Wheels!

When the rims arrived, both were unpainted aluminum. Since this bike will not have caliper brakes (discs for me), I had them painted. The overall color scheme is red, white, and black. White powder coat was applied by a local shop with very nice results. Makes me want to paint my other bikes' wheels. 

I had the rear wheel laced at my local bike shop. Short spokes (I cut commercially purchased spokes and rethreaded them) go at crazy angles to the hub. I'm also a complete novice at building wheels. So...I chose the lace the big wheel myself and learn. After A LOT of online research and some guessing, I selected a 6 cross lacing pattern. Compare that to a typical 3 cross for regular bikes. It took around 3 hours to lace all 64 spokes and get it initially true. It was so nice to finally have both wheels. 

Front and rear. big and small. 

Spokes

It has been several months since my last post, but I've been busy with the project. I tried to find long spokes online, but none were available (www.unicycle.uk.com now has them).  Borrowing an Excel spoke length calculator, my 48" rim needed 560mm spokes. That's about twice the length of what you can find for sale. So, I had some tooling made and fabricated my own. Here are some photos. 

I purchased a box of straight 2mm stainless wire that was a few inches longer than the finished spokes. 

The first tool is a bend fixture to make the hub-end bend. 

A rubber mallet quickly makes the bend. 

Bent with the required extension. 

The next tool is a head forming tool. This is one half of the tool with the bent spoke inserted. 

Both halves of the tool clamped together in a vise. 

Heat the stub with an acetylene torch. The next step is to whack the forming tool with a hammer. 

Side view showing the formed head. 

Finish the straight end with a Hozan spoke threader. I learned to take it slowly even with the drill. Double-threading resulted when driving it fast. 

64 spokes later, I was ready to lace the wheel. 

Hub Explosion

Before assembling the new hub, I took a photo of all of the parts (both old and new).  Here's the "new" exploded view.

Finished Hub

It took several weeks and the machine shop found a few errors in my drawings, but the two custom hub parts are complete. Here's a shot of the plain hub body next to the purchased hub. It's huge!

A few days later, they completed the axle and anodized the aluminum body. With the help of a small press to seat the bearings, I had a fully functional 175mm free hub. Action is smooth and everything fits so far. 

Here comes the hub!

Just dropped of the hub drawings to be machined. Hope to have them done in a week or two. 

Next step is fabricating the spokes. I'm going to test several options for forming the head and bending the shaft. 

Front Hub - Build from Scratch

I'm building the front hub from scratch. It will be substantially based on the Nimbus drift trike hub, just resized for the application. It took some time to get through the rusty parts of my 3D CAD skills and make a complete model of the hub body and axle. Below is a really cool "photo" of the hub body next to the original part. This comes from eDrawings on iOS. After modeling the part, you can use their augmented reality feature to represent the part in the real world. As you can see, it is much larger than the original. 

Once complete, I will have it anodized to match whatever color scheme I choose for the bike. 

Front Hub - Modify or Build New?

My first approach to making the hub wide enough was to modify it. It needed to grow in width and the number of spoke holes needed to increase. The width has to increase by 2-4 inches (50-100mm). I envisioned parting the existing hub and using a tube to stretch it. The tube was to be welded to the hub pieces. The spoke holes required a different type of added part, the spoke ring donut. After machining the existing old flange down below the spoke holes, a new flange ring would be welded along the perimeter. The rendering below shows original hub pieces (gray) and the new pieces (red).  

I'm sure this would work, but a local machinist suggested that I would do better to make a new hub from scratch.