Shimano XT Thumb Shifters

Shimano XT Thumb Shifters are perhaps the finest bicycle component ever engineered. For the bicycle tourist riding a mountain bike style bar Shimano XT Thumb Shifters offer the perfect blend of functionality, reliability, adaptability, and ease of use.

My love of Shimano XT Thumb Shifters developed as a bike wrench in the late 80’s. Under the bar trigger shifters were being spec’d on mountain bikes of all makes and models. They were cheap, difficult to tune, and every bike we sold was repeatedly brought back to the shop for tune ups. Most of our customers complained about the trigger shifters whenever they were in the shop.

I favor Shimano XT Thumb Shifters over trigger, dual levers, bar end and/or twist-shifters and any other type of shifters you may suggest.


User Thomas S. shows us a complete breakdown of ML-732’s here. I have never broken down a set this far. I have found them to be the lowest maintenance part of my drivetrain

I still run an 8 cog cassette and I love my Shimano XT Thumb Shifters with the phantom click. I am sure there is a market for a new set of thumbies, perhaps paired with XTR level components that people would buy.

Thumbies ability to switch to friction mode is a must for anyone who counts on their bike to get them over long distances. They served me well on three cross country rides as well. The simplicity of good design. The click-click-clicking sound that truly only a minimalist could appreciate. It tunes easy. It is reliable. It is easy to work and it keeps my hands where they need to be.

Shimano xt thumb shifters

They were part of the Deore XT 2 grouppo and carried the SL-M732 part number.

Shimano XT Thumb Shifters service instructions

shimano xt thumb shifters

shimano xt thumb shifters

shimano xt thumb shifters

shimano xt thumb shifters

4 Replies to “Shimano XT Thumb Shifters”

  1. I run these with the XT long cage rear derailleur on an 8 spd cluster and in the last few years the shifting has gotten unreliable in the middle of the range. Tuning for exact downshifts mis-positions the derailleur for upshifts, and vice-versa. I’ve made sure my cable housings are in good shape and well-seated and the derailleur hanger is true. The shifter barrel doesn’t have any play on its pivot.

    How can I get my old crisp XT shifting back? How can I tell if perhaps the detents in the shifter itself are worn out or if the derailleur has developed too much play in its pivot points?

    1. I did a rebuild guide a couple of years ago on the RetroBike forum:

      Relatively simple, apart from refitting the sprung top plate (that holds the indexing plate). Could be that indexing plate is worn and/or a strip-down, regrease and tightening would sharpen them back up.

      Despite the claim above I think the XTs are slightly weaker and sloppy compared to the Deore IIs. The XT upgrade of a ball bearing is superficial and on the one pictured above it has distorted anyway. Same with most of the XT group to be honest, any upgrades and weight loss are tiny for the huge new/used price increase over Deore II/DX.

      Personal favourites are the Mountain LX thumbshifters which have a longer lever and lighter/crisper action. Sadly you have to find even rarer Exage Trial mounts to use them standalone.

  2. Steve – happy that there is another thumb shifter addict out there and sorry you are having issues.

    Can you eliminate chain and cassette wear from the equation?

    Look at this link for a complete breakdown of the thumb shifter. I don’t know if it will help but you may be able to self service and correct this yourself.

    As far as I know there are no replacement parts or service on these antique but highly functional components. I would weigh breaking them down and trying to service yourself vs. heading off to eBay and buying a new set. Maybe doing both.

    Let me know how it goes….there is always friction mode 🙂

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