Comments on: Brudeli 625L Tilting 3 Wheeler

By: Dave

Dave — Tue, 05 May 2009 17:03:49 +0000

To clarify the physics of bike steering –

Once they are moving at enough speed for the rider to raise his/her legs off the floor, all bikes powered pedal and push along scooters steer by leaning. However at low speeds this is masked by the steering need to maintain balance. To balance on a bike you simply move the tyre contact patch under the bike and rider’s centre of gravity. At low speeds it takes longer for the wheel to get into the right position so we tend to move along with a slight weave.

To turn a bike the centre of gravity has to be put to one side of the tyre contact patch. So to turn right we momentarily move the front wheel to the left. This causes the bike to lean and steer to the right. When we have the right amount of steering we stop applying any force to the handlebars and the bike simply goes around the bend. Cornering forces counteract the mass of the bike that’s displaced to the side of the C of G. To exit the corner we have to apply a steering force the opposite way bringing the bike back to vertical.

To keep the bike turning there will always be a slight steering angle on the handlebars, but compare this to a car and you can see its really quite a small amount of actual steering and on a constant curve the rider will not be applying any force to the bars until he wants to go straight again or turn tighter.

Many riders believe they use their body to steer the bike but in fact that are unconciously putting mopre force on the inside handlebar. Most will ride faster and smoother when they fully understand the actual dynamics. Hanging off the bike and knee sliding is all about getting more cornering speed for the same lean angle. Its worthwile on a lightweight racer, but (apart from the safety issues) heavy road bikes benfit much less as the rider has relatively less mass to influence the bike.

Hope this helps.

By: James Bowman

James Bowman — Thu, 06 Nov 2008 17:08:38 +0000

Kilibreaux Thanks for the detailed description of the dynamics of a motorcycle, my only confusion is when ever I turn right I have my forks pointed right, after of course a slight left moton to induce lean. So while cornering nearer limits should I be turning further in the direction of the turn or the opposite to maintain or tighten the radius of my turn.

I feel these vehicles give us the best attributes of a four and two wheeled vehicle with the least comprimise.

I also realize this is an old post but hopefully you might see it.

By: Mike

Mike — Thu, 31 May 2007 01:44:42 +0000

I think that this is the best thing to come out in years. I have always been a fan of three wheelers and i have tried to do this but without the proper facilities it is kinda hard. I do think that this design will seriously take off and especially if it is road legal people will ride these things around everywhere I know I sure would. I definatly support this and would definatly buy one whether it is road legal or not I just hope that you guys can keep the price down.

By: Kilibreaux

Kilibreaux — Thu, 17 May 2007 09:32:22 +0000

The concept is sound, and in practical application offers many advantages over traditional motorcycles. On a motorcycle, the ability to take curves fast is highly dependent on external factors, not the least of which are road conditions, and if one loses traction either front or rear, the consequences are usually a crash. With the 3-wheel reverse delta design, “sport” riders can attack corners with gusto because a loss of rear tire adhesion results in a typical multi-wheel slip which is most often recoverable with simple power reduction…the main point being the 3-wheel design cannot slide down onto its side.
As for the mistaken notion that the large floorboards are necessary to enable the rider to “get the thing to lean”, this sadly illustrates there are still all too many two-wheel riders who don’t know what actually makes the vehicle lean. All 2-wheel bikes lean by action of a slight offsetting of the front wheel AWAY from the direction of turn (at speeds above 18mph or so). When the forks are turned, the front wheel doesn’t actually rotate around the center of its contact patch, but around an imaginary point located some distance behind causing the front wheel to DISPLACE laterally away from the bike’s centerline. At speeds over 18mph, the bikes inertia–along it’s centerline, is now slightly inside the front wheel contact patch, and this combined with the phenomenon of gyroscopic precession effect on the wheels causes the bike to “lean” AWAY from the direction to which the front wheel is displaced…hence the term “counter-steering”, and the technique taught in all motorcycle riding courses where students are taught to push the inside bar slightly (more pressure), thus making the bike lean into the curve. We can thank engineers for bikes so well designed many inexperienced and untrained riders THINK they are making bikes lean by weight-shifting, but the fallacy of this becomes all too evident when riders push faster through curves and exceed the bike’s engineered in “willingness” to lean, and then MUST apply a conscious, deliberate countersteer force to induce additional lean…which they do not since they don’t understand the concept, and eventually end up in a ditch somewhere.
Since the Brudeli leans as does a conventional 2-wheeler, it too must use the same physics to induce said lean…a slight countersteer pressure creating a slight departure of the centerline mass away from center, thus causing it to lean…which has nothing to do with floorboards OR pegs.
“Leaning off” allows bikes to negotiate smaller radius curves with LESS bike lean because the rider has displaced his/her mass which means the machine needs less lean.
Anyone who doubts the physics of how and why motorcycles lean need only modifiy their personal 2-wheeler by rigidly locking the front forks so they cannot move, accelerate to any speed over 18mph, then get busy “leaning” their body to induce it to lean and turn…after they crash, they’ll have empirical proof.
The Brudeli design has the potential to markedly revolutionalize motorcycling everywhere, because it offers the same sense of freedom and handling of a 2-wheeler with the far greater stability of 3. I’d love to see the concept extended into a wider market. As for gaining road certification I see no reason it cannot considering that if 2-wheel motorcycles were invented today they would NEVER achieve street licensable status due to being–by design, inherently unstable and dangerous. It is only because we have had motorcycles around in their current configuration for over a century that they are still allowed on the general roadway.
I’d like to see Brudeli enter into licensure of their design to Japanese and Korean companies, and bring such machines to market at a competitive price. $25-$30K is a LOT of money to shell out for a modified dual-sport, and that will confine the Brudeli to a VERY special market. What is needed is to drop the foolish marketing pretense that it NEEDS to cost so much more because of some special wizardry, and get it and others like it on dealer showrooms at prices competitive enough to induce not only new buyers who would have never considered riding a 2-wheeler, but also EXPERIENCED riders who feel perfectly comfortable on 2-wheels, and so will not see any practical reason to pony-up a considerable premium to buy the Brudeli when for the same money they could be riding pretty much ANY 2-wheeler.
So Brudeli needs to drop the KTM platform which is already overpriced compared to Japanese makes that are better, then get the Japanese and Koreans interested in building a line of “leansters”…specifically powerful highway cruisers and sport styles…they’ll make a LOT more money, and their idea will change the future…otherwise it will suffer lackluster sales and eventually fade into the dustbin of history–a GREAT idea and superb design that failed due to flawed thinking in how to market it.

By: Arild

Arild — Tue, 06 Mar 2007 09:54:46 +0000

You don’t need the “floor panels” to tilt or change direction. (It’s me on the photo above). Actually we had the fastest lap times when we used the normal fotpegs. That means we use it just like a normal bike.
The “panels” is allways paralell to the ground so you use them while drifting. And drifting is great with this machine.