Riding a bike is great exercise.

骑自行车是很好的锻炼。

《柯林斯英汉双解大词典》

Look at me. I'm riding a bike!

看我！我正在骑脚踏车耶！

youdao

Riding a bike with only one wheel is a balancing act—that's why unicycles are used in the circus.

骑着只有一个轮子的自行车是一种平衡表演——这就是为什么独轮车被用于马戏团的原因。

youdao

The mayor hopes to make London one of the greatest cycling cities in the world, even so,riding a bike through the capital has its challenges.

VOA: standard.2010.07.30

Well, there's a lot of variety. There's different trails for walking and bike riding

嗯，很多呢。有不同的道路供步行和骑车。

激情生活 - SpeakingMax英语口语达人

Riding a bike is simply the cheapest and most convenient form of mechanized transport.

WSJ: An Urban Cyclist's Criteria

Marcos was riding a bike in Coronation Road, Crosby, on 15 July when he was attacked.

BBC: Marcos Ringle attack in Crosby: McCaig brothers jailed

Riding a bike in New York City is becoming a sublime experience, but you might be missing it.

WSJ: Jason Gay: Cyclists, Can You Hear Me Now?