Shifting up issues

jamesfoz

Hi all.

I have this year replaced my whole drive chain with a Shimano 105, this included changing all cables of course. Has all been running very well, until yesterday when I experienced an issue with dropping down the cassette (so changing on to smaller sprockets). Changes the other way (up the block on to larger sprockets) are smooth but the other way is very clunky and takes a few seconds to change, length of time depending on which sprocket it is. The issue is worse in the large front chainring too, not sure if that is relevant.

I've looked on the forums and can see a mixture of responses but some say one thing or issues changing up and another for down. Most seem to suggest it's either just an indexing thing or that the cable may be snagging on the outer if dirt etc has got in there?

Any thoughts? Thanks.

jamesfoz

Just to add, the issue is virtually non existent when I have the bike on a stand testing it (there is very slight delay in changing on the smallest 2/3 sprockets but nothing out of the ordinary). So it would only seem to be an issue when the bike has power going though the drive chain. Weird.

AK_jnr

I would go with bent hanger. Amazing how far out they can be even when they look straight to the eye.

mfin

So, you are saying it is slow to change up. You've got up and down backwards, up means to a higher gear ie smaller sprocket on the cassette.

Friction in the cabling somewhere or simply the cable being a bit too tight. Try eliminating the latter with a clockwise click of the cable adjuster on the rear mech. If you can't find a balance where the upshift starts to behave fine without introducing a reluctance in the downshift then you most likely have a cable friction problem somewhere.

jamesfoz

mfin wrote:

So, you are saying it is slow to change up. You've got up and down backwards, up means to a higher gear ie smaller sprocket on the cassette.

Friction in the cabling somewhere or simply the cable being a bit too tight. Try eliminating the latter with a clockwise click of the cable adjuster on the rear mech. If you can't find a balance where the upshift starts to behave fine without introducing a reluctance in the downshift then you most likely have a cable friction problem somewhere.

Thanks. I said up and down the block, rather than up and down the gears as I know they are the opposite. I saw on other similar questions that responses were mixed because of this confusion so that's where I didn't mention 'gears' at all! My issue is changing up gears/down the block.

I have it working OK in the turbo but I have a feeling it might be different on the road. The bent hanger suggestion above is interesting as I did have a small off last week on that side. It doesn't look out of whack or bent but it might be very slightly, causing this issue lower down the cassette but not up the top.

AK_jnr

I was having problems myself last year and it wasnt until someone told me to check the hanger did I realise it was about 10mm out. It looked pretty straight too!

pilot_pete

AK_jnr wrote:

I was having problems myself last year and it wasnt until someone told me to check the hanger did I realise it was about 10mm out. It looked pretty straight too!

10mm out and looking straight! :shock:

PP

keef66

Is this the current 11 speed 105 (5800) or the previous 10 speed generation (5700, 5600)?

I have 5600 and the RH shifter eats the inner cable pretty regularly. Symptoms as you describe, ie reliable shifting to a bigger sprocket but hesitant / clunky going the other way. The cable's invariably fraying inside the shifter, and it's a good idea to replace it before loose strands start to migrate, and definitely before it snaps completely.