Hub center design and machining

With the Chassis well underway i design and machine the Hub center parts. It all needs to fit into a modified Marvic magnesium wheel. Parts include:
-Axle
-Axle pinch blocks, these will be welded onto the front swing arm.
-Kingpin, at 10:00
-Inner hub at 2:00
-Low profile bearing at 4:00, we need two of these, they are $200.00 a piece. 2.625 i.d. with a .312 x .312 cross section
-The bearings at 7:00 are to support the kingpin within the inner hub.
-Not shown is the outer hub which will spin on the low profile bearings. It will be epoxied into the modified wheel.



Inner hub with kingpin assembled onto the axle.


The Marvic wheel having its center milled and then bored to accept the outer hub.

The nearly complete assembly. A circular plate on either side of the wheel sandwich the outer hub and do double duty as they will also preload the bearings. The holes in the plates allow 4mm bolts to secure the plates to the outer hub and to secure the plates to the wheel as I do not fully trust the epoxy. The 5 visible holes on the inner hub are for the attachment of a steering arm. There will be a steering arm on the left side as well.

Swingarm and chassis.

The rear swingarm bolted into the rear uprights which represent the starting point of the main chassis fabrication.



Close up of the rear swingarm pivot. Plastic Nyliners are used for pivot bearings.


A fox Air shock from a mountain bike should do just fine. 1.25 inches of travel front and rear.


The chassis has come togethor. the bored holes in the front are for the front swingarm pivot.

Concept:

We did a quick mock up with the totalled RS125. It is quickly apparent that a hub center steered vehicle will help keep the frontal area to a minimum. A standard fork and triple clamp will force the riders head up a another 2-3 inches creating greater frontal area and additional drag.


Chris and I start building the frame. I machine all the hard connection points and Chris joins all those points with tubing.


We are feeling the need for speed and let
speedy building techniques override aesthetic
decisions. It yields a product slightly agricultural
but gets the job done.

2006

As many of us new to land speed racing rookies now say "This all began after watching the film, The Worlds Fastest Indian." This film documents a mans quest for speed and sparked memories of a visit to the museum of Science and Industry in Chicago as a nine year old where I viewed "The Blue Flame" jet car after reading about it in Popular Mechanics. The Blue Flame owned the outright land speed record of 622MPH set at Bonneville in 1970. This was more than an incredibly exotic object, it represented romantic motor sport adventure. So it was now time to start planning an our own adventure to the infamous Bonneville Salt Flats.

A friend, Chris Bernard of Puffin Engineering, had mentioned going to Bonneville with a race car he had built but we were such bike nuts it seemed best to do this on a motorcycle. Another certifiable bike nut and friend, Dwight, had just survived a wreck on his Honda RS125cc grand prix bike destroying everything but the motor. The AMA 125cc records looked achievable so off we went with Dwight's motor. We set our sites on the Special Construction class as Chris and I both own machine/metal fabrication shops and figured building it from scratch was the best idea. Given we had four months until the BUBS speed trials, maybe it wasn't. Onward.