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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