A NEW SPIN ON AN OLD STYLE FLEXIBLE

Death wish.

After more than 110 years of sidecars in the world, Just about everything has been tried.
There is a reason that system is not in production. It is deadly.

you might be a little bit wrong there old mate, have you heard of kalich leaners,

I understand in the early days there wasn,t the yrs of experience behind them we have today,and the old flexi,s used 2 arms running parallel to each other which would have had a lot of accentuated movement over the distance they where running,,

and the fact that a lot came unstuck in the snow and ice or mud on the roads of the day,, here at home in Queensland in the middle of winter it gets to 0 degrees twice the whole winter season, and I,m not really into freezing my bum off in Alpine environs so icy conditions won,t really come into play, apart from the way I ride is steadier than grandad

I enjoy thinking outside the box and using the unusual like my outfit trailer

so if we were to leave the design of the actual chair out of the equation and just focus on the wheel base and front link set up, is there any calculated equation why it won,t work?

I just can't imagine a no trail steering system being stable. I think you would be risking tank slappers.
Sidecar wheel steering has been made successfully, but I have never heard of it on a flex.
In the twenties, flexis were raced with a passenger monkey. After losing a number of passengers in crashes the rule was changed to allow a 75 pound sand bag in lieu
of a passenger. Finally the sport of racing flexes was deemed just too dangerous. The problem is that if you begin to slide out of control the flexing of the sidecar may
make it impossible to regain control in time to prevent a crash.
A few months ago a fellow wrote about wanting to build a very simple flexi on a Honda Ruckus. He was not going to change in the rake and trail.
I think he may have a workable design in that he is not expecting speeds much above 20m MPH. At bthe reduced speeds things are not likely to get too badly out of control
but if they do it is not likely to be fatal or even serious injury. I have built a mini bike with sidecar many years ago so I have some experience with 20 MPH problems.
I have had ten sidecar rigs in the last 40 years, 5 of them I built from scratch, two were factory rigs and three were factory sidecars that I made all the mountings for.
One of my scratch built sidecars I once had over 100 MPH and still stable, so I do have some experience with over the road rigs and off road rigs.
I thought about flexis a few times but my researches always caused me to drop the idea.
One of the safeties of a conventional rig is that if for any reason you should find yourself in a slide, the sidecar has a stabilizing effect instead of the bike trying to lay over
one way or the other.
Go ahead and build what you want, if you survive the crash you can write about it.

righto, I understand all that, not that I,m going to be riding it with racing intentions

next question seeing your the only one putting your 5 cents in the ring, have you ever ridden a solo with a link on it?

I purposely did, for a good long while, {many thousands of klm} and having that link set at 1/2 inch pos trail had no ill effects at any time, both 2 up and by myself which is where the idea for the flex comes from,

I,m thinking if the lead is 1/2 " pos trail and leaning or counter steering turns the bike into corners, no trail will mean moving from leaning into a corner to steering into a corner like a normal outfit would it not

any thing forward of that you,d absolutely be asking for trouble, if not you,d have extremely touchy steering,

be good to hear a few other fellas, ideas,,,,,, shoot my idea down or agree, or move the parameters a bit, I think I,m answering my own ??? but we,ll see what comes of it

I think even at 2.5" of trail one has what might be called "extremely touchy steering".

L.

I didn't kick in as I frankly have dificulties to capture Your intensions.
I am a eye learner. You have a sketch?
All I remember from a test with several bicycles: If there is no trail, or an inversed direction, both were practically unridable.
We talk of many years ago.
One of our employees used to come to work on an accrobatic bycicle. That youngster needed more space on the road then I with my rig.
Perhaps our professionals have more to say.
Sven :O

The only solo with link front end I have ridden was an R26 when I was young. I rode it everywhere and beat the crap out of it but couldn't break it. I didn't know anything about rake or trail back then but it performed well and I had no speed wobble or tank slappers. BMW put Earles forks on everything back then even though they were the inventers of the hydraulic telescopic forks.
BMWs of the 50s and 60s were the best sidecar frames ever on production motorcycles.
I did see a high speed tank slapper on an R-69-S as it came towards me at about 80. It threw the rider and crashed. He lived but with a lot of injuries. That was in 66.

