bicycle与bike意思相同，作名词都有“自行车；脚踏车”的意思，作动词有“骑自行车”的意思，二者拼写不同。另外bicycle较为书面，较正式，bike较口语化一些。
bicycle与bike的用法
1.I got there by bicycle.
I got there by bike.
我骑脚踏车去那儿。
2.It only takes eight minutes by bicycle to the dancing class.
It only takes eight minutes by bike to the dancing class.
骑自行车去上有舞蹈课只需要八分钟。
3.You can go there either by bicycle or on foot.
You can go there either by bike or on foot.
你要么骑车要么步行去那里。
4.The man bumped me off the bicycle.
The man bumped me off the bike.
那人把我从自行车上撞下来。
5.I'm going by bike, and you may go by bus.
I'm going by bicycle, and you may go by bus.
我呢，骑自行车去，你们呢，坐汽车去。