I just bought a new bicycle and I just read and watched some videos of how mountain bike gears work.

I noticed that the bike is a triple but the left gear shifter has more combinations than 3 (like the ones I saw in the videos). If I am not mistaken, there are the same amount of combinations as there are on the right gear shifter (something like 8).

Can someone explain how this works?


  • 2
    If you search for "trimming" here, you'll find why that is.
    – Batman
    Nov 4, 2016 at 19:39
  • It varies with the type/brand/model of shifter, but with my brifters the left steps 3 steps when you FULLY operate the lever, but can be made to go one or two steps with a smaller movement. This lets you "trim" the front derailer position based on the rear sprocket chosen and the resulting "chain angle". Nov 4, 2016 at 20:57
  • I wish I had trim on my triple - you're lucky! clatter-clatter-clatter
    – Criggie
    Nov 4, 2016 at 23:48
  • Is it a gripshift with micro indexing? Nov 5, 2016 at 0:04

1 Answer 1


Sounds like a friction front gripshifter with a "Micro-Adjust" shifter. As mentioned in the comments, that will let you "trim" the shifting a bit. As you change gears in the rear gears, the chain moves a little side to side, and may rub the front derailleur. That shifter lets you move the front derailleur cage a little bit to alleviate that chain rub.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.