Changing the size of the motor gear does what on a Panasonic Mid Motor?

[fire_strom]

Hi
More questions, thank you very much.

I read Flecc's great description (thank you sir) of the way Panasonic Mid Motor systems dole out their assistance and was surprised at how low the cadence was where it was optimal. I think with my 2012 36v version that has been increased but I still find that I like to spin the cranks faster than the system wants to assist. Would changing the size of the motor cog allow me to pedal at a higher cadence and still get assistance?
Is there a down side to doing that? I have seen in the descriptions for the cogs online that it is not ok to change the size to increase speed. That isn't really my goal. I just like spinning. Can someone explain how the size of that motor cog effects the system, please. I am having a hard time wrapping my head around it.

Thanks again,
-G

 

[flecc]

Yes, your 2012 model is slightly changed in cadence from the original.

If you increase the motor sprocket size it will increase the cadence and power assisted road speed. To avoid the road speed increase just increase the size of the rear hub sprocket(s), which retains the increased cadence.
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[fire_strom]

Thanks! Is there any down side, complications, or damage potential in doing it?
-G

 

[flecc]

No, in fact a larger motor sprocket brings some advantages, less wear and much less likelihood of the chain jumping the teeth than with the standard 9 tooth one. An 11 tooth is a good step up, not going too far.

Bear in mind that if your present transmission has some wear, the new sprocket and lengthened old chain might not mate up too well. If that's the case, you might need to renew the chain and rear sprocket(s) at least at the same time, and possibly also the chainwheel.
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[fire_strom]

Thanks again flecc. I currently have an 11 or 12t. I am thinking I'd try going up 2 or 3 teeth. Is that reasonable?
-G

 

[Kenny]

I swapped my 11t for a 13t when I found I was spinning past the power cut off on my 2011 Agattu.
It rides great now and the few extra mph is welcome
I'm sure the motor could handle a 14t too, if you've a really fast cadence.

 

[flecc]

Thanks again flecc. I currently have an 11 or 12t. I am thinking I'd try going up 2 or 3 teeth. Is that reasonable?
-G

Yes, that's reasonable, as Kenny says up to 14 teeth can be ok if the cadence suits.
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[fire_strom]

Thanks guys, I really appreciate the guidance. I'll try 14t.
-G

 

[Kenny]

It's a cheap and very easy mod. I bought mine here :

http://www.ebay.co.uk/itm/Motor-pinion-9-10-11-12-13-14-15-Z-for-all-Panasonic-Pedelec-Motor-/331398335978?var=&hash=item4d28e14dea

If it doesn't suit you, just resell it.

 

[fire_strom]

Thanks again all. I got a 14t coming. We'll see how it goes.
-G