The 6 prototypes
In 1994 the first Double Trolley prototype was made.
For the next 5 years, the Double Trolley was tested by him and many other bass players to find out how to improve every detail of the concept.
In 1999 the last prototype was finished. The Double Trolley had undergone several changes and was now ready to go into production. Have a look at the history of the prototypes:
Prototype no. 1
Made of square steel tubes, this first construction is the basic concept of the Double Trolley as it is today.
The wheel part had no strap attached to it nor locking mechanism on the wheel axle to hold the rear leg of the stool piece.
Prototype no. 2
All dimensions where adjusted on this prototype, and it was made of round tubes. The bigger wheels were selected so that the trolley could roll more easily on the street and up/down stairs.
Hook strap for the endpin
Improved stability of stool
Prototype no. 3
The height is now adjusted by a click mechanism to avoid the uncertainty of the tightening screws on the prototype no. 2.
Click mechanism for locking the height and angle of the stool
Prototype no. 4
To give better support for the side of the bass, the seat was turned around in the trolley configuration.
Click mechanism hidden inside the tube
The seat turned around to better support the bass
Prototype no. 5
The first model in aluminium reduced the overall weight of the Double Trolley.
Lighter aluminium frame
Prototype no. 6
The first prototype built by professional craftsmen. Only small adjustments were made to this prototype before the Double Trolley was put into production.
Solid locking mechanisms
Special fittings between all moving parts
I've been using your stool for almost a year, and I think it's a great contribution to the world of equipment. I love the fact that I can transport the bass without the bass bag on.
It's indeed very comfortable as well.
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