Project Q bike

[flecc]

No, the smaller wheel bikes aren't better hill climbers John, that's the red herring I referred to. The only thing that matters in this context is the gearing. With a motor, that's the gear ratio between the rotor and the road surface, and with a rider, the gearing between the rider and the road surface.

The intermediate means are not material, except in as much as they add inefficiency, and in this context the small wheel is marginally less efficient. Hence the use of large wheels where efficiency is important. In the Tour de France, riders are free to choose bikes suited to each stage. For the time trials they use carbon disc wheeled bikes for example. If small wheels were better for climbing, they'd use them in the Alpine stages, but they don't, precisely because the larger wheel is always better.

I've only mentioned the way in which road irregularities produce a permanent hill climb simulation, but there's also the matter of bearing friction and grease/oil drag. A small wheel turns faster, so it's less efficient on both those counts.

I haven't in any way proved small wheels are better for performance, only mentioning how they aid load carrying due to the low centre of gravity, and can be useful in towing by providing a lower hitch point, so they have minor utility advantages.

What I've shown is that by taking the best available motor, and then improving the donor bike's efficiency as much as possible, a really good performance can be achieved. But it's important to note the Quando was already the best legal full speed hill climber anyway, but without rider gears the rider couldn't aid that. By adding efficient rider gears, the already best hill climb performance has been increased to well beyond the usual standard of e-bikes. If there had been a 26" wheel bike with the Quando motor geared to achieve the identical speed of the 20" Quando, I could have made that more efficient.

I'm at a late stage of a performance project on the 28" Torq, so I have no small wheel bias in that respect. The fact is that as I well remember at the time, Alex Moulton had a "bee in his bonnet" which no-one else in cycle design shared. It wasn't about folding bikes, which he didn't even consider at the time, but just a notion that a small wheel would produce an aerodynamically better bike, even to the extent of enclosing one in a sort of aero fusilage! It was a crazy flawed notion. However, by showing that 20" wheels could get somewhere near 26" and 28" ones for efficiency, he did open the door for folder designers.
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[coops]

@ flecc: You beat me to it answering . Re your earlier post, that's good to be clear about it: I was starting to think that the smaller wheel gave some additional advantage in hills. I agree about the "rolling" pluses of larger wheels - the great benefit of m+ on the Q shows up that limitation of smaller wheels which will be proportionately more highly disadvantaged by higher friction tyres.

In some ways I prefer a 26" wheel, and they're a more common size I think? Especially in MTBs.

I have other questions regarding motors: that subject has come up elsewhere recently, but since they're not directly related to the Q bike I may start another thread for those .

@John: Seems I was looking in the wrong direction both times i.e. not the wheel size affecting motor dynamics or the pedalpower transmission to a great extent, but the motor quality & gearing being important. I think what flecc is saying is that its not the wheel size that improves hillclimbing or torque, but having a quality motor suitably internally geared for the wheelsize: e.g. a quando type motor with lower internal gearing i.e. for 200-215 rpm in a 26" wheel giving same max speed of 15-16mph, may actually perform better overall than the 20" wheel, 260-280rpm 15-16mph Q (because they have equal gearing and torque for hills but a larger wheel always rolls more easily) - even if both bikes are equally chainwheel drivetrain geared for pedalling.

Now, what makes a good motor...? New thread for that I think .

Stuart.

[flecc]

Originally Posted by coops

I think what flecc is saying is that its not the wheel size that improves hillclimbing or torque, but having a quality motor suitably internally geared for the wheelsize: e.g. a quando type motor with lower internal gearing i.e. for 200-215 rpm in a 26" wheel giving same max speed of 15-16mph, may actually perform better overall than the 20" wheel, 260-280rpm 15-16mph Q (because they have equal gearing and torque for hills but a larger wheel always rolls more easily) - even if both bikes are equally chainwheel drivetrain geared for pedalling.

That's exactly it Stuart!

Originally Posted by coops

Now, what makes a good motor...? New thread for that I think .

Stuart.

Just look at the Quando motor pictures if it's performance that's wanted. Not necessarily the best for consistency though.
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[coops]

Originally Posted by flecc

That's exactly it Stuart!

See, I'm learning! Glad I got it clear now ...

Originally Posted by flecc

Just look at the Quando motor pictures if it's performance that's wanted. Not necessarily the best for consistency though.

... errr.. except you've lost me there flecc I'm afraid: I've seen the pics, but what do you mean by motor performance & consistency, and how are you differentiating?

Stuart.

[flecc]

Originally Posted by coops

... errr.. except you've lost me there flecc I'm afraid: I've seen the pics, but what do you mean by motor performance & consistency, and how are you differentiating?

Stuart.

See the wink smillie Stuart, I'm being diplomatic, consistency not referring to performance but other things that motors can exhibit.
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[coops]

Ok, thanks flecc - I feel a bit dim now, but non-verbal gestures can be more difficult to twig

Stuart.

[coops]

Are we getting any closer to guessing the "hidden element" of the Torq project the flecc?!

It occurrred to me that you might have somehow regeared the motor for lower speed, as Ian said before, except it was mooted before that 26" or 24" wheels may be involved, but at the time the design was not finalized... so....

24" or 26" wheels would surely involve either major frame surgery or the motor transplanted to a donor frame but you hinted that

Originally Posted by flecc

Quote:
Originally Posted by coops
One thing though: when you say "radical", is that in the sense of major "bike surgery" not for the faint-hearted, or very clever and far-reaching but simple, or very expensive?

Only the words in red.

major bike surgery not involved?

So transplant or internal motor surgery then???

I'm going to start a guessing thread tomorrow! The world can wait no longer to hear the latest in radically clever ebike developments!

Stuart.

[flecc]

No, not even close Stuart, and a smaller wheel was ruled out very early. Weather permitting for testing,the T bike project release is so close it's not worth trying to guess. Post permitting, the final three parts arrive this morning so after a couple of hours work I may be on board this afternoon. Some areas have already been tested though, but the entirety will reveal the overall benefit.

As I promised, what I've done is truly unguessable, as I'm sure you'll agree when the shocks are revealed.

However, although it's radical, it's not unconventional! Work that one out!
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[coops]

Originally Posted by flecc

No, not even close Stuart, and a smaller wheel was ruled out very early...

As I promised, what I've done is truly unguessable, as I'm sure you'll agree when the shocks are revealed.

However, although it's radical, it's not unconventional! Work that one out!

Oh well.... where's Sherlock Holmes when you need him? Eliminate the impossible, and whatever remains, however unlikely must be the truth? So, no change in wheel size - I thought that wouldn't be radical enough no regearing of the motor internally... "shocks" revealed eh? Something electrical eh? But that doesn't sound too conventional.... hmmmm!

Alright, I'm not guessing anymore! Honest! But does it still contain the two big surprises alluded to before, or has that changed - maybe they've multiplied?! And it still slows the Torq down a bit & assists its hill-climbing?

Can't wait!

Stuart.

[flecc]

It hasn't slowed it down.
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