New Panasonic Unit Information

[flecc]

Emmanuel, a French Pedelec enthusiast, has started a website showing photos of his stripped down new generation Panasonic unit, but he had no access to an old one. We've therefore started a collaboration enabling him to reproduce my old Panasonic unit pages in French, and in return I've been able to use his photos in my website for a new article on the latest Panasonic unit.

In the article I show the insides of the new unit with it's differences from the old one described, both physical and operational, and I've appended information on the differences in the current high speed "S" units. Access is normally from the "Technical" page on my Lafree/Panasonic website, but here is the direct link to the article:

The New Panasonic Unit

where you'll also find a link to Emmanuel's website.

Here are my other website articles on the Panasonic units:

Old Unit details and repairs

Old Unit switch repairs

How the Panasonic crank drive systems work
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[tillson]

Thanks for taking the trouble to compile the information for us flecc. I found it very interesting.

Initially, I was a bit concerned about the use of a nylon gear and possible premature wear issues. But further in the article I was reassured to read about the expected longevity of this type of arrangement, based on experiences with hub motors.

Also I was interested to see that the voltage reduction for the lighting is done on the main circuit board. I have read on here that the output is a series of high voltage spikes which give a mean value of 6v when used with a filament type bulb. Because of this arrangement it isn't possible to upgrade the lights to LED type. I was speaking to Simon at 50 Cycles the other day and he tells me the Derby Cycles have now modified the lighting output with a separate circuit board which enable LED lights to be utilised. Unfortunately, Derby Cycles haven't been very forthcoming with information about the modified lighting output.

Thanks again for the article though.

 

[flecc]

Thanks Tillson. The lighting circuit conforms to Panasonic's policy of keeping everything together at the unit, except the handlebar control unit of course, and it does use the high frequency pulse method to produce an average 6 volts. Of course that's only suitable for tungsten filament bulbs.

Derby Cycles might be incorporating their solution inside the headlamp, working in conjunction with a lights supplier, and I can only think it's a full wave rectifier and smoothing circuit to turn the motor unit's lighting output into DC, removing the peaks that could damage LEDs.

I'd guessed the new unit used nylon gearing the moment I started testing the Agattu in 2007, since it was the only way that the noise level would have been reduced so much, so it didn't come as a surprise to me. The comparison with the nylon gears in hub motors isn't precise since they have spur gears while the Panasonic unit uses helical teeth which are subject to lateral sliding wear. The gear wheel is so much larger though that I cannot foresee it giving trouble.
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[JamesC]

Very helpful - many thanks

James

 

[Fecn]

Thanks for taking the time and putting in all the effort to write that lot - It's great to finally see the inside of one of the newer panasonic units. I was waiting until my warranty runs out (13 months left) before I took the screws out of my one for a look, but I guess you've saved me the effort now

Good to finally find out what the difference is with the s-class unit, and how simply replicated it could be. I wonder if the details on the programming interface are available anywhere... Thanks Flecc and Emmanuel.

 

[flecc]

In the early days of the Giant Lafree some dealers had a facility to adjust the power level, but the range of adjustment was small. With time Giant seemed to abandon that provision though.

Panasonic have always tended to be very secretive where consumer information on the unit is concerned, only occasionally releasing marketing information openly. That's probably due to their insistence that repair is only by replacement, leading to a "don't touch" attitude.
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[flecc]

I've now added a new page to my website as the index page for all my Panasonic items, new and old. It can be accessed from my Lafree website via a button, but is now also able to operate as a stand alone website for support on the new and old Panasonic crank drive units on this link:

Panasonic Motor Units

I've also added the details on the chain idler adjustment as a link from the maintenance and repairs section of the new unit page, but here it is direct:

chain idler adjustment
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[JamesC]

I've also added the details on the chain idler adjustment as a link from the maintenance and repairs section of the new unit page, but here it is direct:

chain idler adjustment
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Thanks again Flecc.

A useful tip regarding the tension arm that carries the chain idler wheel on the new panasonic unit.

The tesnion arm pivots around the shoulder bolt that passes through the alloy casing, secured by a nut on the backside of the casing.

