To downshift without using your brakes, simply let off the gas and wait until your speed decreases.

减挡不用刹车，只是抬起加速器踏板，等待速度下降。

youdao

Dog teams are able to run without snow by using wheeled rigs, but ice makes underfoot conditions treacherous for the dogs and stops the sled's brakes working properly.

BBC: Aviemore dog sled race cancelled over safety concerns