Rough Terrain off-road e-bike

[flecc]

No sooner had I posted that what is needed for the really rough stuff is a bike with mid motor and battery than one turns up. This is what I meant, a bike with full suspension protecting the motor, drive and battery from shocks. This is a very neat implementation with the 13 Ah NiMh battery in the mainframe tube, so all the weight in the middle.

NiMh is best for high low speed current loadings as well, and with 13 Ah it will probably have plenty of low down punch. I hate to think how much it could cost here though, and it certainly won't answer my call for a low priced bike of this kind:

M55 Bike
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[jac]

certainly looks the part wonder if it will be any good or just flash in the pan
jim

 

[flecc]

A great design for the job, but probably too pricey Jim.
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[silversurfer]

"But a Very pretty web site, Gromitt" as Walace would say, Silversurfer

 

[flecc]

It certainly is silversurfer, and I suspect that same quality is in the product, since it's design is right on target for purpose.

In this country, for lottery winners and rich kids probably, the price reflecting the quality elsewhere.
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[Miles]

I wasn't that impressed with the website, myself..... over designed, slow, and with very little information...

Will be interesting to see what the bikes like, though..

 

[flecc]

Certainly was slow, and also not to my taste, but I think that sort of web design is good for that particular target audience, especially those who can afford the bike and max speed net access.
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[Miles]

Anyway, it's great that genuinely different new models are appearing, now.

 

[flecc]

Anyway, it's great that genuinely different new models are appearing, now.

Hear hear, long overdue. For too long the "me too" school of design has ruled.
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[silversurfer]

? Hi guys, that’s why I said 'pretty'.... very smart and slick page, (if a little slow). BUT, frustratingly lacking in info. If they could do that standard of web page motion why could they not put a few decent pics in, of some of the 'works' and a bit more hard info? At the moment a menu, without any prices....
Seriously, a well suspended central power source seems sensible, looks like the batteries are loaded down the main vertical tube/s. (10 'd' cells end on measure about 65cm/26"). Are they 'd' cells? They look sort of 'oversized'. However, 24 volts makes for more mass in the motor assembly than 36v?
I have noted flecc's previous comments on the failings/lack of efficiency of motors driving via the pedal crank/main chain drive; the stress of pedal plus motor power , particularly when interruptions for gear changes, so I am genuinely interested in why this machine is potentially so good ? Will 200 watts give it the 'grunt' that it's looks implies? silversurfer

 

[flecc]

They'll be F cells silversurfer, with that capacity.

On the efficiency issue, it's horses for courses. On road as I've said, drive through the gears is less efficient, since most of the time is spent where a hub motor driving the wheel direct is at maximum efficiency, so no transmission loss.

For rough off road use, gears would be necessary to match the maximum torque point (about half revs) to the low speed necessary for some conditions. It's like the case I concluded my article on, where a steepness of hill and weight to go up it is beyond even the most powerful hub motor. Then gear drive has to be used at the cost of efficiency loss elsewhere.

On an off road bike of this sort, the on road full speed inefficiencies don't matter much, simply because that's not the design purpose of the bike. It's very much like the difference between a tractor and a car, each very inefficient when trying to do the other's job, their efficiencies matched to purpose.

The 200 watts is a notional figure of average use, for legal reasons only. The true peak power could be three times that, and the large capacity battery is good for "grunt" since it's power delivery is less restricted, all other things being equal.
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[silversurfer]

Thanks for that, I appreciate what you say, excellent comparison;tractor to car. I ran an old series 2 land rover for years and very occasionaly needed 'low ratios'. But the extra torque, especially if gear changes were req. put a lot of stess on drive train. I was unlucky enough to once have a half shaft snap on a low ratio boat pulling manouver.
Refering this to bikes, I wonder how the power is managed at the points when the pedal gears need changing, is there a declutching or perhaps an overun clutch on the motor? silversurfer

 

[flecc]

There won't be any declutching, but that won't matter too much since they've wisely chosen a derailleur where drive needs to continue for a change to complete. The wear will be very high with the dual power fed though the transmission, but that's a cost of that bikes purpose. The chain and sprockets will be running in bad conditions anyway when used as intended, mud, water, grit and dust in any combination as an excellent grinding paste to hack into the metal.

Even the toughest hub gear wouldn't survive this particular application, and wouldn't be suitable anyway due to the loss of drive at changes, the worst possible thing in many off road circumstances.
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[silversurfer]

Thanks for that flecc. all is clear ! it's 10 to 1, I'm off to bed, night-night !!! silversurfer