Project Q bike

[flecc]

Thanks FatMog, but you are all most definitely worthy. I'm a great believer in open source and shared knowledge, since I believe that in principle all knowledge belongs to all people, simply because the content of the knowledge has always existed and cannot be owned by anyone. Now I bet that causes some head scratching.
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[flecc]

Hi Paul

There were some similar motors around, but yours sounds different. Mine didn't have a band brake thread, just a plain steel drum.

Yes, definitely address the bike efficiency first.

For example, lash your motor into a club rider's slim tyred efficient bike and it will really motor. Add your power and it will take off even better yet.

Then switch it into a knobbly tyred full suspension mountain bike and you'll wonder what went wrong with the motor. Now pedal that and wonder where your strength went.

That's an extreme example, but there are degrees of that with every bike that's less than fully efficient.

[flecc]

Originally Posted by Mike Robinson

I presume it's called a Q bike because of "Q cars" which are supposed to look ordinary but are fitted with powerful motors and running gear to have higher performance.

There were also "Q ships" in WWII which looked like ordinary freighters but instead were heavily armed to knock out German subs.

Of course it may just be because you just got tired scrapping the letters off the frame of your donor bike the Quando.

Mike

I posted it on the introduction Mike, you must have got tired of reading. Here it is:

"Why Q Bike? Well, it's derived from the Quando, and like the police Q cars, it's capable of much more than it seems to be at first sight."
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[coops]

Thanks again for your answers flecc, thats much clearer now. I think my brain must have gone into info overload: I completely forgot about the wheel rotation energy thing 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 .

I remember when I got round to changing the knobblies on my MTB to semi-slicks: wow! the difference was amazing! It just felt like a different bike altogether! Swapping the Torq tyres for marathon plus would make a difference I'm sure, though probably not as big as knobblies to slicks . 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 ).

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:-).

Stuart.

[allotmenteer]

Originally Posted by flecc

Hi Paul

There were some similar motors around, but yours sounds different. Mine didn't have a band brake thread, just a plain steel drum.

Yes, definitely address the bike efficiency first.

For example, lash your motor into a club rider's slim tyred efficient bike and it will really motor. Add your power and it will take off even better yet.

Then switch it into a knobbly tyred full suspension mountain bike and you'll wonder what went wrong with the motor. Now pedal that and wonder where your strength went.

That's an extreme example, but there are degrees of that with every bike that's less than fully efficient.

I'll post some pics of my motor and will try to work out the gear reduction etc. I suppose most geared motors look similar inside as there aren't many different ways to design a motor.

Yes, the first thing I did was to put slicks on the bike and as you say the difference is astounding, probably the best and cheapest improvement you can make to an electric bike.

Paul

[halfmedley]

Excellent stuff as always Flecc, thoroughly enjoyed reading about your Q bike.

Commuting to and fro on my ebike has made me aware of the compromises inherent in an 'off-the-shelf' machine. I was even beginning to wonder whether a converted regular bike into an e-regular might bring about a cycle better addressed to particular needs/specifications.

However project Q raised a particular thought: might there be some business in this? (Don't worry I'm not suggesting that you start churning out custom bikes for people, unless you'd like to..!)

Your Q bike clearly shows that an 'off-the-shelf' machine can be super-upgraded (above and beyond the usual tyre and saddle replacement) into something rather special at reasonable expense. So my thought was, perhaps a dealer might offer a similar service (and charge accordingly) alongside selling the standard factory stuff?

[rsscott]

Originally Posted by halfmedley

...So my thought was, perhaps a dealer might offer a similar service (and charge accordingly) alongside selling the standard factory stuff?

Kind of like a Motorsport or AMG division equivalent for electric bikes

cheers
Russ

Russell Scott
Pedelecs UK

[flecc]

Originally Posted by coops

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 .

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.

Originally Posted by coops

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 ).

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.

Originally Posted by coops

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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[nigel]

BY halfmedley
So my thought was, perhaps a dealer might offer a similar service (and charge accordingly) alongside selling the standard factory stuff?
Thats a great ideal
i would love to buy that model now with the changes flecc has made it is now a good alround bike i hope flecc can maybe get other parties intrested in taking his project on to the next step.NIGEL.

[flecc]

Thanks Halfmedley. I'm sure there's potential for a manufacturer to market better like this for slightly more, hence my saying that I'd like eZee to do it.

But for a bike dealer it wouldn't be very practical because of the costs involved, making the end price prohibitive. My £286 was just the net parts cost, but if Id added my labour at a viable business rate it would multiply hugely.

There are some examples. The SP Brompton which has very few changes from the original at around £500 or so max, costs about £1200 from the specialist who produces it. There are a few folder fanatics who will pay that or even £1800 for a Moulton or the like, but I don't think we are yet at the stage of a commercially viable number of e-bike extreme enthusiasts, though some of us show signs of infection.

Referring to Russes comment, if the International or UK HPVA introduced e-bike racing classes and they became popular, it could be different.

(HPVA = Human Powered Vehicle Association, administrators of cycle sport for those machines not recognised by the UCI, recumbents etc.)
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