I did some quick math and based on a vehicle track of 60 inches and not accounting for the change of speed between the two parallel wheels here are some results. The speed difference between the two wheels is greatest at slow speeds and would increase the angle of the out side wheel slightly maybe 4 degrees at the 10 mph example below and to next to nothing at 60 mph. As you can see an Ackerman in tilt won’t work be cause the angle difference changes with speed

Insert:{ The ratio between inside and outside turn radius is directly related to speed of wheels using the same ratio on the lean angle gives the results in {} below. Showing that the faster outside wheel’s desired angle of lean is actually just slightly more than the inside wheel.}

12.5 feet curve radius at 10 mph:

inside wheel lean 38 degrees outside wheel lean 27 degrees

{ inside wheel lean 38 degrees outside wheel lean 40.5 degrees }

42.5 feet curve radius at 20 mph:

inside wheel lean 38 degrees outside wheel lean 35 degrees

{ inside wheel lean 38 degrees outside wheel lean 39 degrees }

362.5 feet curve radius at 60 mph:

inside wheel lean 38 degrees outside wheel lean 38 degrees

{ inside wheel lean 38 degrees outside wheel lean 38 degrees }

If you haven’t all ready, you may want to join the yahoo tilting group http://groups.yahoo.com/neo/groups/tilting/info This is where I get most of my questions answered.

]]>Sorry, I didnt realise you answered me, cos i never got the email confirmation!!

How are you sir? Thanks for answering..

I guessed both wheel speed would have been different if linked in a vehicle.. just wondered if somebody had thougt about that in a leanning vehicle…

See… my main interest, are pedal push recumbent trikes, were weight is a major issue. Adding complicated systems, difficult to build and mantain, is out of the question…

Also adding lean helps taking curves faster but makes the ride less conforting as stability and confort are the major factors to select a three wheeler over 2 ones.

When riding a pedal bike a lot of the effort goes into the equilibrium process. If you add that extra effort to a trike then is no better than a 2 wheel recumbent, as its more weight, parts, building complication etc…

FTC sounds like the way forward, for certain type of rides.. but in an offroad sounds a bit scary…

I was wondering if a dual system could mantain both wheels attached… and still tilt to a degree…

I wanted to test an idea, but avent got a clue how… based on some dutch recumbents called LTE tripod … a semi central pivot for the A arms (wisbone instead of solid arms) that would permit certain degree of tilt in the center frame and back wheel, mantaining both front wheels, pretty much ‘ackerman aligned’ with limited tilting???

anyway im still guessing here.. so thanks for any info you can spill on us, and for your time!!

yours

tx

]]>ok, so heres anopther question…

is there a corelation between the tilt of the wheels and the angle they will turn?

i mean, consider each of both front parallel wheels tilting at diferent vertical angles (same speed, same G’s same everything) would they turn differently, or, has that been calculated anywhere?

could a double angle, one different for each wheel, inside of apex towards the turn and the outside one, turn by tilting at different angles?

yours

tx

]]>There is a direct relationship between the speed, angle of lean and radius of the turn of a two wheel vehicle to keep it balanced. The equation is at the top of this post. also in this post there is a table I made showing results from that equation with Miles Per Hour, Lean Angle, Steer Angle, and the ratios between the steer angle and lean angle.

These are proven by people with way more math ability than me.

Regarding Ackerman: On a reverse trike with the two wheels in front doing the steering the wheel on the inside of the turn will be at a greater angle than the outside wheel because of the difference of the radius of the path the wheels are taking. The wheels should be linked with a tie arm that uses Ackerman. Ideally the wheels would be at slightly different angles of lean, but because Ackerman is most important at slow speeds when leaning is less, everyone I have asked this question seem to think it is not required.

Normal Steer / Free to Caster / Counter Steer

First lets do some basic definitions so we know we are talking about the same thing.

Normal Steer: Angle the wheels to the left to go left, like on a car or conventional non tilting trike. The Can-Am Spider does not lean it is a normal steer vehicle.

Counter Steer: Angle the wheels to the right momentarily to force a two wheel or virtual in line vehicle to lean to the left and then turn to the left. All motorcycles and most tilting trikes are virtual inline vehicles, in other words they work just like a motorcycle. You can drop them to their stops or high side just like a motorcycle too.

Free to Caster: Steering by tilting and allowing the wheels to find through gyroscopic effect the angle of turn best for the angle of lean. FTC solves the problem of the variable ratio between angle of lean , turning angle caused by variation of speed. You steer it like a car, if you are going to wide in the turn you turn the steering wheel more or slow down, just like you would in a car. The down side to FTC is you most likely will need power assist tilting. There is some natural counter steer in FTC and enhancing that is of interest to me.

I hope I answered your questions.

Dave

]]>Hello..

I keep asking people, why the need of free to caster for tilting / leaning steering…??

can someone explain to me, as simple as possible, why both systems, normal steering and tilt steering, cant operate together (as it looks it does in the can-am)?

what are the problematics between this 2 concepts?

do ackerman angles or caster or camber interfere??

when ur leaning into a curve, does turning to counter turn has any negative effect???

please help me out of my mysery/ignorance

cheers people.

Tx

PD. very interesting blog and youtube videos, keep up

]]>Hello Mr. Bailey.

After following your blog and interesting youtube videos, and reading tones about 3 wheel tilt machines, there is a n idea thats buggin’ me. I would like to ask a question to perhapps set a precedent to be studied.

I was wondering if there is any correlation between cornering and the angle a wheel tilt.

I believe factor as speed, G´s, gyroefect etc has to affect but…

How much angle to the vertical of the road does similar wheels at similar velocities with similar mass need to tilt, to perform diferent radius in the same conditions.

Considering 2 wheels, joined together by an imaginary link, same exact dimensions and conditions; same weight height etc.. placed horizontaly side by side running forward at the same speed, if they had to turn by leaning into a curve, describing both different radius (like the ackerman law), to take a vehicle into a perfect cornering, would both wheels have the same angle of tilt?

How can this be tested?

Is there any studies about this?

Has someone thougt on trikes with this in mind??

Sorry if i´m not explaining myself that clearly, but english ain’t my mother tongue and im no mathematician or physicist, just a normal guy from the street with common interests and loads of questions.

hope to hear from you anytime soon

Yours:

Txus

http://www.meanleanmachine.com/leaning-reverse-trike-design/simplified-concept-for-tilting-trike/ ]]>