Please help with my gears

Hi guys, I’m having an issue with my gears, when I have the front mech on the largest cog (outer) and the rear on the largest cog (inside) and I pedal backwards gently the chain drops from the largest rear gear down 2 gears. I cannot figure it out it’s frying my brain, does anyone have any experience in this area that may be able to offer some advice, I have searched the net but I don’t seem to be able to find the issue.

Thanks
Guys

Comments

  • Mad_Malx
    Mad_Malx Posts: 5,172
    This is the known as cross-chaining. Sometimes you might do this accidentally but should try to avoid it. (I know 1x do pretty much the same).
    The chain line is poor so when you pedal backwards, releasing the tension, the chain drops down the cassette. Cross chaining puts a lot of side strain on the chain and cassette so will result in more rapid wear. Big-big probably pulls the derailleur too far forward too, and if the chain is a bit short can be catastrophic.
  • Mad_Malx said:

    This is the known as cross-chaining. Sometimes you might do this accidentally but should try to avoid it. (I know 1x do pretty much the same).
    The chain line is poor so when you pedal backwards, releasing the tension, the chain drops down the cassette. Cross chaining puts a lot of side strain on the chain and cassette so will result in more rapid wear. Big-big probably pulls the derailleur too far forward too, and if the chain is a bit short can be catastrophic.

    I did think it could be the chain being too short, thank you for the advice I will take a look and research cross chaining. I am quite new to it. Thanks guys
  • flasher
    flasher Posts: 1,734
    Don't pedal backwards!
  • vincesummerskRoxcBTr
    edited March 2021
    Not sure cross chaining is like to cause much of a problem with double chaining systems, unlike with front triples.
    Is there actually any proof that it causes a problem with doubles?
  • webboo
    webboo Posts: 6,087

    Not sure cross chaining is like to cause much of a problem with double chaining systems, unlike with front triples.
    Is there actually any proof that it causes a problem with doubles?

    Yes the chain drops down two sprockets when backpedaling. ;)