Shimano Front mech limit screws.
My wife has a mechanical ultegra 11 speed groupset on a liv langma roadbike around 12 months old. She's experiencing some chain rub on the front mech when in the granny ring and on the big cog on the cassette, which Im trying to eliminate. I've tried to move the the front mech a little bit further inboard but the low limit screw appears to be near it's maximum already...as per pic below.
So my question is, when setting up such a front mech from new, at what position should the limit screws be, all the way in, all the way out, half way?
In case I take the plunge in undoing the cable and starting from scratch.
Thanks.
So my question is, when setting up such a front mech from new, at what position should the limit screws be, all the way in, all the way out, half way?
In case I take the plunge in undoing the cable and starting from scratch.
Thanks.
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Comments
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Is it parallel with the chainrings ?0
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Wind the low limit screw out a bit to move the mech further inboard0
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The cable tension is probably limiting adjustment.
Have you tried using the trim function on the lever itself? An extra down shift ( left small lever) allows the mech to move further away from the chain.1 -
Shouldn't there be no cable tension when it's changed down into the small chainring?0
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If I was you I'd go back to the start and follow the guide here:
https://si.shimano.com/pdfs/dm/DM-RAFD001-02-ENG.pdf
Quite easy to do then you know it is set up correctly rather than relying on internet people to tell you to do this or that.Sometimes. Maybe. Possibly.
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As Photonic says.
I'd also use it as an opportunity to lob new inner and outer cables in so you know everything is groovy banarama..The camera down the willy isn't anything like as bad as it sounds.
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I was thinking this if its not parallel with the chainrings half turn either way might cure it .Though if tge limit screw is at its max it might suggest it needs reset anyway0 -
Ignore whatever I said earlier. I've read through the setup instructions linked by Photonic and it's clear that Shimano FDs are now set up in a completely different way to all my old-school agricultural kit.
If it was mine I'd be following those instructions to the letter and setting it up from scratch.0 -
Click your left hand STI inner lever 3 times so you're definitely in the lowest trim position. Look down at the derailleur from above, and slowly turn the L limit screw in. If nothing happens, i.e. the derailleur doesn't move outwards, then you're not even on the limit stop and excess cable tension is stopping the inboard movement of the derailleur. Adjusting the screw will not help you if this is the case.
The low limit screw plays no part in setup, so if starting again leave it wound out like it already is. The final step is to wind it in to close any gap and mechanically limit the inward swing of the derailleur (to reduce the risk of the chain coming off to the inside if you somehow lose cable tension).0
