Gear cable snapping in sti shifter??

[Banjo]

I have had two snap in less than a year, both times towards the end of 200 km rides. The cable has snapped by the nipple in the Shimano 105 shifter.

Bodged a get U home repair by locking the cable under a bottle screw bolt to hold it in a middle gear .

Any ideas if I am just unlucky or should I change the cables more often. I do about 3000 miles /year on the road bike .

 

[oldfatfool]

I think I would be checking for a rough edge in the shifter that is sawing at the cable.

 

[I like Skol]

Great bodge. I must remember this one because i dont carry a stop screw sized screwdriver around with me.

 

[ColinJ]

Just be careful with gear cable bodges ...

I've just posted in another thread about my most serious bike accident which occurred when I was a teenager. My mate's gear cable had broken and his bodge was to wrap it round a seat stay and hold it in place with a clothes peg. We then decided to take it in turns to use the bike on a sprint time trial up a quiet local street. I was out of the saddle and going for it when the bike hit a bump, the clothes peg came off, the gear cable came loose, the bike slipped out of gear and I dived over the handlebars at 25 mph, landed on my head and used a shoulder and a knee as brakes. It wasn't exactly a pleasant experience ...

 

[I like Skol]

Just be careful with gear cable bodges ....................... It wasn't exactly a pleasant experience ...

Stop being so soft! I did silly things like this dozens of times as a youngster and it never did me any harm.......?

 

[HLaB]

IIRC the two times I've had a snapped gear cable its been on the bike with 105 shifters and like the OP says right behind the nipple, so not really a place you can inspect pre ride I've just cycled home in the high gear; I could have each time fiddled with the high limit screw as my multi tool has a screw driverbut for some reason decided not too.

 

[ColinJ]

Stop being so soft! I did silly things like this dozens of times as a youngster and it never did me any harm.......?

It was when I looked at my shoulder and saw a big flap of flesh hanging off that did it ... I looked closer and under the grit and blood I saw this big shiny white thing and thought "WTF is that!" and then I realised that it was bone ...

 

[potsy]

Stop being so soft! I did silly things like this dozens of times as a youngster and it never did me any harm.......?

Mmmm

 

[Banjo]

Without stripping the lever down its hard to see whats going on.It looks a bit complex to me for stripping just to have a look.i think I will just carry a spare for now.

Re holding it in gear by winding the outer limit screw in I think on mine you wouldnt get across more than one or two cogs like that and I needed at least no 5 at first then adjusted it right up up to the granny cog for the final hilly bit.

A bike with downtube shifters would do me fine I think, much simpler and less to go wrong.

 

[CopperCyclist]

Without stripping the lever down its hard to see whats going on.It looks a bit complex to me for stripping just to have a look.i think I will just carry a spare for now.

Re holding it in gear by winding the outer limit screw in I think on mine you wouldnt get across more than one or two cogs like that and I needed at least no 5 at first then adjusted it right up up to the granny cog for the final hilly bit.

A bike with downtube shifters would do me fine I think, much simpler and less to go wrong.

Or go Di2!

 

[ohnovino]

I've had 2 gear cables go within the shifter (flat-bar trigger thingymabobs, rather than dropped-bar STI doodahs). Thankfully, both times there were symptoms from them fraying and I was able to replace them before they totally snapped. Now I take the top off the shifters and have a nose around every time I do a reasonably thorough service.

 

[compo]

I carry a rear derailleur and a rear brake cable in my pack in case of emergency. I carry rear cables as they will do the front as well to get me home. Having said that, in 55 years of cycling on and off, on good bikes and cheap old crap, I have never yet had a cable snap. Strikes me that with a lot of modern stuff built in service life seems to be getting shorter and shorter going by the reports on here of bits failing.

 

[Banjo]

I carry a rear derailleur and a rear brake cable in my pack in case of emergency. I carry rear cables as they will do the front as well to get me home. Having said that, in 55 years of cycling on and off, on good bikes and cheap old crap, I have never yet had a cable snap. Strikes me that with a lot of modern stuff built in service life seems to be getting shorter and shorter going by the reports on here of bits failing.

definitely worth carrying spares.Im off to LBS tommorrow for them. Just cleaned the bike and got the broken end out oif the shifter. Last time it broke right by the nipple this time theres an inch of cable still on the nipple so I think its just fatigue rather than a sharp edge in there.

I took this pic to show how to get the nipple out of a 105 shifter as someone suggested taking sti to bits.

My fingers are pointing opposite way that they would be when riding ie this pic is from the outside looking in towards the stem.
pull the rubber hood back apply a bit of brake if you cant see the end of the round nipple in the square recess then click down through the gears until you can.I stick a pin in the nipple (ouch) to flick it out of the shifter.

 

[I like Skol]

Having said that, in 55 years of cycling on and off, on good bikes and cheap old crap, I have never yet had a cable snap.

Me too, although not over quite as long and illustrious cycling career. I can't remember ever snapping a gear cable, at least since my teens. This includes old school MTB thumb shifters and the various flatbar rapidfire/sti incarnations that Shimano has tinkered with over the years. I can't comment on my latest aquisition, a road bike which has Tiagra 9spd integrated shifters but has only covered 400-500 miles from new. There is definitely something odd going on with all these cables snapping.

 

[robjh]

Bump an old thread rather than start a new one....

I've just had rear-shifter cable snap in the STi levers (Shimano 105, model ST-5600), sounds like the same thing as @Banjo and @HLaB. It has frayed and snapped about 1-2cm behind the nipple and right within the shifter.

Does anyone know why this happens - faulty installation of cable, cheap and nasty cable etc?

nb. I've got a triple on the front, and by screwing the rear derailleur end-stop in as far as it would go I ended up with 3 quite usable gears and rode another 30 miles on a club ride with no real ill effects - maybe I don't need all those gears after all