Saturday, July 5, 2014

Re-modified Don's delta trike (sigh)

 July 4th, 2014 - the owner (Don) was complaining that the main tube was canted about 2 degrees to the right.  So today we dismantled it.  We removed the rack, wheels and axles, the seat, and disconnected the shifting cable.  We inverted the frame, I was going to use a hacksaw, but instead used the cutting wheel on the 4-1/2" hand grinder.  I cut from the bottom at the point where the main tube connects with the rear unit ... but not quite all the way through ... just short of the top re-enforcing plate. Cut the support tubes from the seat back tube, and cut off the seat mount unit.  So, with the main tube only connected to the rear unit by the top re-enforcing plate, put it upside down in a vise, checked for level on the main tube,  then torqued (twisted) the rear unit until it was level with the main tube.  That re-enforcing plate is pretty tough (1/8" thick) and with Don pushing up on one side while I applied my weight pushing down on the other side.  It took us 3 attempts before we finally moved it enough to the proper position.  Then welded it back together.  Adjusted and welded back on the seat tube support tubes, welded on a new seat mount configuration (with a little more rearward angle to the seat), and welded on a roller to support the bottom return part of the chain so it doesn't hang down and swing back and forth.  Bolted the wheels, axles, and cargo rack back on.  Then we cable-tied a basket to the rear cargo rack for the owner to put groceries in when he goes shopping ... or books when he goes to the library.  And finally hooked back up the shifter cable after making an alignment adjustment to the rear derailleur mount.

I'm talking about being exhausted!

The above photo is the re-completed modified delta trike ...

This is the lower chain roller ... when forward pressure is placed on the pedals, the top part of the chain sits about an inch (2.5 cm) above the roller unit.  There is a shield over the roller to keep the chain from hopping off the roller (had that problem before on another recumbent that I built).

Looking at the area where all the work was concentrated today.  Right in the middle you can see the silver "top re-enforcing plate" in front of the rack (the plate I didn't cut through).  This is where all the critical action took place.

In this photo, there is a better view of the seat mount (above the basket) ... and you can see the chain roller down in front of the seat.

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