Yes there is 3 and 4 but will skip those. Started thinking why there is no 2 wheel drive motorcycles in mass production. There was number of attempts with different ideas and different results. KTM's pneumatic drive, there was some electric motor drive as well. Reason it is never a direct mechanical driver from engine is because we like to steer our bikes. With forks moving left/right making a mechanical drive system would be hard, complicated, heavy and expensive. What about hub centre steering motorcycles then, I think it is quite doable and easy on those. Entire front end stays put on those and only wheel moves which means simple chain drive would do. I had two ideas evolve in my head. Do not know how doable they are. Idea 1, Sprocket is attached to spindle that rotates in front swing-arm. To it in about centre there is a round bearing attached. Kind off like ball bearing that rotates with spindle and by system of groves and cuts drags the front wheel with it. Now to enable steering said inner groves would have to be U-shaped with direction of wheel turn movement and around the bearing attached to spindle. In short said bearing/spindle drives the wheel no matter what angle. Angled U-shaped sprocket allows for free, smooth rim movement around it. Rest of steering arrangement is stock hub centre one. Idea 2, Stationary spindle that is feed through big round bearing that sits inside the front rim. As rim sits on the big round bearing rather then normal flush one it allows rim to move about left right, lean left/right. However it will never be able to move along the rim as said inner big bearing has no where to go being oversized and inside rim. Then it is attached to spindle so it can not slide on spindle via spacers, classic design. Steering arms are attached to rim to push it in correct direction when turning round the big inner bearing. Trick is the chain sprocket and keeping it level. Well for that on one side of rim similar system to idea 1 but only to hold the sprocket level. Again bearing/sprocket design with U-shaped notches to drive the rim at any angle. As centre/hub of the rim would be all but taken up braking system would have to be different. One word "Buell". Do I make any sense? I bet I have now lost a million dollar idea If I could draw I would make a drawing of the main inner bearing I have in mind but I can not plus got beer to finish
get drawing/sketching before you forget/go to sleep (you're not still on tube now?) - tried to follow your line of thought but low on Cocaffeine at this time of night. Re: Idea 1 - how will sprocket at wheel end remain stabilised and aligned with output sprocket and how will it avoid wheel when left or righthand lock applied? Are you going to include a tapped hole in castings for Tax Disc holder?
Tax disc holder would be integral part of design It would go on a sprocket so it would be visible and displayed on left side.
Well the rules state left side, visible (aka not obstructed) and readable but no word about it being readable stationary, on the move or both
Fluid drive must surely have it's day soon. Chains are so old-hat it's unreal, and shaft drive too heavy for bikes, so fluid drive must surely be the way forward - no farting around with conical bearings either, cos the drive 'sprocket' can move with the wheel. Bit of a shitter if you get a leak on the system though...
Yamaha and Ohlins (when owned by Yamaha) tried it, and I rode one for about an hour on an enduro... Horrible, horrible thing, very heavy and the gyroscopic effect of the powered front wheel made it near impossible to turn, it went up muddy hills well but that's it. I think the biggest challenge would be getting someone to adapt to the steering.
Well freak someone adapting to something new will always be an issue I guess. Figaro simplest solution usually work that hydraulic solution looks like loads of pipes and wires. If you were to get a leak you would not only loose power but also traction so I do not see such system going in to production for ages due to possible accidents and legislation. High pressure hot oil, small hill big mist and finally on ass. I see two wheel drive mc's becoming popular when electric bikes start being used daily and have reasonable range/recharge rate.
2wd electric bikes won't be a problem - just stick the motors in the wheels, they're surprisingly small already.
Over the past 100 years many manufacturers have produced 2WD prototypes (e.g. the Swedish Rex-OEC in 1935; the French MGD in 1947; the American Rokon in 1960) or small production runs, using various combinations of chains, shafts or hydraulics. It can certainly be made to work. Ohlins' effort is one of the neatest and most practical. Yamaha eventually decided not to put it into production, and no other manufacturer has come close in recent times. The question is not is it possible (yes it is) but will customers buy it (probably not). On a road bike, when exactly would 2WD be an advantage? Accelerating? Braking? Going at constant speed? Just think about it, and let us know if there are any circumstances in which 2WD would be significantly advantageous.
Pete do not know bikes like BM GS or multi being multipurpose. Having front wheel pulling would also help in case of rear sliding away. Better acceleration, more stable engine braking. Maybe more?
The vast, vast majority of rides are too scared to use the power they've got now, and would have no idea how to use extra traction when there was no shortage to start with - this includes me, by the way. It's a nice idea, but just more expense in most peoples' eyes.
Let's just take acceleration first. If you are accelerating hard, the front wheel is barely touching the ground, and thus has hardly any capacity for transmitting torque. So 2WD can't help much. Next braking. If you're braking hard, modern front brakes can use all the available front tyre grip and more (hence the usefulness of ABS), while the rear tyre is barely touching the ground. 2WD again can contribute very little. Now look at hard cornering. The rear wheel sliding a bit is not too big a problem, and most of us can cope with a little of that. But the front wheel sliding is much more serious and much more likely to result in an off. Let us say you're cornering on the limit, so hard that the rear wheel is starting to slide. The front wheel must be close to sliding too, and will have little capacity to transmit additional torque. Is this the moment when you want engine torque sent to the front wheel? How is this going to help? No, I still haven't found the circumstances in which 2WD would be useful on the road. Obviously dirt riding is different, and that is what Ohlins concentrated on.
