I'm heading out on a long tour soon on a bike with Shimano STI shifters. That choice was intentional as I don't like bar-ends. However, I notice the gear cables run through stops at downtube shifters bosses and I'm curious if there's a type of cheap friction shifter that would mount on those and could be used on either side that I could carry as an emergency replacement in case an STI ever crapped out.

Here is a picture of the bosses on this bike: Downtube shifter boss

If someone could point to one or more specific models that would fit this, that would be great. Again, the emphasis is on cheap. If I break an STI, I would only need this to limp a day or two to the next major city (tour is in Canada). So I don't want to drop $100+ on some bespoke hand-milled stainless steel shifter.

  • 3
    Another option would be to just pick a mid gear and tie off the cable at the derailleur. How many spare parts are you going to carry? What are the chances of a shifter going out (even an STI)?
    – paparazzo
    Jun 5, 2015 at 16:17
  • You'd need to carry a spare shift cable, something to cut the cable with, and the shifter as well. Blam's idea is better, but if you want to do this, Sunrace probably makes the cheapest set (maybe 10-15 USD for both left and right).
    – Batman
    Jun 5, 2015 at 16:35
  • And I doubt it would be ambidextrous and no guarantee that is a proper mount.
    – paparazzo
    Jun 5, 2015 at 19:00
  • @Batman I don't think he'd need a spare shift cable or cutter, unless the anchor that's already on the end of his shift cable wouldn't work on the downtube shifter and he wouldn't necessarily need to cut the cable as long as the cable end isn't frayed enough to keep it from sliding through the housing (a small amount of solder may help here) -- if the STI shifter breaks, he'd just pull the inner cable all the way out of the housing and shifter, then thread it back through the downtube shifter. Though I agree with Blam - if the shifter breaks (unlikely?), just tie off the cable to a mid gear.
    – Johnny
    Jun 6, 2015 at 1:13
  • For what it's worth, I have (relatively) cheap Tiagra STI shifters on my commute bike, and after 5 years and about 10,000 miles of commuting through rain and shine, they are still going strong. I almost replaced them with 105's or Ultegras when I bought the bike, because I thought they wouldn't last long, but they've never been a problem. They don't shift as crisply as the Ultegra drivetrain on my road bike, but they've never failed. On the other hand, the Sora's on my wife's bike caused no end of problems, so we replaced them.
    – Johnny
    Jun 6, 2015 at 1:19

1 Answer 1


We need to see what is under the cable stops. My guess is that is is probably a standard squared off shifter boss, but you never know. If it looks like this

Shifter boss mount

Then any friction downtube shifter should work as a backup. You want to get one that is not indexed if at all possible since that way you can use it for either front or back derailleurs. Bar end shifters use the same mount, so if you have some of those handy you can see if they fit. The cheapest solution is probably to buy a cheap pair of Sunrace Clamp-on stem friction shifters.

While the levers are different, they can be interchanged. You should probably test this in case there are clearance problems and you need to trim the lever a bit.

As to whether this is worth the cost and weight, I'd say it depends on the remoteness of the tour. If you're within a day's ride of a bike shop for the entire tour, then it's probably not worth it. A credit card makes a handy backup for a lot of parts.

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