105 front mech shif...
 

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[Closed] 105 front mech shifting issue

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My son’s cross bike has 5800 105, I am having trouble setting up the front mech. To get it to shift to the big ring I have to have so much tension on the cable that when it’s on the small ring/biggest sprocket the mech won’t return far enough and the chain rubs on the cage of the mech. If I release some of the cable tension so that it doesn’t rub, I can’t get it to even try and move the chain onto the big ring. Any ideas? Thanks.


 
Posted : 07/02/2022 9:00 pm
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Cable routed correctly around the pillar and under the bolt?


 
Posted : 07/02/2022 9:16 pm
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https://si.shimano.com/#/en/DM/CS0004


 
Posted : 07/02/2022 9:19 pm
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There are two cable routes on those, I think. A pin on the back alters it.


 
Posted : 07/02/2022 9:21 pm
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Look at YouTube how-to clips - recent model Shimano front mechs are a bit more tricky to set up and to make sure there’s no slack in the cable and to get the trim function to work.


 
Posted : 07/02/2022 9:22 pm
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5800 isn't new style


 
Posted : 07/02/2022 9:33 pm
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Use the tech doc linked and you can't go wrong


 
Posted : 07/02/2022 9:34 pm
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Use the tech doc linked and you can’t go wrong

That appears to be a tech doc for an 11 speed cassette? 😉

I had to check the model number, some places are selling the new style as FD-5800 confusingly.


 
Posted : 08/02/2022 9:28 am
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thats weird as copied it from the link i had open 🙂


 
Posted : 08/02/2022 11:42 am
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I had intermittent problems shifting from small to big ring recently. Thought it was the cable but when I put a new 52t ring on to deal with another issue (chain skipping on gears at back as 52t was heavily worn) it solved my front shifting too. So I'd check the teeth on the big ring if it's a bit old.


 
Posted : 08/02/2022 11:50 am
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I had missed the little peg. Re-routed the cable round the peg and now all good.

Thank you.


 
Posted : 08/02/2022 11:55 am
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This thread has reminded me to check the white cable guides just inside my 505 brifters, they're a ~£2 part that is infamous for wearing through.

Think I need to finally fit the compatible 6800 spare rings, my 5800 105 is looking a bit like shark teeth and doesn't shift to the big ring reliably.


 
Posted : 08/02/2022 12:00 pm

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