Seat
This was my first attempt at a mechanism to hold the
seat to the bike frame. It was a piece of square tube the was
welded 90 degrees to a round tube and was part of an exercise machine. I cut
the round tube down the middle to make the half circle that would mate to the
bike’s top tube and cut the square tube so there was only about 2 inches
left as shown in the pic. I drilled a hole in each side then brazed a tube
between the holes on the inside of the square. A bolt could be passed through
and tightened down without fearing the collapse of the block. The oversized
Axion seat base fit snuggly down over this using a 2.5” long 3/8”
bolt. At first those cheap wormscrew clamps were used
but they would strip before they would get a tight enough grip. Found some
excellent T-Bolt band clamps on Ebay. These babies work!
Here’s a two-for shot.
First, the seat mounting is pretty much
the same idea as before but this time I split a bicycle head tube length-wise
and left 2 or 3” of the top and down tube in place. The top tube bit is
where I plan to fabricate the remote steering pivot. The down tube as you see
is the seat mounting point. A second tube which had an OD matching the ID of
this tube was tapped down inside and both welded together around the top edge.
This was just to give it a little more sidewall strength before drilling the
bolt hole. No, I don’t ride with just one clamp. The front clamp was
moved out of the way for the pic.
Second, the bracket attached to the hard
shell seat is nothing more than a heavy duty caster mount. The bolts are
counter-sunk through the top of the seat and covered with padding so they
won’t be felt by the rider. This piece is stout.
I had to clamp the edges in a vise and tap the bracket
with a hammer to bent them slightly to form to the
curve of the seat. The price of the caster was about $6.
Another
clamping idea came about when I was trying to figure out how to attach a swingarm on the back of an existing frame. A stem for a 1-1/8” threadless
fork did the trick as shown in the pic to the left. If you have a 1-1/8”
or 1-1/4” top tube find a threadless stem to
match the dia. Of course you would have to slide it on the top tube before
welding. The head tube end of it doesn’t come apart like the handlebar
side. Hbar clamp can be used to hold the crossbar
found in most all mesh recumbent seats.
