Should be a really great tour. I did the full* Mawson Trail with a mate in 2010 and we really enjoyed the quet roads and back routes. It's probably wise to get the maps from BikeSA. We just used commercial maps of SA that also showed the trail route quite well, but we had limited ideas about where to camp or anything about the detailed history/geography of the country we passed through.
We took a comprehensive spares and tool kit, but used very little of it - no punctures or major mechanicals on the trail, although mud-clogged mudguards meant I had to remove them and mess about with my light wiring at one stage, then refit a few days later. For the Thorn I'd take my standard tools and spares, probably make sure I have spare gear cables and the BB tool.
What my standard tool kit includes (all packed in a 5"x4"x2" pack and some in my seatbag):
Tools
6" shifting spanner
pliers
2 tyre levers
Topeak Alien multi-tool
8mm spanner
chain tool
8mm allen key
spoke key
Rohloff sprocket remover
screw driver (dual head)
cleaning brush (tootbrush)
puncture repair kit
tyre boot
Spares
gear & brake cables
spokes (inside handlebar)
brake pads
adhesive tape
zip ties (asstd. sizes)
baling wire
hose clamp
steel rod (5 x 110mm)
assorted nuts & bolts
2 tubes
grease tub
chain lube
* we began at Adelaide and finished at Blinman, but actually rode about 70% of the Mawson. Gaps missed were due to - the steep climb up the Mt Lofty's, a few missed turns, too many headwinds and a desire to 'take' the tailwind on the tarmac and cover kilometres, and a couple of sections of wet, 'orrible muddy trails.
If it rains out there
never ride on red clay roads
