I am fine here and I hope you are also fine. I am writing this letter to thank you for gifting me a cycle on ________(ocassion). I am glad that you remembered that I always wanted that bicycle, and it is so beautiful and fun to ride. I was very surprised and delighted on receiving it.
Now, I can finally ________ (commute easily/exercise daily/participate in the cycling competition/other). I was overwhelmed by your great affection towards me, please be there to support me always. Once again, thank you for this lovely gift.
Hope to meet you soon. Pay my regards to mom and dad.