrating. Disheartening ...

 

[Beach Thorncombe]

One slot can be seen, circled in red, but even by using 'the law of the lever', it refuses to facilitate the removal of the plastic cover.

I think the bike is a very early, maybe even the earliest, example of a Yamaha mid drive unit on a pedelec so I mustn't butcher or damage the thing.

 

[Beach Thorncombe]

Let me just drop this link here for later. http://www.pedelecs.co.uk/forum/threads/yamaha-easy.109/ (Flecc makes some interesting comparisons regarding the Yamaha Easy and other, similar, bikes).