Any alternative use for old mountain bike tyres and inner tube?
Tubes are extremely flammable.
I carry a tiny pouch of cut in stripes rubber when backpacking, if things get ugly and I need to light a fire in damp/wet conditions.
Seriously - they burn like gunpowder.
Edit: Reality Check.
Yesterday morning I wanted to start a fire after a light rain. I picked up dry tree branches (from trees, not the ground). Then put about 5cm of tube cut into thin stripes underneath. Touched them with a lighter and was cooking breakfast right away.