A bicycle mechanism that moves the chain out and up, allowing it to shift to different cogs.
More example sentences
- The other side of the rollers will now contact the gears, and the derailleurs will now be laterally bending the chain the opposite direction.
- Then coat your bike's chain, derailleurs and pedals with a light lubricant.
- My front derailleur and chain rings were so full of mud I couldn't change gears, so I was stuck pedalling in the big chain ring.
1930s: from French, from dérailler 'derail'.
Definition of derailleur in:
- The British & World English dictionary