Tiagra ST-4703 Shifter Not Working

[Cyclothesist]

Apart from eating gear cables I've found STI fairly reliable provided you give the innards a periodic squirt of GT85. A set of ST4500s are still going after over 15yrs of being on my daily commuter in all weather and seasons in Scotland. 5700 and 4700 shifters have also been fine. The only trouble I've had is fishing broken gear cable strands out when I've been tardy in replacing them.
Maybe I've been lucky?

[Brucey]

.... The only trouble I've had is fishing broken gear cable strands out when I've been tardy in replacing them.
Maybe I've been lucky?

things can wear out or break depending on the exact model but by far the most common faults are dried grease and broken cables. Very often shifters don't survive an episode of broken cables, because they get damaged when the broken bits are removed. Needless to say you don't have the same problem if the cable is largely outside the shifter. One of my chums had repeated problems with broken cables inside STIs on his commuting machine. Riding with him, I soon established the reason; he was wont to do many more gear changes than most people,and his gear cables wouldn't last 9 months without fatiguing and breaking. Using him as a guinea pig, I was able to establish that the life expectancy of cables inside STI shifters is typically about 150000 shifts. By routinely changing the cables at about 125000 shifts my chum's problem was almost completely cured.

[mig]

i was pondering just how many times i change ratio if riding a geared steed and came to the conclusion that it wasn't really that many. perhaps winters spent on fixed get me out of the habit. perhaps i'm somewhat oafish in riding style. perhaps i only ride on flatter roads. a geared commuter will soon be out of the shed, fettled and on the road. i'll be concious of how many times i change gear after reading the above.

[rareposter]

i'll be concious of how many times i change gear after reading the above.

If you use Di2, it keeps track of all that for you. Number of gear changes, time in each gear ratio and so on.
Although if you use Di2, there's also no issue with cables snapping!

[Brucey]

when I rode with my chum, it soon became clear that he changed gear at least ten times more often than I did. I guess that is what many years of riding a SA 5s hub does for you. To give you some idea, I worked out that you could nigh-on replicate the gear ratios using a derailleur system, but even I was surprised by the result.

If you started with a 7s 13-28T freewheel and simply omitted 3rd and 5th, you would be pretty close. Because the middle gear is
arguably doing the work of three, gear changes on a flattish road with a SA 5s hub can be few and far between.

[atoz]

I had an issue with a Tiagra STI triple shifter a while back, was failing to do clean shifts to middle cog in certain gears. Did the usual spray WD40 in the mechanism, as you do, with only partial success. Then it occurred to me to check where the bare cable went under the bottom bracket Sure enough, there was impacted gunge there. Cleaning this off and lubing cleared the problem.

That issue wasn't a total failure though, just a bit of maintenance overdue. You can get away with grubby double setups half of the time, esp if they're not indexed. Not so with indexed triples. And yes, I need ultra low gears where I live.