Hmmm,
It all depends on what you are trying to achieve....
for example I am a track sprinter, that's all I care about, so I do few or no "intervals" by which I mean any limited-recovery (sub 10min between efforts) work, most of my efforts are what I call repetitions, with full recovery between each. This sort of workout is not hell of a relevant for anyone other than a track sprint specialist. Road sprinters (for example) hardly ever have to go from super low speeds to flat-out, and they can select their gears- so standing starts have less value for a road sprinter, longer sprints are of more value, and you will win races going from 55km/h up to 60km/h (say) over 25s. Because of gearing issues, most road sprints AFAIK do not involve 140rpm spinning....
1) My back end keeps skipping about 5-10 revs into a sprint. Any solutions?
As above, this is a weight distribution issue- modify where you hold the bars or move your ass back a bit, using a different stem if necesary- there is some fitting philosphy which uses centre of mass as a criterion for the length of the top tube , try googling that
2) Should one start off in a high gear and low cadence then get faster or keep shifting for a constant cadence?
As above, depend what is likely to be useful when you race- a little flexibilty in being able to sprint at various rpms is useful for anyone, even road riders
3) How much should the bike be pendulum-ed from side to side?
Highly variable between riders, from a standing start the bike must be fairly upright and still for around the first 10 pedal revs, then you can start rocking and rolling a bit.... great info (some very tech!) on the fixed gear fever website under the coaching tab- both for sprint standing start as well as pursuit (slightly more steady) starts
4) I've done 3x standing start interval rides; when will my shoulders stop hurting!?!
Pain is weakness leaving the body-seriously that's a great sign that you're really trying- I know my standfing starts are getting good when my wrist extensors are murderously sore two days after s. starts
5) Any intervals you can recommend?
Mix long with short sprints, do some repeats, some intervals, some low rev starts and some from 80 rpm or so you need to do it all..... dare I say a coach could help?
Good luck,
Scherrit.
The Bike Whisperer - experienced, qualified, friendly - helping you achieve your cycling goals