even a tyre lever can nip and puncture a tube........
trick to removing a tyre is to delfate the tyre fully (a schrada valve core remover is handy)
use finger and thumb to unseat the bead of the tyre on both sides then push the tyre inwards to the center of the rim and press the tyre and rim to the floor with your toes...
pull the top of the tyre upwards this should get you a bit of baggy to get the lever in and rim off most wheels i can do without tyre levers this way,,, but some downhill rims and heavy off road tyres can be a pain even with half a dozen levers....
(i used to work in a bike shop) so am happy building bikes from the fame up and even reasonably happy building wheels but in not an expert at that black art
Minimum trail side kit i carry when mountain biking...
Toppeak multi tool with chain link splitter (Very important)
separate spoke key to remove broken spokes
http://www.alpinebikes.com/shop/topeak/ ... ulti-tool/
I have one without spanner as all my bolts are hex
relevant "power links" to bodge a broken chain
http://www.chainreactioncycles.com/sram ... rp-prod871
Pliers type multi tool for holding / bending bits back straight (leatherman blast with bit set is what i carry with a lock knife (handy to safely cut a ...)
Tyre boot patch
pump to suit valve type i like toppeak or crank brothers pumps
t25 torx bit (disc brakes)
spare tube x2
puncture outift
gear cable (can double up as a brake cable on cable brake bikes)