MrInitialMan

On tadpole trikes and quadricycles, what is the range of angles on the steer wheels (assuming 0 degrees is straight ahead). I've been trying to work out the steering on my quad, and I'm wondering how far to let the front wheels swivel.

HillRider

Along with the maximum allowable angles (which I can't help with) bear in mind that both wheels shouldn't turn in parallel since the inside wheel will describe a smaller radius than the outside and must be angled accordingly. Here is Wikipedia's description of that requirement: https://en.wikipedia.org/wiki/Ackerm...ering_geometry

Andrew R Stewart 

I have never seen this question answered in a spec list or an article. So going only my memory of servicing and then test riding a number of tadpole trikes over the years I'd say the ft wheels steer no more then 45* on the average, maybe as little as 30*. Andy.

MrInitialMan

Thank you. That's a huge help.

dabac

Depends a bit on the scope of your question.

The amount of steering angle used while actually riding is quite small. Plenty of regular bikes with plenty of toe overlap that are used w/o problem.
But then there is - let's call it "off-bike handling".
A bike that'll ride just fine at speed might be a real nuisance to jockey around by hand, or during start/stop manouvers.

Construction allowing, I'm struggling to come up with a scenario when a bigger angle would be a problem while riding, while it's fairly easy to think of a situation when a narrow angle would make off bike handling awkward.

What I'd do would be to determine how tight my "average" u-turn on a regular bike is. Then see if the design can match that turning radius.

If it does, you wouldn't need any road behaviour retraining when using your quad.

Andrew R Stewart 

I find that the trikes I've ridden (granted this is after servicing side street test riding) tend to need far more steering range then a double diamond upright bike. Trikes are far more difficult to maneuver when stopped. Far more a challenge to get off and pick up and turn around or point this or that way. So the ability to turn within a traffic lane, or to follow a turn off a side walk and onto a walk up to a house (as example) is far more needed then any "normal" bike does.

Recumbent Bikes | Recumbent Bicycles | Recumbent Trikes | Tandem Recumbents | Recumbent Exercise Bikes | Crank Forward Bikes | Hobie Kayaks - The Bicycle Man has the largest selection of Recumbents In Stock to choose from in New York State. here's a link to Peter Stull's shop. He has been selling recumbents for decades and took over the manufacturing of some many years ago. I suspect he has much more experience is these design maters. he's a nice guy and I would think he'd offer his views. Andy.

MrInitialMan

It's actually for a quadricycle, with a ~70" wheelbase or so. ((Haven't actually measured my model yet, but that's my rough guess to how long the wheelbase is going to be)

MrInitialMan

Any suggestions for something of that length of wheelbase?

nfmisso

Measure a small car, such as a Fiat 500 - just go to the dealership and ask to see how tight it can turn.

davidad

I measured a friend's Greenspeed and the angle is 15 degrees.