wheel horse

1. Sometimes a wheel was off the ground, it seemed, for many yards; sometimes a stone was sent spinning over the hedge, and flinty sparks from the horse's hoofs outshone the daylight.
   有时候，马车有一个轮子离开了地面，好像跑出去好几码远；有时候，马车又带起一块石子，旋转着飞过树篱；马蹄踏在燧石上，火花飞溅出来，比日光还亮。
2. Gravel has a wonderful habit of sending your back wheel flying off into a random direction like a bucking horse, while sand just brings the entire bike – and rider – to a halt.
   碎石有一个奇妙的特点&它会使你的自行车后轮突然转到别的方向，就像突然跃起的马一样。然而沙子只会让整辆车子和骑手停下来。

noun

1. a draft horse harnessed behind others and nearest the wheels of a vehicle

   Synonym:    wheeler