Recumbent - A question re. steering mechanics

Every bike I have ever seen steers with the front wheel(s). This is true whether the bike has two, three or four wheels. I'm just wondering about this, because in the world of recumbents, it would seem that it would be simpler (mechanically) to drive a fixed front wheel and steer the rear wheel. Obviously this would shorten the chain by a great deal and possibly reduce weight all around.

However, I wonder what the steering would feel like. Would it be as stable, and as predictable as front-wheel steering? Could it possibly make for tighter turning circles?

Surely there must be a reason why every bike is made with front-wheel steering, I'd just like to know the reason.

Mostly because it's almost impossible to ride a rear-steered bicycle. But what's wrong with FWD, with standard steering? There are a few examples out there. Zox recbuments are FWD, as is the Barcroft Oregon and Cobrabikes. Cruz Bikes sells a kit that converts a dual-suspended MTB to a moving-bb FWD recumbent.

Here's Sean Costin on his homebuilt 'twist-chain' FWD.

Weird, so you basically have to twist at the waist when you want to turn? And, is pedal steer a problem in that case?

Weird, so you basically have to twist at the waist when you want to turn? And, is pedal steer a problem in that case?
Sort of, at least with the moving-bb type where you have to reach the outside leg around the steerer tube on tight turns. That type has a lot of pedal-induced steering, too. Users report that they learn to compensate by pulling on the handlebars. I don't know if I'd call it a problem; at times it would be obnoxious, at other times the capability of no-handed steering would sound pretty good. The fixed-bb type, like Sean Costin's, doesn't have any pedal steer. That style has a pulley/gear near the steerer tube and the power side of the chain runs along the fork blade. The chain must twist during turns, but modern chains seem to be able to handle that OK. Here's another homebuilt that uses a fixed-bb design.

As you can see, FWD simplifies chain routing, and without worrying about the chain path, you can put the seat down pretty low - this seat is about 9" off the ground.

The main reason there aren't any bicycles with rear wheel steering is probably that it would be very dangerous. The rear of the bicycle would have to go in the opposite direction from the direction you want to turn. So, if you wanted to turn right and there was a car passing on your left, the car would hit you.

If you got too close to anything like a curb then you wouldn't be able to turn away from it without going backwards. With front wheel steering the front goes where you want to go and the rear just follows - that's a whole lot safer.

You could probably learn to ride a bike with rear wheel steering although it would be really confusing at first. It would probably be more efficient for the reasons you gave - a shorter chain and probably a pretty simple steering mechanism. But it wouldn't be practical.

There was a car, the Isetta, that I believe had rear wheel steering BUT it was triangular, with the back being narrower than the front, and it had a real short wheelbase. These two things combined to minimize the danger of the back swinging the wrong way in a turn. Another interesting feature was that the door was on the front of the car - it was barely a car - more like a backwards tricycle (a tadpole) with a body and an engine).

The problem with rear-wheel steering is that it is not inherently stable, and there is no mechanical way to "fix" the problem.

There is a page somewhere online showing various rear-wheel steer bikes, some commercially-manufactured examples from the past and also some home-built. Most all of the commercial ones shown are no longer sold, because they were found to be too dangerous. Many of the homebuilts have been found to be dangerously unstable; a couple are unrideable--even though learning to ride them would seem to be a simple matter.

[edit: link added]
http://wannee.nl/hpv/abt/e-index.htm

Hi Jeff-o,

Howzabout a recumbent tadpole style trike with dual steering capabilities? It's called the Sidewinder. I've never ridden one, but I read a review on it(RTR magazine, I believe), and word was that it was a lot of fun!

Check it out:

Sidewinder (http://www.sidewindercycle.com/store/comersus_viewItem.asp?idProduct=25)

:)

Ah, cool, front wheel drive. That would be fine. :)

As WheelDoctor observed in another thread, threads often drift away from their original question. This one seems to be doing it, too; so here's my contribution to the drift. As FWD goes, I was always impressed with this trike:
http://www.aha.ru/~ykpro/index.htm

It's still front steered, though.

As WheelDoctor observed in another thread, threads often drift away from their original question. This one seems to be doing it, too; so here's my contribution to the drift. As FWD goes, I was always impressed with this trike:
http://www.aha.ru/~ykpro/index.htm

It's still front steered, though.

Yep, I know of that one, too. I love reading the broken english on that site, though I do appreciate their attempt to translate. I wonder how much one of those trikes weighs? Does anyone on this forum own one?