Toy Run

Discussion in 'Travelling, Commuting & Safety' started by Fabian, Mar 12, 2014.

  1. Fabian

    Fabian Well-Known Member

    One of my trips to a local rail trail Carriage Cafe to donate and drop off toys for the little boys and girls to play with.




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  2. Fabian

    Fabian Well-Known Member

    But this time i loaded up like never before. The kids thought it was Christmas when i tuned up. Didn't take long before they were recreating car chase scenes straight out of "The Dukes of Hazzard"


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    powerstroke likes this.
  3. powerstroke

    powerstroke Member

    Not the type of 'toy run' I was expecting :D,.. I bet the toys smelt of mixed fuel when you rocked up though. haha.

    cool setup, do you find that the trailer affects your riding at all?
     
  4. Fabian

    Fabian Well-Known Member

    The uni-wheel bicycle trailer does have quirky handling characteristics in tight turns, especially tight U-turns. Having said that, it's far more stable than a two wheeled rigid axle bicycle trailer on rough terrain, hence the reason for it's daily use.
    I need to add that the trailer isn't designed to have large lateral torque loads put through the rear suspension swingarm, even tough it can be set up with panniers, as i have done.
    By design, it is meant to have the main carrying weight loaded into the basket, and to have the heaviest items placed at the lowest point; maintaining a low centre of gravity.

    When you load the heck out of the trailer and create a high centre of gravity on the rear suspension swingarm, it induces strong lateral torque loads when the bicycle rider inputs roll movements through wiggling the handlebars left and right. Typically this happens when applying moderate pedal power through the drive train.

    When this motion is transferred to the bicycle trailer, it causes the trailer connecting fork arms to flex (storing energy) and then the roll motion is transferred to the basket, which transfers roll motion to the swingarm.
    Considering the swingarm is highly weighted, it ends up flexing (and storing energy) because the tall load on the swingarm is resisting roll motion due to a high centre of gravity.

    When the bicycle experiences the next roll motion in the opposite direction, the stored up energy assists the bicycle to accelerate the roll motion, which cause the rider to try and counteract this force.
    Naturally the rider wants to aggressively counter this unexpected roll motion, and in so doing, he rolls the bike with more than normal counter force in the opposite direction. The result of this action causes the trailer connecting fork and swingarm to absorb even more lateral roll motion, which then gets passed back to the bicycle when it rolls in the opposite direction.

    If the rider isn't aware of the quirky dynamics of an excessively loaded uni-wheel bicycle trailer, he/she can get into a lot of trouble very quickly, especially if the trailer sets up a serious oscillation on a fast downhill run, which can build very quickly.

    The solution to prevent excessive trailer oscillation when overloading the trailer swingarm (if a pannier system is fitted), is to keep speed below 30 kilometers per hour (18.5 mph) when travelling downhill with the brakes applied.


    For typical operation with only a light load in the rear swingarm panniers, there are negligible lateral torque loads to cause unwanted oscillation, and in turn this allows you to travel at your desired speed without any undue concern.
     
    powerstroke likes this.