STI cable detatched?

nezumi · Postby **nezumi** » Tue Jan 28, 2014 6:45 pm

So, I started my ride home.

Got out of the carpark ok. Rolling along the road I shift down, all good. Pull up at the lights and shift up as I approach... nothing. Move off and try shifting some more, no joy. Feels like I have one click each way and that's it, and my rear mech just seems to be doing its own thing, eventually settling on the smallest cog.

I am guessing that my rear shift cable has become unseated somehow - does this sound right?

If so, is there an easy way to check/fix it, or am I up for a trip to the mechanic?

For reference, my levers/drivetrain is Shimano 105 - 5700.

RonK · Postby **RonK** » Tue Jan 28, 2014 6:53 pm

In all likelyhood you need a new inner cable.

ironhanglider · Postby **ironhanglider** » Tue Jan 28, 2014 7:15 pm

Is the inner cable still clamped firmly onto the rear derailler?

If so then the cable has broken or you have problems with the shifter.

If not then it may have just slipped.

Cheers,

Cameron

Duck! · Postby **Duck!** » Tue Jan 28, 2014 7:44 pm

Completely routine cable breakage.

Derny Driver · Postby **Derny Driver** » Tue Jan 28, 2014 7:48 pm

Cable snapped inside the lever. Have fun getting the frayed ball end out. That's about 5 hours work if you try it or 5-55 mins for a good mechanic.
Don't fiddle with the lever, take it to the LBS.

Tim · Postby **Tim** » Tue Jan 28, 2014 9:27 pm

Frayed, almost broken cable for me too earlier this week.
Less than six months and less than 5000km's.
Doesn't seem like great mileage for a super-dooper Dura Ace polymer coated inner.

R12RT · Postby **R12RT** » Tue Jan 28, 2014 11:12 pm

Same thing happened to me on the week end.

Took about 30 minutes to get the frayed ball end out of the shifter.

About 10 minutes to install the new cable and adjust the derailleur.

Derny Driver · Postby **Derny Driver** » Tue Jan 28, 2014 11:40 pm

Tim wrote:Frayed, almost broken cable for me too earlier this week.
Less than six months and less than 5000km's.
Doesn't seem like great mileage for a super-dooper Dura Ace polymer coated inner.

My son has Ultegra shifters, they routinely break cables at 3000km or 10 weeks. Sick of them failing at inconvenient times and the trouble to get the frayed end out, now I just change the inner every 8 weeks. I think perhaps the shifter mechanism is a bit roughed up inside, which makes them break prematurely.

Duck! · Postby **Duck!** » Tue Jan 28, 2014 11:53 pm

5700, 6700 & 7900 shifters have a "back door" on the inner face of the hood, which makes detached cable-head retrieval a lot easier.

All STI-type levers, whether they're Shimano, Campag or SRAM suffer the same kind of cable breakage, due to the quite tight wrap around the shifter guts. The problem is compounded by the use of stainless steel cables. The trade-off for the smoother material (therefore lower friction) compared to non-stainless cables is the fact that the stuff work hardens, becomes brittle and then breaks at the stress point where it wraps around the shifter guts.

lobstermash · Postby **lobstermash** » Wed Jan 29, 2014 12:45 pm

Hmm. Got around 3000km on my 105 cables atm... No issues yet, but is there a recommended change over km point (as a rough guide)?

Aushiker · Postby **Aushiker** » Wed Jan 29, 2014 2:10 pm

lobstermash wrote:No issues yet, but is there a recommended change over km point (as a rough guide)?

I change mine at 10,000 km. No idea if that is a recommendation or not but ... just trying to avoid a pre-mature failure.

Andrew

RonK · Postby **RonK** » Wed Jan 29, 2014 2:16 pm

lobstermash wrote:Hmm. Got around 3000km on my 105 cables atm... No issues yet, but is there a recommended change over km point (as a rough guide)?

About now would probably be a good time - for the rear shifter at least. They don't cost much and are easy to change (before they break).

nezumi · Postby **nezumi** » Wed Jan 29, 2014 2:22 pm

lobstermash wrote:Hmm. Got around 3000km on my 105 cables atm... No issues yet, but is there a recommended change over km point (as a rough guide)?

I've been reading up on this now to avoid a repeat.

Apparently you can shift all the way onto the big cassette cog, then shift all the way down *without* using the pedals. This gives you slack to the cables, which you can then push out of the levers to check for significant wear.

RonK · Postby **RonK** » Wed Jan 29, 2014 3:03 pm

As I've posted previously, it's easy to carry one of these in your toolkit to get you home in case of a breakage.

lobstermash · Postby **lobstermash** » Wed Jan 29, 2014 3:09 pm

Yeah, that's a clever idea and saves you mucking up the limit screw settings.

I'll be checking my cable tonight (assuming Murphy doesn't dictate a breakage on the way home!!!)...

nezumi · Postby **nezumi** » Wed Jan 29, 2014 4:16 pm

RonK wrote:As I've posted previously, it's easy to carry one of these in your toolkit to get you home in case of a breakage.

Technically, I *could* have kept riding, however I didn't like the prospect of climbing hills at 36 x 12. I need to learn more trail/touring skills for situations like this. If I had been on the trail someone would likely have stopped, but in the CBD I didn't neccesarily look like someone in trouble. :/

RonK · Postby **RonK** » Wed Jan 29, 2014 5:33 pm

nezumi wrote:
RonK wrote:As I've posted previously, it's easy to carry one of these in your toolkit to get you home in case of a breakage.
Technically, I *could* have kept riding, however I didn't like the prospect of climbing hills at 36 x 12. I need to learn more trail/touring skills for situations like this. If I had been on the trail someone would likely have stopped, but in the CBD I didn't neccesarily look like someone in trouble. :/

The point is, with this you could have selected an appropriate gear, say the 17t sprocket, and had two rideable gears to get home. Why would you want to rely on somebody stopping? And what makes you think they could have helped. Be prepared. Be self-sufficient.

nezumi · Postby **nezumi** » Wed Jan 29, 2014 7:48 pm

RonK wrote:
nezumi wrote:I need to learn more trail/touring skills for situations like this. If I had been on the trail someone would likely have stopped, but in the CBD I didn't neccesarily look like someone in trouble. :/
The point is, with this you could have selected an appropriate gear, say the 17t sprocket, and had two rideable gears to get home. Why would you want to rely on somebody stopping? And what makes you think they could have helped. Be prepared. Be self-sufficient.

I didn't say I *wanted* to rely on someone stopping - in fact I said the opposite, that I need to develop the skills so I don't have to rely on someone stopping. However, having never had this happen to me before, and having only had a bike with STI levers for 5 months, I had no idea that this was a possibility. It's not like there's a label saying "this is a semi-frequent problem, and here's the solution".

wombatK · Postby **wombatK** » Wed Jan 29, 2014 8:54 pm

Duck! wrote: All STI-type levers, whether they're Shimano, Campag or SRAM suffer the same kind of cable breakage, due to the quite tight wrap around the shifter guts

And therein lies another great advantage of the di2 shifters. Go the electronics

ironhanglider · Postby **ironhanglider** » Wed Jan 29, 2014 9:05 pm

wombatK wrote:
Duck! wrote: All STI-type levers, whether they're Shimano, Campag or SRAM suffer the same kind of cable breakage, due to the quite tight wrap around the shifter guts
And therein lies another great advantage of the di2 shifters. Go the electronics

Or DT shifters. Go the retrogrouches

Or SS/FG. Go the hipsters and trackies

Or hub gears. Go the hubbards

And despite all this I haven't had a gear cable break in decades.

Cheers,

Cameron