I Just Got This Bucket Together

Two successful road tests. Two successful water tests. But we had a problem.  The wheels needed to be lowered 12 inches but we couldn’t do that with the current suspension system. The top of the raft that we selected for flotation clears the axle of a 26 inch wheel. Switching from 20 to 26 inch wheels would allow us to mount the raft completely under the truss frame,  keeping all the machinery out of the water. 

Can I get a lift?

I had just got this bucket together and now I had to make major changes. It took two weeks to come up with a game plan. We were running short on time so reusing most of the existing work at the front end was our first requirement. I first tried to design something closer to a traditional vehicle suspension. 

The idea was that we would be able to adjust the ride height during the race. With the start of the race looming, I realized that the idea was too complex to accomplish in the time we had left. We decided instead to keep the suspension static, but relocate the axle and differential below the truss frame.  We designed the idea around a steel box beam that would support the main truss. We also added ledges just below the axle for the pontoons, but also for more structural support.

Using the 26 inch wheels also required us to widen the wheelbase by 12 inches. The larger wheels interfered with pedaling while turning, so they had to be moved out for clearance. We decided to make it out of steel, because it’s faster (and easier) to weld–but it’s sooo heavy. Some quick stress analysis confirmed the basics of the idea. 

We got to work fabricating. Caroline and I welded all the U-shaped legs onto the the box beam. Then we welded together the lower knuckle support brackets and pontoon ledges. 

I used the original knuckles to position all the pieces for welding. 

After painting it, I mount new front end.

Wheels on the Falcon go round and round

Switching to new wheels also required modifying new bicycle hubs. Clevis pin holes had to be precisely placed to work with the existing CV axles. However, we discovered that they were too thin to completely hollow out. Instead, we only hollowed out one side then turned down the mounting bolts to fit the hub’s existing diameter. It required some creative holding to lock it down, but it worked great.

I handed off the hubs to Steve who then rebuilt the 26 inch front wheels in Lowell Makes’ Bike Shop.

While Steve worked on those, I rerouted and reattached the chain from the Hyperdrive to the differential. 

Once Steve was done with the wheels, I mounted them onto the Falcon!

Now we just have to reattach the steering linkages to the front wheels. To upgrade the front end, we had and take the wheel from the rear end, because of course! This sounds worse than it is, since we were already rebuilding the rear end. 

This task is not as involved as the front end, but there is still work to do back there. Time marches on.