I've never seen a shaft-drive bike, let alone ridden one.
When I first heard of them, I was initially very interested, but a little research indicated that they were pretty inefficient and that such designs are not really 'new', they come and go, like many 'new' ideas in the bike-world. Whether this will happen to the Biomega version, I have no idea, but I'm not hopeful.
The problem is that the parts are design-specific and if the design doesn't take-off, unlikely because of efficiency, it's likely to disappear and then spares soon dry-up. The bikes then become irreparable.
I do recall reading a review that commented unfavourably about shaft-drive efficiency, but I can't locate it. I am also unable to provide objective evidence about the efficiency of shaft-drives. Bearing in-mind the inherent limitations of muscle power, inefficiency is akin to cycling with under-inflated tyres, or the brakes rubbing.
David Hembrow thinks they're inefficient and he's tried at least two, possibly more. http://www.bakfiets-en-meer.nl/2009/07/30/unclear-on-the-concept-2/#comment-2314
Henry at Workcycles doesn't like them either. http://www.bakfiets-en-meer.nl/2009/07/30/unclear-on-the-concept-2/#comment-2315
This is verifiable: They are more expensive and heavier. They have their own disadvantages, like requiring special hubs and difficulty in removing the rear wheel. They really do not have much to offer over hub gears and a full chaincase.
My assessment is: If you have the money and either don't cycle much, or just simply must have one, go for it. If it works out well, well, great! Then write a positive review. But I didn't find any. However that doesn't mean they're universally bad. Otherwise, read Sheldon Brown http://www.sheldonbrown.com/gloss_sa-o.html#shaft and Wikipedia and make a more informed choice.
I must admit, I find it hard to take Biomega seriously. IIRC they have a history of questionable design. The second says everything one needs to know.
http://www.copenhagenize.com/2010/09/pumabiomega-mopion-cargo-bike.html and more here http://www.bakfiets-en-meer.nl/2010/09/24/e-urobike-2010-same-stuff-new-colors/
Superbly made, very pretty, but even then it was known these were items for people who like "nice" things, can afford them, but don't actually ride much.
The limitations of the system are not technical, but inherent in the way bicycles transmit torque to the rear wheel and the laws of physics.
We can improve metals and we can improve tolerances, but we canna change the laws of physics, Cap'n.
6 comments:
I've never seen a shaft-drive bike, let alone ridden one.
When I first heard of them, I was initially very interested, but a little research indicated that they were pretty inefficient and that such designs are not really 'new', they come and go, like many 'new' ideas in the bike-world. Whether this will happen to the Biomega version, I have no idea, but I'm not hopeful.
The problem is that the parts are design-specific and if the design doesn't take-off, unlikely because of efficiency, it's likely to disappear and then spares soon dry-up. The bikes then become irreparable.
Sad, but most probably true. :<(
Why are they found to be inefficient? What exactly do you mean by that?
Kristin,
I do recall reading a review that commented unfavourably about shaft-drive efficiency, but I can't locate it. I am also unable to provide objective evidence about the efficiency of shaft-drives.
Bearing in-mind the inherent limitations of muscle power, inefficiency is akin to cycling with under-inflated tyres, or the brakes rubbing.
David Hembrow thinks they're inefficient and he's tried at least two, possibly more.
http://www.bakfiets-en-meer.nl/2009/07/30/unclear-on-the-concept-2/#comment-2314
Henry at Workcycles doesn't like them either.
http://www.bakfiets-en-meer.nl/2009/07/30/unclear-on-the-concept-2/#comment-2315
This is verifiable:
They are more expensive and heavier.
They have their own disadvantages, like requiring special hubs and difficulty in removing the rear wheel.
They really do not have much to offer over hub gears and a full chaincase.
My assessment is: If you have the money and either don't cycle much, or just simply must have one, go for it. If it works out well, well, great! Then write a positive review. But I didn't find any. However that doesn't mean they're universally bad.
Otherwise, read Sheldon Brown
http://www.sheldonbrown.com/gloss_sa-o.html#shaft
and Wikipedia
and make a more informed choice.
I must admit, I find it hard to take Biomega seriously. IIRC they have a history of questionable design. The second says everything one needs to know.
http://www.copenhagenize.com/2010/09/pumabiomega-mopion-cargo-bike.html
and more here
http://www.bakfiets-en-meer.nl/2010/09/24/e-urobike-2010-same-stuff-new-colors/
Thanks for your extensive research. I will check out your links for sure!
:-)
Sticking with my 1979 mixte for the time being...
http://www.nostalgic.net/bicycle649.htm
Superbly made, very pretty, but even then it was known these were items for people who like "nice" things, can afford them, but don't actually ride much.
The limitations of the system are not technical, but inherent in the way bicycles transmit torque to the rear wheel and the laws of physics.
We can improve metals and we can improve tolerances, but we canna change the laws of physics, Cap'n.
I used to have a biomega like that. I kinda miss it. If I ever go back up over 20 bikes in my coral again I'll probably have to include another.
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