Gearing issue. Front mech chain rub.

1964johnr
1964johnr Posts: 179
edited March 2014 in Road general
I have a ribble Gran fondo with 105 group set with 10 gears available on each ring and have adjusted the front mech to my liking so that I can use gears 1-6 on the big ring and gears 1-6 on the small ring without any front mech chain rub. I could set it up to use a different range of gears, but no more than 6 in each ring. Any more than 6 and front mech chain rub and the accompanying annoying noise kicks in. It's not a big issue because I can use all of the gears I need and I know that some people just accept that you can't use the full range of gears due to crossover etc and see this as perfectly normal, but It seems a little strange to me. Is it the same situation for the professionals, or are they able to use the full range of gears on their bikes without any chain rub?

Comments

  • Baxter-Smythe
    Baxter-Smythe Posts: 65
    Not teaching Granny to suck eggs, but I'm assuming you are aware of the micro shift, that's the fine shift you get between the main ring shift, I use 105 as well and until I took this small shift into account I was setting it up incorrectly.
  • 1964johnr
    1964johnr Posts: 179
    Good point. I haven't got to grips with that yet. Maybe that will allow the use of more gears.
  • wongataa
    wongataa Posts: 1,001
    You should be able to use all 10 on the rear with the big chainring by using the trimming function on the front mech. You should be able to use 9/10 on the rear with the small chainring by using the trimming function on the front mech.
    I can do this with my Tiagra gears. 105 should be functionally identical. Look at the Shimano technical documents to see how to set everything up including the trimming.
  • dj58
    dj58 Posts: 2,223
    Have a look at this data sheet, explains the trimming function.
    http://techdocs.shimano.com/media/techd ... 702880.pdf
  • darkhairedlord
    darkhairedlord Posts: 7,180
    on a similar note I fitted a new 105 front mech at the weekend but ran out of time to test ride. I shipped the chain of the big ring on the way to work this morning so adjusted the cable on the barrel adjuster. After some time wondering why the mech wasn't changing its position I remembered I had recently gone all trendy crossed my cables in the "continental style". I had taken the rear well out of whack and am looking froward to a jumpy ride home tonight! Stylish!

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