I only just started riding recently, so I don't know what will be good, I am doing my first MTB race tomorrow. I have bought myself two of those CO2 canisters, with the gadget to use with it to inflate my tyres, in case of a puncture. I also bought the puncture repair kit, I think these two will come in handy.

Further on I get some pain in the but and bought myself a nice riding bib short, I hope this will help, any good gadgets to help with this issue??