The total length of the shoulder on the bolt is a fraction short for the overall depth of the fabricated arm plus the depth of the coil spring behind.

As a result, the arm does not always pivot freely, regardless of liberal use of grease.

By adding one flat washer between the shoulder and the alloy casing, the length of the shoulder is increased, and the arm moves freely throughout its range. The small discrepancy in sprocket alignment is not noticeable.

Grease is still required on the pivot.

James

 

[flecc]

Thanks James, particularly for the shaft length tip. I was intending to add something on the problem with this arm pivot but was holding on until some further info was complete, in case Panasonic had made any changes. I'm also going to add information and an illustration on the correct hole to use for locating the tensioning spring.

Meanwhile we are investigating as many units as we can get hold of since there seem to be some variations, about which more eventually.

So far we've opened up units from a Gitane, a Helkama E2800 and a Gazelle, and Emmanuel and a friend have tried swapping the mainboards between two of the units to see the results. We will be able to gain more knowledge with time and hopefully build a more valuable resource, but things are held up at present since Emmanuel goes on holiday at the end of the week and on his return wants to update his site first with the translation of my webpages on the old unit.
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[JamesC]

Thanks James, particularly for the shaft length tip. I was intending to add something on the problem with this arm pivot but was holding on until some further info was complete, in case Panasonic had made any changes. I'm also going to add information and an illustration on the correct hole to use for locating the tensioning spring.

Meanwhile we are investigating as many units as we can get hold of since there seem to be some variations, about which more eventually.

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It will be an interesting collaboration and I look forward to hearing the news as you both delve deeper.

Regarding the "correct" hole for the spring, I am not sure what the designer had in mind. I have used the hole giving the tighter spring tension on 3 bikes now, and feel it works well. However, it is true to say that it puts more wind in the spring, and may be the reason for the extra pivot bolt length that I mention above.

It continues to provide sufficient tension on a Shimano Nexus NX10 chain after some 1800 "flattish" miles with the wheel still in the same position in the dropouts. I guess that harder riding would have caused more stretch in the chain.

Chain stretch is another thread.

James

 

[flecc]

This is the photo I'll be using James, Panasonic's "hieroglyphics" indicate the recommended position for the spring:


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[JamesC]

This is the photo I'll be using James, Panasonic's "hieroglyphics" indicate the recommended position for the spring:

View attachment 853
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I've a feeling that there may be 2 alternative holes in the alloy casing as well. Can't quite remember.

Great to have the Panasonic library to hand.

James

 

[flecc]

Great to have the Panasonic library to hand.

James

I wish! If I had I'd put it online for everyone as PDFs.

My collaboration with Emmanuel is by no means the first, I have contacts in Germany, Holland, France, Italy and the USA on the Panasonic bike subject, and these idler arm photos came from Derby Cycles in connection with a Rixe problem, obviously part of Panasonic's information to manufacturers. Even they don't enjoy translation though.

I just continuously try to pick up shreds of information to add to the whole.
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[flecc]

Further Updates.

The Panasonic Index Page has been revised to separate the unit's links and include the new pages.

A newly created and extended Maintenance and Repairs Page now covers all the current information on the new units, including modification.
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[Fecn]

Brilliant work Flecc - Keep it up. I'm hoping that your research will eventually reveal some tweaks for the internal electronics as what I really want is to increase the amount of torque from walk-along Panasonic throttle. In it's default configuration it can't even move the bike up the hills I regularly pedal up.

 

[flecc]

Thanks Fecn. That lack of power for the walk alongside throttle is a major disadvantage for those of us who live where the more extreme hills are.

The trouble is that it was an afterthought design addition by BikeTech for their Flyers originally and mainly consists of a bypass of the pedal rotation sensing, leaving the torque sensing in circuit. With no pressure on the torque sensor theres only minimal power available to the throttle.

I've got my doubts whether a software change could achieve what's needed, it's likely that the torque sensing would have to be out of circuit, but that would leave the pedal rotation sensing out as well. BikeTech are astute where these systems are concerned, also creating the high speed versions years ago, both things which Panasonic adopted later, so I think if more hand throttle power was readily achievable by software change alone, BikeTech would have done it.

Still, I'll keep looking in the hope that something will turn up.
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