Friction Drive comes of age

[Tugwell Gibson]

Not quite, there's the several all-in-one wheel solutions like the Copenhagen wheel. That is just a front wheel quick release swap with smartphone control, even quicker that this friction drive gadget.
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Can't be bought though can It?

 

[flecc]

Can't be bought though can It?

Nor can this one in this thread, both are armchair solutions!

But some of the Copenhagen type wheels are crowdfunded witn purchase options, so a few may have them now since they've been around for quite a while, just as a few have Kepler's one to try. Indeed the Copenhagen wheel is available to try out in the USA and can be ordered.
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[Danidl]

Nor can this one in this thread, both are armchair solutions!

But some of the Copenhagen type wheels are crowdfunded witn purchase options, so a few may have them now since they've been around for quite a while, just as a few have Kepler's one to try. Indeed the Copenhagen wheel is available to try out in the USA and can be ordered.
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If smooth rollar slip on wet wheels and abrasive rollars shred tyres , what about customised sleeves with the reverse pattern of the tyre embossed on them? Then knobby tyres could be used

 

[flecc]

If smooth rollar slip on wet wheels and abrasive rollars shred tyres , what about customised sleeves with the reverse pattern of the tyre embossed on them? Then knobby tyres could be used

I wouldn't claim that a smooth roller will necessarily shred a tyre, correctly applied pressure to power ratio and tyre pressures in dry conditions shouldn't cause any tyre damage.

The nearest to that embossed roller idea that's been tried was on the Sinclair-Goddard* Power Pak add-on motor of the early 1950s that I used to sell and service then. That had an alloy roller with square edged transverse ridges to engage with suitable tyre treads.

That was the worst of all types for shredding tyres in wet conditions, and the first company to go out of business then. The idea may have potential with precise matching of tyre tread and roller, but I fear would bring considerable inefficiency in dry conditions due to sliding friction between metal teeth and rubber tread as each engagement took place. Basically it's high friction gearing.

* Nothing to do with Sir Clive Sinclair.
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[Danidl]

I wouldn't claim that a smooth roller will necessarily shred a tyre, correctly applied pressure to power ratio and tyre pressures in dry conditions shouldn't cause any tyre damage.

The nearest to that embossed roller idea that's been tried was on the Sinclair-Goddard* Power Pak add-on motor of the early 1950s that I used to sell and service then. That had an alloy roller with square edged transverse ridges to engage with suitable tyre treads.

That was the worst of all types for shredding tyres in wet conditions, and the first company to go out of business then. The idea may have potential with precise matching of tyre tread and roller, but I fear would bring considerable inefficiency in dry conditions due to sliding friction between metal teeth and rubber tread as each engagement took place. Basically it's high friction gearing.

* Nothing to do with Sir Clive Sinclair.
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Interesting, what I was thinking was in terms of a rubber sleeve with its outside surface profiled with the reverse of the pattern of the tyre.These patterns replicate themselves a few times per circumference. When it engages with the tyre, the roller would slide until it locked to the pattern and then could be effectively be a gear. Using modern plastics it should be feasible to manufacture these sleeves, .. I was thinking in terms of photosetting resins.

 

[flecc]

Interesting, what I was thinking was in terms of a rubber sleeve with its outside surface profiled with the reverse of the pattern of the tyre.These patterns replicate themselves a few times per circumference. When it engages with the tyre, the roller would slide until it locked to the pattern and then could be effectively be a gear. Using modern plastics it should be feasible to manufacture these sleeves, .. I was thinking in terms of photosetting resins.

As you say, like a gear, but of course all gear teeth have a sliding pair of surfaces as they engage and disengage. With one of those surfaces rubber, I predict a substantial efficiency loss due to that sliding friction.
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