Geof, it took some double reading to catch your idea from down under.
nothing else did Yamaha in 1987 with their parallel front suspension. Take a common 1920tees technic, add ball bearings, hydraulic damper and sell it as a new patent.
(in my eyes a total hoax).
In your case you think about to use the double leaner idea that was used on wooden round / oval track races and refresh it.
Not such a bad idea. Remember all designs start with an idea and get totally over thought when put into real life.
Phelonius / Jim has more experience and real life hands on time the I.
2 points make me doubt. Equilateral triangle located wheels and no trial.
Those old double leaners had their sidecar wheel way back as our fixed modern rigs. And the front wheel had long normal solo bike trail.
Why? Because of stability. Without trail the solo as the leaner become tippy. The slappers on fix rigs at slow speeds come from a fight between trail on the front wheel and toe in on the sidecar wheel. Until above the slapped speed the handle lever of the trial overcomes the s/c toe in force.
In your idea fast you will get back to trial possibly 70-100mm.
The idea with the s/c wheel way into the front I suspect you to get some forces fighting between wheels. S/c wheel trying to countersteer when leaning into a corner. As I understand Jim the trouble comes with some kind of slap (stone,hole) while leaning as you have a lever between tire ground contact point and gravity center plus all wheels joined.
that is supposed to be the reason why the 1920 double leaners and the nowerdays fixed rigs have the s/c wheel close to the back wheel.

I had to jump off my Norton commando at 85kmh/53mph because of slapping from touch down to touch down...How would it feel with a linked double leaner ? Would it catapult me off the side due to much more inertia and lever action???

I do not want to discourage you, but warn you to invest too much time and money into the project.
Keep yourself in the design a door open to review and tweek.

Example a buddy in Germany tweeked 2 1/2 years on a MZ s/c frame until he got it to a perfect point
( his dream was to counter steer the variation in load and get neutral steering in every situation)
The principle was easy to follow. But he could have bought a Beemer/EML rig for the cost of his invention.
Sven

Now we are starting to get some where, thanks,

With the outfit wheel forward so far I was actually looking at running it square with the bike, (no toe in at all), which in my way of the design when the bike lent left or right it would push, pull the s/c wheel into its own geometrical circumference, so as not to be pushing a tyre that is pointing into the bike the opposite way and scrubbing the life out of the Tyre,

As far as tweaking room, that is already in the plan, all mounts will have a large scope of forward and rearward movement, (4 to 6") to start with any way,

Geof, there was even a single track car.
Damn it, go for your dream!!!!!!!!!!!!!!

http://de.wikipedia.org/wiki/Winkler_%28Automarke%29
If I remember right there was a stabilisating giro in the botomn of the vehicle.

All have one thing in common. parallelogram linked paired wheels

The main source of my oldtimer knowledge is
www.oldtimer-markt.de
As marvellous the technical articles are, as scrappy is their internet page and will not show up no details. (looks like they want to see money for to access their achives.
I have several early years piling up in my store room.

A thought; The inner leaning tire(s) runs on a shorter radius, it should lean deeper then, means the parallelogram should become more like a trapezoid link with the wider side up.
As deeper leaning the rig as more progresive should lean the inner wheel

There is nothing worse in this life then not to give your dreams a shot!
Sven 😉

My planned pivots are going to be steering ball joints off a very small car

Horse tracks are often better then our roads. 1,5 - 2million vehicles in a 4,8million people country with roads planed for 200.000 vehicles , tropical high mountain range.....Regards from the people of Gotham.
for pivots I thought of needle or ball bearings. Ball heads are good when you do need sideway liberty, but they wear relatively fast and any gap causes trouble to in multiple joint systems.
in small sideway movements work barrel bearings well.
Sven

Peter Pan , those are some really interesting photos but I wish it gave more information about them.
I haven't spoken German in 50 years but I was able to get through the Winkler paragraph.

Hello Jim,
we become as Old as a cow and continúe to learn. That thought Grandma, her sister in law the only surviving family member out of that generation has not spoken her native Polish since 1945. I bet a couple of weeks and something comes back.
A client never spoke German,only heard it from his Grandfather. With 38 he came to Germany for a post graduation, after 15 days he started to speek. At the age of 68 he recited a full chapter of Wilhelm Busch's Max and Moritz his grandfather used to read for him.
Same for me for in Sweden. I haven't spoken Swedish since 4 years old, but could understand something at the end of my vacations when 18 years old. (I dummy did not use the opportunity to learn it with a good friend).
Its there, just burried and needs to be dug up...
Sven :O