kind of begs the question, what's the pro's/cons of larger diameter wheels in general (apart from the obvious one with hub motors of less geared reduction required), especially with wider tyres? But that's a whole other thread I think
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The balance generally comes down in favour of bigger wheels on bikes mainly because the dynamic forces are limited at bike speeds, and there's the very big advantage of manageable sprocket sizes. That's why the market has settled on the 26" to 28" size for almost a century now. That 60 tooth chainwheel on my bike is an example of the difficulty with small wheels. To get a higher gear than the 92" I'd have to use that freewheel with the 11 tooth sprocket giving me a 109" but suffering the 11 tooth disadvantages. But if loads are to be carried by a goods bike or a more universal bike like the Q, the small wheel is still a better choice in many ways, and there's big advantages for folders too, size and weight.
If the market was evenly balanced between large and small wheel, the small would have a price advantage too on wheels and tyres, plus the fact that we could have alternatives to spoked wheels more easily, replacing them in 20" or less sizes with motor cycle style alloys or composites.
Do you really notice the difference of the Q bike's marathon pluses over the standard kendas then? (I can feel my fingers itching to switch some more tyres now
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Very definitely, one of the three biggest efficiency gains as said in the website article, but the pressures need to be ok to realise the benefit. In the Q bike I use 60/65 lbs front and 55/60 lbs rear n the 1.75 tyres, but those pressures would give a harsh ride on the Torq's front wheel on poor surfaces because of it's front motor unsprung weight. So if forced to reduce pressures to 45 lbs by that, much of the tyre change gain would disappear into added rolling resistance. That's one of several reasons why I prefer a rear motor, despite it's ride gearing disadvantages, but they are reasons personal to my usage preferences and certainly not universally applicable.
One thought occurs: that effect of larger diameter wheels taking more energy to accelerate them would make them inherently unsuitable for "bursts" of speed (by the time you've got a bit of speed up, you've got no energy left!) hence constant sustained speed/power is more the order of the day, and I guess thats one reason why the Torq is classed as a commuting bike.
A bit off-topic, but that could be another tip for economy of power use on the Torq: accelerating more slowly & smoothly could save some energy & help extend your range.
You've got it in one Stuart. The Torq is far slower accelerating than the Quando, mainly through the optimum motor gearing in the 20" wheel, but with this component added. The Q bike adds another dimension due to the rider also adding more, and that gave me a very scary moment.
On the first occasion of leaving traffic lights with it, and fully prepared in the newly available 57" gear for the start of the lights grand prix, I gave the usual hefty shove down on the pedals with throttle snapped open. The result was the fastest e-bike take-off ever with the biggest sustained wheelie I've ever done on any bike. I don't know who was unnerved more, me or the competing car driver, but I think it was him, for he passively followed me all the way to a roundabout further along and only then drove slowly past peering at the bike.
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