However you decide to carry your kit its better to have it and not need it than need it and not have it. A little bit of thought and preparation can save a lots of time and embarrassment down the line. Having a well set up and serviced bike with good quality tyres will save you the majority of repairs. Even if you are confident of your bike its best to carry a minimal repair kit just in case. Punctures are a part of cycling and once you get better a repairs are really just a minor delay.
Hope this gives you some good info to keep you cycling when the repair gremlins strike.
“Life is like riding a bicycle. To keep your balance, you must keep moving.” -Albert Einstein
