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I'm planning to buy an 11 speed twist/grip shifter from SRAM (because they're the only one who offer 11 speed twist/grip shifter) for my vintage Japanese ladies bike but I'm quite confuse if it will be compatible with Shimano's 11 speed road rear derailleur. Why Shimano if there's a SRAM? I want my bike to have silver theme as possible, so I end up with shimano 105 silver RD. I didn't found any 11 speed with silver color in other brands.

Sorry for the noob question. I just started learning about bike components.

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  • Would you consider touching up a component with silver paint to make it blend in better ?
    – Criggie ♦
    Commented Jun 26, 2019 at 19:29
  • Depending on your definition of vintage (5 speed freehub?) 27 inch wheels? you may have a an issue with frame width(drop-out spacing) I would try to fit an 11 speed wheel first if it fits, then see if the brakes will reach.
    – mikes
    Commented Jun 26, 2019 at 20:47

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No, SRAM grip shifters will not work with a Shimano road derailleur.

The SRAM 11 speed grip shift units I found online use what SRAM calls x-Actuation which means a derailleur actuation ratio (length cable pulled to derailleur movement) of 1:1.12. Shimano 11 speed road uses 1:1.4.

Source for this info: https://www.artscyclery.com/science-behind-the-magic/science-behind-the-magic-drivetrain-compatibility/.

However, I think you probably have deeper compatibility issues that I should point out. If your bike is vintage then is will have narrower hub width than modern bikes, 120 or 126mm perhaps vs 130 or 135mm. An 11 speed cassette will not fit on a narrow hub which makes me think you actually have a lower speed bike. As the number of sprockets increases the spacing decreases, therefore you cannot use a 11 speed derailleur/shifter combination on a sprocket cluster with less than 11 sprockets, as the sprocket spacing will be wrong.

The basic rule of derailleur and shifter compatibility is the shifter speeds need to match the number of sprockets, and the derailleur needs to match the actuation ratio the shifter expects.

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  • I have modified my bike to to be compatible with 11 speed and also now have disc brake mount. You don't have to worry about that. I just need to know if it's compatible with Shimano RD or not. Then from your answer, I think I really need to use a trigger shifter by Shimano. Maybe I should go on painting my shifter to chrome now.
    – WashichawbachaW
    Commented Jun 28, 2019 at 10:51
  • @WashichawbachaW I think you’ll run into more problems. AFAIK Shimano does not have any trigger shifters compatible with road 11 speed groups (but does for 10 speed Tiagra). I don’t think MTB shifters will work either as there is a difference between road and MTB actuations ratios
    – Argenti Apparatus
    Commented Jun 30, 2019 at 14:06
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SRAM shifters use a 1:1 actuation ratio, whereas Shimano uses a 2:1 I believe. So, in short, no they will not be compatible. The Shimano derailleur is set up for a 2:1 ratio and would therefore not get the correct amount of shift from a SRAM shifter.

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  • aw Sad. :( Is it really impossible? Is there any other brand that offers 11 speed twist/grip shifter? You see I like trigger shifters but the problem is my handle bar is a porteur style handlebar. I can't slap a brake lever and a trigger shifter at one end because of the curve of the handlebar. Those two won't fit.
    – WashichawbachaW
    Commented Jun 26, 2019 at 15:09
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    Probably the best thing to do is buy a new derailleur that is compatible with the shifter that you want. An added expense but if it provides the desired result...
    – T_Bacon
    Commented Jun 26, 2019 at 15:14
  • @WashichawbachaW I wouldn't expect many 11-speed twist-shifts on the market. 11-speed is usually high-end and twist-shifts are usually on lower-end bikes.
    – David Richerby
    Commented Jun 26, 2019 at 16:12
  • Yeah I know but if you read my previous comment, I have a porteur type handlebar where I can't slap a trigger shifter and brake lever all at once because it won't fit.I have remove my front brake lever in my current setup to give space for my trigger shifter
    – WashichawbachaW
    Commented Jun 26, 2019 at 16:18
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    Shimano's 'classic' actuation ratio, used for MTB up to 9 and road to 10 speeds was actually 1:1.7. MTB 10 and 11 and road 11 deviate from that.
    – Argenti Apparatus
    Commented Jun 26, 2019 at 16:54

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