Adjusting a Sram X5 front derailleur?

chrisrahi9
chrisrahi9 Posts: 41
edited February 2017 in MTB workshop & tech
Hey!

I just bought a new enduro bicycle and when it came i found the front mech wasn't rightly addjusted. The bike has an X5 2 speed front derailleur. When the chain was on the second gear it rubbed against the outer cage of the derailleur and when on the first gear it rubbed against the inner cage of the derailleur. Now I know a little bit about how to adjust the derailleur as I have watched tutorials thus i know what the L H screwas and the barrell adjuster does. I have tried to adjust the derailleur and after many tries managed to solve the first problem which is the chain rubbing on the outer cage when in second gear. But the problem is that I didn't manage to stop the chain from rubbing on the inner cage when in forst gear. I have tried to turn the L screw and even though the cage was as far in as it goes the chain was still rubbing. Have also tried playing with the barrel adjuster but nothing happened. How can I fix this problem without taking it to the bicycke shop ?
Thanks!

Comments

  • JBA
    JBA Posts: 2,852
    Is it direct mount or clamped to the seat tube?

    If it's clamped it could be out of line and need straightening up.

    If direct mount it could be bent.
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  • JBA wrote:
    Is it direct mount or clamped to the seat tube?

    If it's clamped it could be out of line and need straightening up.

    If direct mount it could be bent.
    No it is direct mount but what do you mean by bent ?
    I mean it is new and I didn't notice something unusual.
  • Without seeing it, we can only guess.
  • The Rookie
    The Rookie Posts: 27,812
    Is the cage parallel to the chain or is it toed out or in? It's unlikely for the rear to be bent out but it could have been knocked in by an impact during shipping.

    Something happened when you turned the barrel adjuster, the cage moved further in or out unless it was on the stop!

    Go to parktool.com and follow the full process, does seem like a minor setup issue and some videos are rubbish.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Not overly sure you understand what the limit screws do still but hey ho. Also if you are using an inline barrel adjuster, with the high tension found in the front gearing it can sometimes just rotate as a single item and not actually expand/decrease.

    I would disconnect the cable and move the derailleur through its full movement by hand. Once you establish it does move through its full movement you can start. If you find it does not then you will need to unscrew the relevant limit screw.

    I put the barrel adjuster in the middle of its range and have the shifter in inner chainring position to start.

    With the derailleur on the largest chainring with chain stopping it from springing onto smallest reconnect the cable pulling it tight by hand. After tightening the cable when you carefully rotate the chainset the derailleur will change into the smallest chainring and tension the cable fully. If you still have rub on the cage adjust the barrel adjuster to place the chain in the centre of the cage.

    Now Adjusting the limit screws. The cable 'moves' the derailleur the limit screws do exactly that limit its range of movement. So you can screw in the lower screw to meet the heal of the derailleur. Once you think you are good go through the range of the rear gears to see how this effects chainline and see if you get any rub. If you do adjust using barrel adjuster but understand cross chaining should not be encouraged.

    Now carefully move up into large chainring, I say carefully since it may over shift and push the chain off the outer edge. If it shifts ok screw in the high limit screw to meet with the heal of the derailleur body. If it overshifts then screw in the limit screw to reduce the available movement at this point remember you are pushing against cable tension so you may have to release using the barrel adjuster slightly.

    Remember if you move the derailleur with the limit screws you may effect cable tension either be increasing or decreasing it dependent on which way you are going.

    Adjustment is a compromise between cable tension in the lower and upper chainring. Limit screws are simply that, stopping the excess movement of the derailleur to prevent overshift or dropping the chain on the inside.

    Good luck
  • Update: I found the chain ring is bent in one Place and that's the thing that was causing the rubbing. When I turned the pedal I noticed that the chain wobbles and comes Close to the derailleur Cage than continues normally. I have contacted the maker of the bicycle and they will send me a new crankset