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9 Speed Thumb Shifter Conversion

15:27 11th February 2003 by Bikemagic
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I’ve used thumb shifters on my commuting bike for years now and have always appreciated the simplicity of them. In fact so much so, that last year I finally decided to ‘upgrade’ my Marin Quake to use thumb shifters instead of the XTR Rapidfire STI’s that were already on it.

This was to give me two advantages – the first was the opportunity to move into the now (nearly) standard 9 speed arena, and the second to be able to fit my Hope C2 disks onto the Quake – something I’d been wanting to do for longer than I can remember. Using the equipment I had chosen also gave me the chance to keep the XTR quality but at a much lower price than XTR 9 speed would have cost.

The basis of the shifters were Shimano Dura-Ace bar end shifters as used on road & tourer drop handle bars. I managed to pick up a pair from St. John Street Cycles in Bridgewater (s.com@www.sjscycles.com) for £49.99 – almost half the price of XTR shifter pods.

The next problem was trying to fit them. I’d played around with CAD for a little while, trying to design a mount for them, but everything I came up with was more than a little bit chunky and I’d have the hassle of paying someone to make it up for me. But then a flash of inspiration struck: Bar ends already have clamps on them, so why not use some old ones that were kicking around the garage?


All that was required was to shorten the bar ends quite drastically and drill a hole through them. Experimentation finally led me to discover that 25mm was about the right length for the bar end, and a 10mm hole put horizontally through the middle of the remaining stump was more than enough to hold the shifter.

Fitting the shifters themselves was quite easy. Removing the expander that normally fits inside the handlebar gives you a handy 10mm bolt that will fit nicely through the hole in the bar end and allows the shifter to clamp tightly to the mount. This fitting also allows the user to adjust the angle of the shifters almost infinitely, as both the mount and the shifter itself can be rotated until a comfortable position is found.

Setting up the shifters once mounted can be a bit tricky but nothing too difficult. The right hand shifter sits on a collar that has a number of different positions, so if you’re not careful when the shifter is first screwed together (they are delivered in pieces, not as a single unit) the gear selection can be all over the place. This is easily resolved by slackening off the cable: Undoing the screw allows removal of the shifter so the collar can be rotated 90 degrees. This also allows the shifters to be set up for either 9 or 8 speed, which is useful if thumb shifters were wanted now but upgrading to 9 speed was a future project.


Cable tension can be adjusted on the rear mech as there are no adjusters on the shifters themselves, although they do come with down tube adjuster mounts, which could probably be modified with a bit of imagination. Tension on the front mech is much easier: As the front shifter is friction, rather than indexed, all that is required is for the cable to be pulled tight, moving the shifter does the rest of the work.

I have been very pleased with the operation of the thumbies since fitting. Gear changes are far quicker, and I’m sure more accurate, than with the previous XTR Rapidfires. And if you’re a weight watcher they weigh less as well.

The overall action is something akin to a single lever rapidfire with a satisfying clunk every time a rear gear is changed. The front friction shifter means that chain alignment problems between top & bottom gears front and rear are a thing of the past. If the chain is dragging slightly on the front mech cage just push the lever a bit and it will stop.

If gear shifting at the back goes completely out of kilter it’s an easy thing to rectify on the trial. Just turn the loop on the top of the right hand shifter and you’ve converted your 9 speed index into a friction shifter so you can still ride. Try that if you bent a mech hanger when using rapidfire or gripshift.

I seriously believe there is still a market for thumb shifters. They may not appeal to everyone, but their simplicity light weight & accuracy are hard to beat.

Simply put, I luv ‘em!