I find bicycle chain a little clumsy. Here is an attempt to get rid of them.
Move the seat backward, right on top rear wheel. Get rid of crankwheel and hence the chain. Pedals now are attached directly to rear axle. Rider now pedals the rear wheel directly.
Lesser things to go wrong and mentain. Now there will be more weight on rear wheel. So it will have to be made stronger.-- VJW, Jan 25 2011 chainless bicycles http://en.wikipedia...i/Chainless_bicycle [xaviergisz, Jan 25 2011] Super Minimal http://www.thecycle...super_minimal_1.jpgDesigned by jruiter + studio, the Super-Minimal city bike has an original frame featuring front suspension, disc brake and a rear planetary hub directly connected to pedals. [baconbrain, Jan 28 2011] Bicymple http://www.bicymple.com/A chainless bicycle [theircompetitor, Oct 13 2012] Sussex bikes http://www.treehugg...ions-by-sussex.htmlChainless- shaft drive. [8th of 7, Oct 13 2012] If the front wheel lifts slightly you'd fall backwards.-- xaviergisz, Jan 25 2011 Presumably this removes the options for gears too?-- Germanicus, Jan 25 2011 You could use a planetary gearbox.-- Wrongfellow, Jan 25 2011 Fair enough.-- Germanicus, Jan 25 2011 All bikes used to be chainless. I'm not sure where the newth is in this idea.-- MaxwellBuchanan, Jan 25 2011 I think earlier bikes used to be front wheel drive; e.g. penny-farthing. This one is rear.-- VJW, Jan 25 2011 Sometimes you just got to ask yourself, "has it been invented before?".-- rcarty, Jan 25 2011 You know the reason why penny-farthings had the huge front wheel? If not look up mechanical advantage. While single speeds and fixies are close to a direct drive, they still have something like 1.5-3 mechanical advantage.-- MechE, Jan 25 2011 Changing gear ratios on the move was a bitch, though ....-- 8th of 7, Jan 25 2011 There were "farthingpennies", with the little wheel out front. As I have ranted elsewhere, bicycles are old technology that was and still is both expensive cutting-edge and simple garage-crazy. You are very unlikely to come up with something new in bicycles, and especially not new and useful.-- baconbrain, Jan 25 2011 Peddles? PEDDLES?
Gotta calm down. Will go mash thumb with hammer.-- lurch, Jan 25 2011 The Hungarian "string bike" from the Wikipedia page in the link is possibly the coolest and most wonderful idea I have seen for three days.-- MaxwellBuchanan, Jan 25 2011 Except for the rear wheels, of course.
"Hey, I just loaned you that bike! What happened to the back wheel?" "Sold it. Why?"-- lurch, Jan 25 2011 Looking at the string bike I see lots of disadvantages for no major advantage (limited power stroke, lightweight cable, reliance on springs in the rear hub).-- MechE, Jan 25 2011 There are hydraulic bikes.-- nineteenthly, Jan 28 2011 One could keep the seat where it is an replace the chain with a pedal-driven gear which meshes directly with a gear attached to the rear wheel. With this system one could still change gears, but you would have to stop completely.
Alternatively if you had front wheel drive you could pop a wheelie, stop the front wheel with the hand brake and change gears without losing your momentum.
If it is just the chainyness of the chain that bothers you, VJW, why not replace it with a belt?-- bungston, Jan 28 2011 Super minimal... so, baked. Which means the idea was a good one. so [+]-- pashute, Feb 10 2011 Baked is not necessarily equal to good.
Besides, the super minimal does have a gear hub, and what looks like it has to be one of the worst riding postures I have ever seen. Way to much weight on the arms, to much of a forward lean at the saddle, and horribly short leg extension. The end result of which would be sore hands, numbness in delicate areas, extreme rider fatiuge in very short distance respectively.
Not to mention it doesn't look like you would want to ride up anything more than about a five degree slope at speed, or you're going over backwards.-- MechE, Feb 10 2011 Also no lights, mudguards, luggage provision - minimal yes (though less minimal than a unicycle), suitable for urban use, no (also less useful than a unicycle I would think).-- pocmloc, Feb 10 2011 How about a friction drive? Leaning forward on the handlebars moves wheel with pedals backward to rub directly on rear wheel. Lean back and disengage pedalwheel for coasting. This way you could easily go backwards and forwards too.-- bungston, Feb 11 2011 Standard pedals and sprocket drive directly meshed transfer gear which drives epicyclic gearbox positioned behind and below crankcase.
Epicyclic box output drives 2 coupling rods or bars set out of phase to prevent "centering". Coupling rods drive cranks on rear axle which contains freewheeling hub.
Gearbox can be detached for servicing without removing wheel.
Sprockets are enclosed, thus protected from environmental damage and can be splash- lubricated (losslessly).-- 8th of 7, Oct 13 2012 Has anyone ever made a shaft drive bike? You could put a CVT on it. I think I found my summer project.-- DIYMatt, Oct 14 2012 Ah, I see there are. Nevertheless, still no CVTs.-- DIYMatt, Oct 14 2012 random, halfbakery