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  1. #1
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    2 speed front derailleur with converted 3 sp crank?

    I have a 3x9 SLX crank I just put on my Santa Cruz. Converted it to 2x9 using an outer bash. I'm needing a top swing front derailleur.

    Can I buy a 2x9 specific derailleur, or do the 2x9 cranks have a different chainline? Also, will my 3 speed shifter work with the 2x derailleur?

    Thanks for the input.

  2. #2
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    Can I buy a 2x9 specific derailleur, or do the 2x9 cranks have a different chainline? Also, will my 3 speed shifter work with the 2x derailleur?
    Yes, no, and yes.

  3. #3
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    I asked about this and the answers were very helpful.

    Removing Smallest Chainring?

  4. #4
    Trail Tire TV on blogger
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    can be done, takes more fiddling that just getting a 3x derail and turning the stop screw in to stop it at the middle ring.

    there actually is a slight diff in chain line between a 2x and 3x crank set... 2x the center line is between the 2 rings where a 3 by the center line is on the middle ring. But again, a bit of screwing around with settings/stops it can be done.
    Going to try and bring Trail Tire TV back. go take a look... http://trailtiretv.blogspot.com/

  5. #5
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    I did pretty much the same 3x => 2x conversion. Everything you have should work.

    Just adjust the barrel connector where it need to be with the shifter in the middle position, then tighten the H limit screw until it touches, then back it off slightly -- I don't want the screw adding additional tension to the cable when I am in the "middle" position.

    With the 3x derailler the chain would walk off the outside of the now-big ring when the chain was on the outer rear cogs. I tried moving the derailler down as far as it would go, but that caused it not to shift between the small and now-big ring properly. But with your bash ring I think you will be fine. Just leave the derailler clamped where it was with the 3x setup.

    I finally broke down and bought a 2-speed derailleur, which solved all my problems. My now-big ring is only 32 Teeth (I think 38T us the recommended minimum), so the FD won't go low enough to set the recommended distance between the teeth and cage, but it works great.

  6. #6
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    Quote Originally Posted by DennisF View Post
    I did pretty much the same 3x => 2x conversion. Everything you have should work.

    Just adjust the barrel connector where it need to be with the shifter in the middle position, then tighten the H limit screw until it touches, then back it off slightly -- I don't want the screw adding additional tension to the cable when I am in the "middle" position.

    With the 3x derailler the chain would walk off the outside of the now-big ring when the chain was on the outer rear cogs. I tried moving the derailler down as far as it would go, but that caused it not to shift between the small and now-big ring properly. But with your bash ring I think you will be fine. Just leave the derailler clamped where it was with the 3x setup.

    I finally broke down and bought a 2-speed derailleur, which solved all my problems. My now-big ring is only 32 Teeth (I think 38T us the recommended minimum), so the FD won't go low enough to set the recommended distance between the teeth and cage, but it works great.

    Thanks, I had my Trek converted to 2x9 in the front with the H limit screw buried and it worked awesome. I just figured I would buy the 2 speed derailleur for this frame.

    So you also used the 3 speed shifter? Has to be the same throw...

  7. #7
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    Yeah, I am still using the 3-speed shifter in the 1 & 2 positions. Throw isn't critical so long as the throw is long enough. The positioning for the small ring is set by the limit screw. You just need enough pull so that it shifts onto the "big" ring.

    BTW, there was a lot of slack cable in the small ring position with the 3-speed. I think this is because I wasn't pulling the cage as far with 2x as I was 3x, trying to keep the chain from walking off the "big" ring. There is very little slack with the 2x derailleur. The throw from 1 - 2 must be the same for 2x & 3x.

    With the 2x I can use all 20 combinations without any chain rub on the derailleur cage. The small/small combination rubbed with the 3x derailleur -- not something you would use anyway.

  8. #8
    Bicyclochondriac.
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    Quote Originally Posted by Hoban View Post
    I have a 3x9 SLX crank I just put on my Santa Cruz. Converted it to 2x9 using an outer bash. I'm needing a top swing front derailleur.

    Can I buy a 2x9 specific derailleur, or do the 2x9 cranks have a different chainline? Also, will my 3 speed shifter work with the 2x derailleur?

    Thanks for the input.
    Not sure about the 2x FD, but you can definitely use a 3x FD with a converted triple.

    I've been running 2x9 using various converted 3x cranks (small / middle / bash) with various 3x front derailleurs and shifters for 10 years. Always works flawlessly.
    15mm is a second-best solution to a problem that was already solved.

  9. #9
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by Hoban View Post
    I have a 3x9 SLX crank I just put on my Santa Cruz. Converted it to 2x9 using an outer bash. I'm needing a top swing front derailleur.

    Can I buy a 2x9 specific derailleur, or do the 2x9 cranks have a different chainline? Also, will my 3 speed shifter work with the 2x derailleur?

    Thanks for the input.
    No need for a different FD.
    With a converted triple it is as simple as adjusting the high limit screw on the FD. I would not even lower the derailleur to start. Shifting performance between the two inner rings should be no different than when the big ring was in place.
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  10. #10
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    The derailleur I'm looking for is SRAM X0, 2 spd, bottom pull, type S3 direct mount, 44T max.
    Having trouble finding this derailleur. (Looking for used.) Is there a Shimano version?

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