My E-bicycle (12 gears rear only, Shimano Deore XT M8100) has no gear indicator. There is totally no clue which gear is currently engaged.

I find this very inconvenient as using the first (smallest) or even second cog sometimes results in a heavy skip when accelerating or uphill. I do not want this happening hence prefer to know at least if one of these two is engaged on anything above.

What would be the minimal modification to add the visual gear indicator? I was thinking about Di2 but this looks like expensive modification aiming to provide much more than just a gear marker. Are there any simpler solutions? Simple googling does not bring me any obvious solutions.

  • 15
    I'd focus more on why the first and second gears are skipping and solve that because they shouldn't be.
    – Andy P
    Commented Apr 21, 2022 at 9:33
  • 6
    Agree with Andy. Most people have a pretty good idea which gear they are in. You can look behind you at the cassette (if you are able to, which riding) to check which gear you are in.
    – Michael
    Commented Apr 21, 2022 at 10:19
  • With my previous E-bike, I was riding on smallest cog mostly all time, me plus engine on max assist are strong enough. But the drivetrain only served about 400 km when used this way.
    – nightrider
    Commented Apr 22, 2022 at 5:44
  • 4
    @nightrider That mode of use will definitely wear the smallest cog down in no time and will cause all sorts of skipping problems. You might want to install a bigger front chainring in order to shift your most used rear cog from the smallest one. Going with a e-bike specific drivetrain might also be an option. Commented Apr 22, 2022 at 7:47
  • @AndyP let me hazard a guess. Riding a bike uphill in the smallest cog (regardless of which chainring). No problems. But soon it gets worn and starts skipping. That is when the problem gets noticed.
    – Vorac
    Commented May 25, 2022 at 14:05

2 Answers 2


There are 12-speed MTB shifter units from Shimano with gear indicators which should be compatible (in terms of cable pull) with the rest of your existing drivetrain. So, acquiring such shifter and replacing the existing one would be the easiest solution.

Searching the net for "12 speed Shimano shifter with indicator" quickly gave me that "Shimano Deore SL-M6100 12-speed Shifter w/ Clamp + Gear Indicator" is something you might need.


  • 3
    Just to complete this answer: if the OP's bike is equipped with an SLX or Deore Shifter, that is is the obvious solution. But if the bike is equipped with XT shifters, there will a loss of functionality: the number of gears that can shifted in one move is a difference between those shifters (4 down/2 up for XT and 3 down/1 up for Deore). Nothing critical though, it's mostly a matter of personal preferences if you can't have both.
    – Rеnаud
    Commented Apr 21, 2022 at 12:05

(EDIT) For some reason I presumed this was about road bike drop-bars. MTB flat bars have other options already covered in other answers.

There exist in-line gear indicators. Shimano had one but they date from the days of gear cables coming straight out of brifters.

enter image description here

These cannot work with under-bartape cable routing, unless you somehow left a little window.

Model: Dura-Ace 7800, 10 speed
Rear SH81102
Front Y6JA98110

Another option is to use a brifter that has a windowed gear view. This is a 3x7, you're unlikely to find this functionality in a 12 speed brifter though maybe some of the smaller brands offer it.

enter image description here

A sub-variant of this might be to put a 12 speed pod shifter with a gear display indicator on your tops, and then simply use the right-hand brifter as a brake lever. Downside, your hand is off the brake while changing gear, so a bit sketchy and not ideal.

If you're all-out DI2, then its possible to add a display to the system, such as the SC-MT800 or the SC-M9050 Exact compatibility between all DI2 parts should be confirmed before purchasing.

enter image description here

Shimano also had a computer system called FLIGHTDECK which did exactly this using a head unit that was wired to special brifters. This one is in the little ring with the rear on the second-to-biggest cog. Suggesting the rider might be doing 38 miles/h going up a hill in 34:25. Or it's staged.

enter image description here

There's a surprising number of brifters out there with FLIGHT DECK sensors inside, but unlikely to be in a 12 speed model.

Lastly, don't bother. You can remember if you're in the big ring or small ring, and with modern shifters its fairly easy to get to the ends. When the shifter won't push any further, you're out of gears.


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