Jan 07

Here goes. I have spent more time today ironing out details of the running cart. I will post a series of images taken from the CAD and describe each:

running cart1

This is a side view….. you can see that the handles for for the runners are connected to the frame via an S and S coupling. The handlebars have bar ends on them where a brake lever could be mounted (to avoid the runaway situation).

The front end of the frame is also connected via an S and S coupling. This way You detach the two halfs of the TriBike, and join on the front end of the running cart.

running cart2This is the isometric view. The casters are 16 inch bicycle wheels. This is a standard size used on kids bikes and recumbents. Tires should be relatively easy to find. The forks that make up the casters are custom, but they attach to the frame using a standard 1-1/8 threadless headset. The casters are also fairly widely spaced to try and lend as much stability as possible.

running cart3This is a rear view of the same.

running cart5Close up showing the S and S coupling in the frame.

running cart6Front view

running cart7Now that all the fundamental geometry is worked out, I changed gears to start addressing some of the other issues that we had discussed.

Jay commented that Caroline had handles on her stationary bike and that they were quite useful for her stability. So handles mounted to the seat rails seemed to make quite a bit of sense.

Also we had talked before about having a safety net in case Carolines feet were to fall from the pedals. This has taken the form of a fabric net attached to a tubular subframe, that is welded to the bottom of the member to which her cranks will be attached.

running cart8Side view with handles and foot restraints

running cart9Another isometric.

There are still some things that need work:

  • Shoulder harness/ chest strap for the seatback.
  • We should discuss this, because there are several things that come into play including cost. We could do a totally custom seatback with lots of support and shoulder straps, but we run the risk of this getting rather expensive if we need to cut a special mould and need to make custom cushions for the seat. I will defer to you guys for this, lets talk it over tomorrow.
  • Chain lines…… we will need chain guides to take the chain under the seat, to the rear drive wheels.
  • Cable routing…… we need to figure out which way the cable is going to go, so that we can plan to have Reid having control of Carolines shifters, and brake in cycling mode, and then transfering the control of the brake to the handlebars in running mode. This is where the cable splitter will come in.
  • Checking the geometry of Jay’s bike with respect to the hitch rack. I think that I will need to go back into that section of the design and make the rack a little more adjustable. It will definitely need to fit Jay’s specialized, but it should also be capable of fitting other frames of the same size.

If there is anything that I am forgetting then please let me know! We didn’t manage to connect today, but lets try to talk tomorrow.

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