*puts mother hat on*
Tell her the truth, go to her and say "Mum, I had a bit of an incident with the new tyres on my bike and I got a puncture already, I'm really sorry about it and I do realise how much time and money it takes to get it fixed, I'm such a clutz! but I promise I'll pay for the repair and I'll wash/load the dishes every day for a week as proof that I am really sorry and being mature about it"
Hopefully you can be sincere enough to pull it off and she'll respect you for being honest and responsible 😉
Hopefully :lol:
