Lower Front Derailleur?

Discussion in 'Mountain Bikes' started by sansabar, Jul 21, 2009.

  1. sansabar

    sansabar New Member

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    It was all I could do to get it to shift properly again but I got it going. It just seems to have no margin for error.

    It just occurred to me that I might gain some room for error by lowering the derailleur towards the smaller gears.

    Any thoughts?
     
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  2. alfeng

    alfeng Well-Known Member

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    Is it the original derailleur?

    Did this always happen?

    Is it across all three chainrings?

    Is it an 8-speed? 9-speed? 7-speed?

    Is the largest chainring a 42t? A 44t? A 46t?

    How old are the shifters? SRAM? Shimano?

    Did the shifting problem begin to happen AFTER you changed the chain?

    Etc!?!
     
  3. sansabar

    sansabar New Member

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    Sorry for the confusion. I just noticed that the beginning of my thread was deleted for some reason. Here it is again.

    I swapped a standard MTB 44/32/22 crankset into my Gary Fisher 229 which came with a 48/38/28 crank.

    I shortened the chain to take up the slack created with a smaller crank.

    I managed to get it shifting properly after adjusting the front cable and derailleur but I have no room for play - I hit every gear but I have some drag and a bit of delay shift in others.

    The Shimano XL bottom bracket seems a little narrower than the stock Bontrager

    Since the largest chainring is smaller, I was wondering if lowering the front derailleur might help give me a little more room for shifting adjustment.

    Yes

    No

    Yes

    9

    44

    Orig/4 yrs

    Yes
     
  4. alfeng

    alfeng Well-Known Member

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    The height of your front derailleur should correspond to the largest chainring ... the recommended gap between the lower edge of the front derailleur's outer plate and the teeth on the largest chainring is about (?) 4mm.

    Others have disagreed on the following -- it has been MY observation that the chain(-type ... i.e., "width") should correspond to the front derailleur(-type) ...

    A long time ago, I found that using a 9-speed chain on an 8-speed drivetrain will result in bad indexed shifting on a triple crankset.
     
  5. sansabar

    sansabar New Member

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    Thanks for the reply.

    I have changed out many cranksets but they were usually on road bikes and never involved a larger or smaller outer ring. Lowering the front derailleur to offset the size difference made sense but felt more comfortable receiving some input before I made the move to more tweaking.

    The factory setup on the bike is front Deore, rear Deore XT and Deore LX shifters so the move to the LX crankset from the factory Bontrager Select shouldn't present any configuration difficulties. My thinking anyway.

    I'll try this setup for a while. Since I started doing all offroad stuff on the 229 that factory setup left me pretty limited - I stayed on the 22 ring most of the time. With the new setup it allowed much more shifting opportunities.

    Just want to feel confident in all of those shifts!

    Thanks again.
     
  6. swampy1970

    swampy1970 Well-Known Member

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