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Bicycles are getting evolved with good technologies or methodologies as the period changes. Now, this one bike, so called string bike has been introduced, which doesn't have chain, derailleur but gears (the website claims so). How efficient this bike will be when compared to the chained ones? Is this one really going to be a game changer? If not, what are all the disadvantages it has?

(this animation says how it works)

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    Check out google trends. If it really was a game changer, would interest in topic stay the same for more than ten years? – Klaster_1 Oct 14 '17 at 11:40
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    It's almost certainly higher friction. – Daniel R Hicks Oct 14 '17 at 12:29
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    @DanielRHicks It has driving rollers on pedals. – HariDev Oct 14 '17 at 12:33
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    Like I said, it's almost certainly higher friction. – Daniel R Hicks Oct 14 '17 at 12:41
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    Looks very inefficient, to me. The whole time, you're pulling against whatever spring causes the string to rewind around the hub. Plus, all the friction from all those mechanical linkages. And they boast about the bike "only" weighing 9kg which is, what, 50% heavier than a weight-weenie superlight bike? – David Richerby Oct 14 '17 at 15:24
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The general idea of "lever drive," or a reciprocating pedal motion instead of a rotary pedal motion precedes even the invention of the modern diamond-frame bicycle--consider the Special Star from 1886. More recently, there was the Facet Biocam, the Alenax, and the Wall Walker.

Within the world of reciprocating drivetrains, the String Bike is interesting in its use of materials (dyneema to transmit power) and the ability to vary mechanical advantage on the lever arm (although the Alenax was able to achieve this simply using hub gears).

But check out what Jobst Brandt had to say about the Alenax. His basic point is that you're converting reciprocating motion to rotary motion, which is mechanically less efficient. I haven't been able to find any studies of the biomechanics of lever-drive bikes.

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    Another inherent drawback to any lever-drive bike is that you need to replicate the entire transmission system on both sides of the bike, while on a conventional bike, you just need one crankarm and pedal on the non-drive-side. – Adam Rice Oct 14 '17 at 17:59
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    It wouldn't take much to test efficiency of the drivetrain: Put power meter pedals on the string bike and put the bike on a Computrainer (obviously using correct calibration protocols) and compare the power data. Repeat with same measurement devices on a regular bike. Repeat for a few bikes. – alexsimmons Oct 14 '17 at 20:37
  • There have always been attempts in 'ameliorating' the basic bicycle design. But any system that has more moving parts is more complicated, heavier, needs more maintenance and is more prone to component failure. The simpler the better. Even moving from chain to belt drive needs special frames and more precise machining. – Carel Oct 15 '17 at 13:56
  • @Carel while in general I agree with you I don't think more parts automatically implies more frequent maintenance. Because what needs the most frequent maintenance in derailleur bikes is derailleurs creeping out of alignment, rather than component failure. – Andy Jul 18 '18 at 4:33
  • @Carel also Veer is producing a splittable drive belt that removes the need for special frames, thankfully: veercycle.com – Andy Jul 18 '18 at 4:34
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I had an Alenax.

I wouldn't recommend the system although it does work.

You have to consciously vertically unweight the rising leg, and it's easy to forget, and stall the pedalling.

  • Welcome to SE - and thank you for sharing your first-hand knowledge of this bike. Could you expand your answer with more info about riding this system? I imagine that riding out of the saddle would be like climbing stairs? How did it work while coasting - or was it driven all the time? Was there any gearing/ratio adjust? Did you ride it long/far enough to get significant wear on it - and what was the difference over time? How did it go when taking off from stopped at a light or similar? Was performance worse or same in the wet/cold/ice ? Did salt make any difference? Was it quiet? – Criggie Jun 18 '18 at 11:49
  • this isn't really relevant because the Stringbike allows you to pedal in a circle instead of pumping the pedals up and down. – Andy Jul 14 '18 at 0:32

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