My front shifter on my road bike failed the other day, on a ride home. They were two year old 105, so that's not a great record but fair enough, sometimes sh*t happens. Dismantled it when I got home, found that the little pawl thing activated by the small upshift lever had broken off its spindle.

Got a nice deal from the nice LBS man on new Ultegra which I fitted. Now – I'm running a triple shifter because I like to run triple usually but currently I'm running double (long story). That's no problem – the double chainset is the one that came on the bike with the original triple so I know it works. I also know that it can get a little stuck if you overshift into the big ring whilst runng double but there's only just enough adjustment room at the mech, and it kind of gets a little jammed in there – I'm aware of this.

So when I was fitting the shifter, it got stuck kind of randomly – wouldn't move either way. So I jiggled and wiggled and got it working but it didn't work properly – it'd shift up to the third position but if you went to downshift it went all the way to the first. Well I thought I'd contact them about this but since I need the bike and it was working in double mode I did a few commutes on it. Well half way home it packed up completely – great.

Nice LBS guy said ';oh that is weird, bring it back – they've had a few faulty ones' and he changed it for me but didn't set it up. I went to do this at home and immediately I wired it up it got stuck and ended up the same way as the first replacement. So I persevered and found that this one wouldn't work at all if there was any tension in the cable. So I called up the nice LBS guy and he said 'no, really? Bring it in tomorrow (that was yesterday), I might have something I can lend you whilst we send them off'.

Well I went in today and nice LBS guy isn't working, it's less nice LBS guy who basically said that I'd broken them. I asked how one breaks STI shifters to which he replied that you just force them. Well, if a shifter is working you don't need to bloody well force it anywhere do you? Plus, I've been maintaining my own bikes for 20 years including replacing and re-fitting several sets of STI shifters and loads of front mechs on road bikes and many more on MTBs. I know damn well how not to force things.

So – has anyone else had some from a bad batch of these shifters? Each time it seems to be the same thing – the upshift pawl (on the top of the mechanism) snaps off its spindle. The plastic cover and cage seems to hold it roughly in place which is why they kind of work for a while even after they break. I think the second set were actually broken to begin with because they never worked at all as far as I can see.

I've broken a left hand shifter after forcing it to change in the mud an cack, if they don't shift with a gentle push as normal, forcing it just snaps the guts inside

Shimano have had an issue with 105 L/H shifters for the last 18months/2yrs, mainly OEM stuff. It is possible you have had a duff original lever that just hung on a bit long, I haven't heard of any Ultegra levers suffering the same fate but Madison are reasonable with returns so get them sent off. When Ultegra shifters are fitted and working correctly they are very smooth and require very little effort to shift, either yours are duffers or fitted/set up incorrectly

I had a cable fray which caused a stickyness in the lever movement. It progressed to the point where the lever wouldnt move at all.

same things happened to my ultegra, swapped under warranty

This is stuff that's been fitted with brand new cables and is all clean and new. I'm clearly not forcing a cacked up system to move where it doesn't want to – obviously I wouldn't be wondering why it'd broken…

In any case – they fitted another one (they wanted to do it themselves) fair enough – but interestingly, they feel totally different. The two broken ones were always wooly and stiff right from the off, but these new ones are really light, snickety snick and positive. So clearly there was something up with both pairs of previous.

were the cables prefitted molgrips ?

seen some shonky customer fit jobs where they havnt sat the cable right ….shifted up and the cable head not being sat right has jammed up the internals of the shifter – once the customers then rammed it and it freed off but not before snapping off the lug you mention …..

I was careful to get the cable seated right. One of the first things I thought of when it went shonky. And I never ram things to make them work! 🙂

Mine was fitted by the bikeshop and had worked fine for three months before it went bad