Jan 03

Lead Bike Rack

By Graham Uncategorized Comments Off

The challenge with the bike rack is actually going to be to figure out the rear hub. We are going to need a tandem hub with a straight through axle, We need this to be sure that it will accept the load, and also so that we can extend the axle to accept the rack. I would recommend the DT Swiss 540 Tandem hub, which is available through many distributors including QBP.

Using the McMaster ball, and the model of a rear hub, I have constructed the geometry for a rack to hitch the lead and the trail bike together:






hitch6Assuming that we can extend the hub axle by 3/4 inches on both sides, I think that this rack should work to join the 2 bikes together, without interfering with foot clearance for the rider of the lead bike.

Let me know what you think.

On another note, I am aware that I am running behind schedule, with this design. I would like to try and push through this week, so that George Reynolds can start the fabrication phase without leaving you guys in the lurch for your May ride. I should be able to dedicate myself to this project full time until January 9th if needed……. after that point production of the 2010 handcycle is going to be underway, and my time will become much more limited.

Please let me know if you have any feedback coments or concerns.

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Dec 18

foot clearanceThis study tracks the path of Carolines foot to make sure that it has clearance throughout its range of motion. In particular I wanted to make sure that there was plenty of clearance with the ground. I was concerned that there might not be enough space to include a safety strap under her pedals.

I modeled Carolines feet, because with shoes they are bigger than Reid’s

Here are some more images showing the position of the bottom bracket. including the clamp to attach it to the main frame.

foot clearance2foot clearance3foot clearance4foot clearance5foot clearance6Next steps are to work on the hitch mechanism with the lead bike. As well as the coupling system to turn Caroline’s half into the running cart.

I have to go back to Palm springs tomorrow. Once you guys take a look at this we could talk some time tomorrow. I will be driving back around 4 California time……. I would be available in the car, or if that is not convenient then I could make time earlier in the day.

At this point we are entering the detailed design phase. So we need to make sure that we are happy with the seating geometry so far and overall frame style.

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