Passenger peg mounts

My new bike is an Aprilia RSVR 1000 Factory. It's dead sexxxy, and has more horsepower than I should be trusted with. In fact, it is 131 pounds lighter, and has triple the horsepower of the Sportster that I traded in. Being the "Factory" model, as best as I can tell it was never equipped with any passenger seat or pegs. Normal models would have had a back seat and pegs on the exhaust hangers.
Provided my looks and personality don't get in the way, I thought it might be good to equip my new bike to carry a passenger, just in case I meet some unfortunate young lass who has bad taste in men and decides she'd like to go for a ride.

Basically I'm using a piece of scrap 1/4" aluminum as my stock. The idea was to see if I could squeeze a pair of mounts out of it. Here, it has already been cut in half. It was a bit of a "U" shape. I also had to dodge some existing holes. I pulled the mount dimensions from the exhaust bracket, and just eyeballed the rest.

I clamped the two pieces together, then drilled/tapped a pair of 10-32 holes. With the two cap screws in and tightened I could treat this as a single piece of stock for most of the operations. That would save on layout and machining time.

Alright, alright...my hands were covered in dye-kem and I had a brain fart and forgot to take a few pictures. Basically, I bandsawed close to the lines, then I used parallel bars to line the parts up in the mill to finish the triangle shape. The three holes are piloted too.

Since the pieces were machined together, I was comfortable clamping them in the mill vise this way and removing the screws. Even as little as .001" difference can cause one part to slip. Using a big honker of a mill I bored through and slotted a lightening hole.

Before removing the pieces from the mill, I tapped the pilot holes and ran in a few screws. This way I could keep them matched up during the final shaping. I added the round shape to the lower part of the triangle at this stage.

Separated after shaping on the sander. The holes on top are at their final size. The lower holes are still at the pilot size until I decide what to do with the pegs. The where they are touching is the forward edge, the sharp points will point out to the rear.

I believe when I was talking about cylinder heads I mentioned that I'm not a fan of sandblasting aluminum. Well, the piece that I was using had been sandblasted. This makes getting the dye-kem off a holy terror. I'll likely sand the surfaces to 400 grit on the granite plate. A 400 to 600 grit finish looks good to me on aluminum.

I just need to order a few bits of stuff tomorrow, like an 8mm tap and die so that I can make the stand offs to tie these up to the frame. The hard part is done, just a little turning to do now. I need more days like today, I knocked these out in about two hours.