Bicycle Gear Modifications

As long as I could check out in the pedelec, the electric motor is embedded in the rear wheel hub (some are in the front wheel hub). So, I'm affraid it would not be practical or economically feasible to include a reduction gearbox to the electric motor. But I think you could really change your chain transmission to a more reduced one by changing the front gear (not installing an additional one, but replace the existing one by a smaller - I did something like this in a bike of mine some years ago when I used to be a hard biker: I drilled out 4 rivets, removed the original gear, and in that case installed a bigger one held in place by bolts - because it was a custom hand made speeder/roadster). One bike shop near you could do the job, or just sell you the parts you need. But keep in mind that when you reduce your gears, its more likely (at least to me) that your electric power will last less. You'll be reducing your stress, but the electric motor will continue to try to put you up. Maybe you'll have to control the throttle more softly to avoid ending in a lower level than when you started. If your pedelec has a pedal sensor to dose the power, maybe it would work just fine. Another good way to gain some more meters up would be to ride it "manually" as long as you can, and then turn on the power to help you when things start to go bad. Specially usefull for when you climb to higher levels and start tryingto breath and seems the air is too thick to go in and out of the lungs quick enough... hehehe. By the way, here in Brazil we don't see those pedelecs... looks nice in the photos.

Not in response to the gear issue, but getting more time before your batteries go dead seems to be an issue for you. If the battery is lead acid then you could probably parallel CHARGED batteries to give you more time. I don't know what the bike or battery looks like, but if there is a basket or room for a bracket then this is a modification to consider. Note that whatever charging circuitry you are using will probably be very unhappy if you try to charge a larger bank of batteries than it was intended to charge.

Don't do this without reading, asking questions, etc. and understanding about the battery life, battery SAFETY and charger characteristics.

I don't know about motorised (push) bikes but with racing (push) bikes you can normally get different gear sets for different terrains. So you would get a set for normal terrain with a high speed increasing ratio and a set for mountain climbing with a low speed increasing ratio (maybe even upto 1:1). You can remove and replace the gears from the set with a special tool (for the rear gears). You can get these gears from any specialist bicycle shop.

Perhaps experiment with a change in the wheel size. This will effectively change the effort you must exert at each gear ratio - smaller wheels less effort, larger wheels more effort.

Here's a forum about them: http://www.pedelecs.co.uk/forum/electric-bicycles/

They may be able to help.