7. I have incorporated two,
sequential 8-speed Cassettes in my design (each with a derailleur).
One is an 8-cog conventional (11-30) cassette on the rear wheel. The
other is a (mid-drive) cassette: it is a full 8-cog MegaRange 11-34.
(I use a jack shaft at the mid-drive location). The mid-drive
cassette is placed on the left side of the bike, mid way between the
front and back wheels. 
The lateral positioning of this
cassette on the jack shaft is in perfect alignment with the single
front (left-side) chain wheel, allowing the use of all 8 speeds on
this cassette with the single front chain wheel. Although I have a
large number of theoretical gear ranges (64), in reality I use (and
need) only 16, evenly-spaced sequential gear ratios, from a low of
about 13 gear inches to moderately high 110 gear inches. No compound
shifting is required, shifting through the entire 16-ratio gear range
can be done under power. I simply twist one grip shift or the other
to achieve a higher gear ratio or a lower ratio - no attention is
required to "know" specifically what gear I am in or what cassette is
being shifted - I simply shift "up" or "down" as conditions require.
The low range allows this machine to climb extremely steep hills
easily (although slowly) under full control.
8. I use two relatively low pressure (40 psi - 65 psi) Primo V-Monster 1.95 inch wide tires. These tires are pretty good for both off-road and on-road applications.
9. The front boom has an adjustable stainless steel tune section that holds the BB. This enables optimum adjustment. The front chain wheel does not have a derailleur as it is not required. The material of the movable boom - stainless steel - allows the front BB section to be quickly and easily removed without any possibility of paint scratches.
10. For car transportation, this design incorporates some very useful features to result in a substantial size reduction if required such as: i) the rear (suspension) triangle including the wheel and chain etc can be removed quickly and intact, (with no tools): the rear wheel "drive" cog (on the right side of the mid-drive jack shaft) does not entrap the rear chain (as would be the case for the Trek, for example); ii) the front boom utilizes adjustable-position stainless steel tube section (containing theBB) does not have a front derailleur, as mentioned above. Now, this setup does not entrap the front chain, which facilitates quick and easy removal of this part for transportation; iii). the entire seat can slide off the bike completely in about 5 seconds via a quick release pin, iv) the ASS Titanium steer tube can be folded back, flush to the bike frame. (Of course, the front wheel can easily be removed). These features would allow the bike to be configured into a very small "package" (along with small separate packages for the removed parts) so as to allow the bike to be transported within the back seat or trunk of an "economy" car, if required !
11. The bike is relatively high off the ground - the seat base is about 31" above the ground surface. (So, I expect that the bike driver/rider would best be 5' 7" or taller). However, the higher seat height provides for excellent stability, especially at low speeds but also at high speeds: the high riding position also allows good off-road ground clearance and stream-fording capabilities! It also has very good "see and be seen" characteristics which provide ease of mind when riding on roads and streets.
In addition. the design (where the BB is a few inches lower than the seat base) eliminates "hot foot" or foot "numbness". There is no crank/front wheel/(foot) interference allowing for very tight, slow-speed maneuverability which greatly assists in climbing steep hills).
12. The construction in TIG-welded Cromoly tubing (but, of course, brazing would be a viable alternative).
This S.U.B. is extremely comfortable and stable to ride under all conditions: it's more fun than driving an S.U.V. - and the gas and pollution considerations of this bike are terrific!
I would mention that Carey Chen of Urbane Cycle in Toronto providedexcellent assistance and advice regarding my efforts on this project. However, he is in no way to be blamed for the final outcome!
More Q & A's with the builder
1) How did you mount the mid drive cassette on the left side ? Did you use a modified freehub ? Same thing on the right side - another freehub or BB ? Did you use a bottom bracket shell at that junction ?
I first removed all of the "internals" of the freehub (and was the left only with just the casing plus the 8 cogs). This was put on my 5/8" threaded jackshaft (left side)and screwed tightly in place. This arrangement meant that the jackshaft and the cassette were then integral.
On the right side of the jackshaft, I welded a 22 cog to a threaded connector and screwed and locked it into place. This resulted in an integral arrangement.
The mid drive derail also seems to be mounted between the mid drive cassette and midshaft drive cog. Does the derail move chain on the casette or drive cog ?
The mid drive derailleur is mounted to a bracket that is tightened in place on the bike frame jackshaft "tube". This derailleur shifts all 8 cogs exactly as it would on the rear wheel.
2) As for front crankset, did you use a regular crank with the pedals secured with loctite or tandem cranks ??
I used conventional cranks - so far no problem regarding loosening. I don't expect to have a problem in this regard and do not plan to use locktight.
3) As for pivoting chainstay, what kind of pushing ? Alum, brass ?
I used conventional brass, lubricant impregnated, sintered bushings. Thesedevices are capable of high loads, at low speeds, with long life and excellent tolerance/precision (actually better side to side tolerance than a roller bearing). Each bushing costs about $2. If you take a look at high end personal exercise machines that are used in fitness clubs, you see that this type of bushing (for weight machines etc) is used almost exclusively.
However, I used sealed precision anti-friction roller bearings for the jackshaft. These are required because very low friction is most important for this application. (Bushings have more friction than roller bearings generally - but this is of no concern regarding the rear suspension pivots)
The jackshaft has virtually no side loads and so I don't want or need bearings with high axial load capability.