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Pencil_Towel

Chainless Bike

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Given how much their stuff costs I can only imagine this will be ou of my price range...

$90 for 180ml chain  lube

$500 for oversized pulley wheel

$300 bottom brackets

etc

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So, 49% less friction than a normal chain which has <1% power loss.  At 400w that's a 2w saving so it would want to be at very least cost neutral if one were being rational.  Given the normal triathlete's thinking though I think it will make a mint if ever released.

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Stickman......even more $$$ as at this stage its a whole bike with the system as the frame is built around it and not a retrofit.

So if its 500 bucks for a pulley wheel the bike must come in at about a bazillion dollars.

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Nice try, but Nah....

Note that the model shown was as single gear but the final is intended to have a set of 13 concentric gears would work, presumably, by sliding the shaft back and forwards (or changing the length of the shaft) but they don't show how they would do this.  No second chain ring so the range of ratios is likely to be less than a standard deraileur setup.  One advantage of such a setup could be to remove the dishing in the rear wheel but they need that to allow for the diameter of the rear cog.  I am a bit skeptical of the efficiency and I have concerns how it would perform in really dirty, sh1tty conditions - something that the humble chain/deraileur setup excels at.

 

in fact, after having said that i did a bit of googling and there is nothing new on this - shaft drive mechanisms have been around since 1891. There is a whole wikipedia page dedicated to this and they refute the efficiency claims - and a few other gripes as well.

 

Comparison of shaft vs chain
Shaft drives operate at a very consistent rate of efficiency and performance, without adjustments or maintenance, though lower than that of a properly adjusted and lubricated chain. Shaft drives are typically more complex to disassemble when repairing flat rear tires, and the manufacturing cost is typically higher.

A fundamental issue with bicycle shaft-drive systems is the requirement to transmit the torque of the rider through bevel gears with much smaller radii than typical bicycle sprockets. This requires both high quality gears and heavier frame construction.

Since shaft-drives require gear hubs for shifting, they gain the benefit that gears can be shifted while the bicycle is at a complete stop or moving in reverse, but internal hub geared bikes typically have a more restricted gear range than comparable derailleur-equipped bikes.[8]

Most of the advantages claimed for a shaft drive can be realized by using a fully enclosed chain case.[ Some of the other issues addressed by the shaft drive, such as protection for clothing and from ingress of dirt, can be met through the use of chain guards. The reduced need for adjustment in shaft-drive bikes also applies to a similar extent to chain or belt-driven hub-geared bikes. Not all hub gear systems are shaft compatible.

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27 minutes ago, trilobite said:

Maybe be less maintenance than a conventional chain?

But if it stuffs up it'll be a bitch to borrow a spare one to get you through to when the bike shop can get you a new one in.

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The improved efficiency over older shaft set ups is due to the use of small roller bearings at the interface with the cog. But so far only single speed, which doesn't exactly have much in the way of efficiency losses anyway. The multi gear option is just a drawing, no actual working model.

Publicity at start of TdF. Everyone does it.

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38 minutes ago, Alex Simmons said:

The improved efficiency over older shaft set ups is due to the use of small roller bearings at the interface with the cog. But so far only single speed, which doesn't exactly have much in the way of efficiency losses anyway. The multi gear option is just a drawing, no actual working model.

Publicity at start of TdF. Everyone does it.

Bit further than a drawing now, but how it goes on the road I don't know. When you see the cut-away section though, it looks like the perfect place to hide your motor. ;)

 

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1 hour ago, Alex Simmons said:

Still no gear changing.

Show me someone decent doing a full gas standing start with it and I'll pay a bit more attention.

Agreed. They show a few gear changes with no real stress on the gearing, and that's it. All the video's I've seen show someone riding it in the still shot at the start of the video, but you never actually see anybody putting it to the test. Looks can be deceiving, but it doesn't look very strong to me. I'd like to see what a strong sprinter could do to it.

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Also looks like it will have very little tolerance, as soon as anything is slightly out of aignment I’d imagine friction would go through the roof.

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My video on this from Eurobike just sailed passed 675k views.... which is insane for a product that'd shred in seconds (my wife actually messaged me to go break it while I was at the show... that's why she's my wife) :)

It's super cool to look at and spin with your hands. I don't think we'll ever see someone spin this in anger with their legs. 

 

 

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Did you not watch the video?????  It doesn't have legs, it has gears and a driveshaft!!!

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