105 front mech setup

MAMB

Having ridden MTBs for several years with Shimano trigger shifters, I've got used to the setup and 'feel' of this type of gear shift. For the past six months I've had a Giant SCR1 road bike and I've never felt as happy about the quality of the front shift compared with that on the MTB. The bike is fitted with 105 STI shift levers, a 105 front derailleur and FSA compact chainset. The 105 rear derailleur works perfectly but the front is another matter: to get an acceptable shift from the small ring to the big ring, the cable tension is such that the lever operation on trimming or downshifts feels very 'clunky'. If I slacken off the cable tension to reduce the 'clunk', the upshift is very hesitant. The upper and lower limit settings are as per the Shimano service instructions for this derailleur.

Before I spend any more time trying to achieve shifting perfection, have any other 105 users experienced similar problems with their front mech setup ?

maddog 2

if the shifters are triple-ready then you can either set them up to shift from click 1 to click 2, or from 2 to 3, given you only have two rings on your compact.

If this is the case, I usually go for the 2 to 3 setup, as the other setup can be clicky/snappy as you suggest. Clicking down to click 1 will obviously leave the cable fairly loose, but the limit screw on the mech will stop the mech going anywhere, which is the main thing.

If the shifters only have two clicks then ignore all of this.

MAMB

I think all the 105 shifters are triple-ready so I'll give it a go. What I don't understand though is why the 2-3 shift should make any difference over the 1-2. I assumed the shifter essentially pulled (or released) a given amount of cable inner for each shift. I was beginning to wonder whether I'd got an unusually strong return spring on the derailleur. It really does make one helluva clunk on the downshift.

bice

The tension on the front mech is considerable. On a bike I am assembling at the moment I am going to use the down tube friction shifter for shifts on the chainrings, and Ergopower 8 speed on the cassette (which is a Campag STI).

keef66

I think it's normal. I've just gone from elderly XT mechs on the mtb to a 105 triple on the roadie. First time I swapped chainrings I thought I'd broken something the noise was so agricultural. Got used to it now. Not quite as noisy if you really back off the pressure on the pedals while changing.

In contrast the rear mech just purrs like a sewing machine.

cooper.michael1

I had the same problem, it is well known with 105, and eventually the left hand shifters break becuase the tension is so high to get it to shift. There are dozens of single right hand levers for sale over the months on Ebay.

Im in the process of swapping to campag, after years of happy Shimano MTB use.

fnegroni

cooper.michael1 wrote:

I had the same problem, it is well known with 105, and eventually the left hand shifters break becuase the tension is so high to get it to shift.

I too had a similar issue until I just spent some "quality" time with the front derailer so that the second click engages the big ring with yet some more room to spare for an extra trim click if necessary.

I also strongly recommend using a braze-on type front derailer as it helps ensuring the gap between itself and the big ring is just enough to clear it (1-2mm)

cooper.michael1

Got my replacement 105 lever today. Has a warning on from Shimano saying 'the shifter will break very easily' if the cable is stretched too much. Although the new one does look sturdier than the off the shelf version with more metal internals.

Design fault, for something costing £200, not good enough....half the price and the Veloce levers are not as pretty, but better!

Nuggs

IME 105 shifters are particularly rubbish when paired with FSA chainsets.

I swapped mine for an FSA front mech and it was beers and cheers all round...

markos1963

My 105 front is very noisy compared to the rear. When riding in a group almost everyone looks around when I change rings as they think something terrible has happened!

John.T

The cable tension needs to be set so that the mech is not hard against the limit screw when on the big ring. Pushing the lever across should just move the cage a little further. Not having this clearence is the main reason for so many breakages.

skyd0g

I have got the same problem/design fault on my Tiagra shifter - very agricultural, especially when compared to the old XT thummies on my MTB.

It appears to be made worse by the fact that there is a large amount of lever movement & pressure required to get up to the click index point, therefore when you release the mech to go down from the larger front chainring to the samller there is a big "clunk" as this tension is released. I hope Shimano will get a "softer" spring for the next generation of shifters.

...otherwise make mine an Italian. 8)

bice

I would not care too much about the noise. My Campagnolo Centaur levers and front mech make a racket, and at one point the cable used to spring back one rachet as it was so tight. I have adjusted that. I find my 105 triple less noisy and smoother, actually. But I am aware of its reputation. If it breaks, I will just use a downtube shifter for the chainrings.

John.T

The spring has to be strong enough to shift the chain even with a bit of load on. I have used DA and Ultegra for years and have never had problems.

bice

John.T wrote:

The cable tension needs to be set so that the mech is not hard against the limit screw when on the big ring. Pushing the lever across should just move the cage a little further. Not having this clearence is the main reason for so many breakages.

I reckon this post is really useful and had not occured to me. But having a bit of clearance after getting onto the big chainwheel before hitting the limit screw makes sense. It is what I got wrong with the Campag set-up I described. I must remember it when doign my Ciocc with Shimano 600 stuff on it. Thanks.

bikeman456

I know this is an old post but it comes up top in search and so might help others.

I had this problem with SRAM Rival, stiff front derailleur and a loud clunk when shifting to the small ring. I found that it was caused by a misrouting of the cable through the anchor bolt such that excessive force was required to overcome the poor leverage.

To work correctly the cable needs be routed outside of the cable pinch bolt tab. In this position there is greater leverage and hence less force is required. see image at http://brimages.bikeboardmedia.netdna-cdn.com/wp-content/uploads/2013/01/New-SRAM-Red-review-install-notes-front-derailleur-cable02.jpg The right hand image is correct despite appearances.