Internal gear cable breakage.

[Cake]

I was happily cycling along on my RT yesterday when it suddenly became difficult to shift from 12th to 11th.  It went in eventually but was still stiff.  It then got stuck in 8th and finally i was left with no other gears than 5th and 6th (which shifted perfectly!). 

I was a bit puzzled and suspected the internal gear cable but the symptoms i had read about the cable snapping (being left in 1st or 14th due to twisting the shifter while finding out hats going on) were not what i experienced.

After removing the wheel and the plate it was obvious that the cable had frayed and anchored itself in the concertina covers and around the mechanism.  A bit of a fiddly job to sort out but its up and running and i won't be worried about doing it next time.

I was a bit surprised it had gone at 9700 miles, but there you go.  I can't really see the cable suddenly snapping completely - fraying seems more likely, but i may be wrong.  I think the main reason it went was that i had tempted fate by saying (only 2 days before) that the bike had done almost 10000 miles and i hadn't even had the back wheel off before! 

[geocycle]

That's tough luck.  9700 miles seems a bit short relative to what Andy Blanche suggests.  I was expecting to change cables at around 12000 miles (next year for me) but might have a look earlier now.  Glad it was sorted quickly and you stopped in a ridable gear.

[pdamm]

Mine failed in a similar way after about 18,000 km (~11,000 miles).  I ended up in bottom gear, probable because I was going up a steep hill at the time.  Since then I decided to change it every 15,000 km.  But from your experience Cake, that is about where yours failed.  Maybe I am being too optimistic?  Time will tell.

Peter

[stutho]

I keep on expecting to change mine.   I have got the spare cable sitting in my tool box. (This summer I took it with me when I went on tour.) But as yet everything is still running sweet I am closings in on 17,000 miles.  Funnily enough I have change the shifter cables  and the brake cables.

I have an oil change due the end of this month - I may switch out the cable then but I am such a skin flint that I will probably wait to it final goes.  I do inspect the cable from time to time - and give it a little lithium if I think it needs it.  Last time I look it was still fine, but I get the feeling that as soon as it starts to go it jams up pretty quickly -  So my inspections are  probably redundant.

So after saying all of this you can guarantee mine will fail tomorrow morning on the way into work!!!

     

[davefife]

Suspect I have the breakage.  This morning on the commute exact same experience as Cake, I reckon I am stuck in 10 or 11 - so its honking up the hills on the way home can't access my total mileage etc from this pc, but will check it out later on (hopefully repair) and report back.

[geocycle]

Hard luck Dave.  Hope you get it fixed OK.  Look forward to your report. 

[Cake]

As Geocycle said, Dave.

[davefife]

this is what my cable looked like once removed. its frayed inside both concertina tubes and at the wrap round the central boss, the cable is unwound in the photo and this fray is the one on the top right.  I also found that the wearing surface on the inside of the big round boss that bolts to the hub (the black circular piece) was pretty rough, obviously with the frayed cable acting upon it.

The RST is nearly 4 years old and has covered 18,000km, so "20,000km service intervals" as quoted for this item is about right.
Changing the cable was very straightforward, I followed the owners manual instructions and had no troubles.  The ride home on Tuesday was ok in 10 or 11 - my grip shift is totally worn - maybe I shall wait for the fashionistas to be selling their fixies at knock down prices and give it a go

[Cake]

Yes, that looks very familiar!

[biking_fox]

Useful thread - was very puzzled today to find I only had gears 11-14. got home OK though.

Looks like the same problem - very badly frayed on one side only. I've ordered the easy cable kit for the replacement, next time I might try just the cables.


Bit peeved that I've only done 3000miles on it though! Could this be a riding style issue? I haven't been that careful with gear shifts. Or just bad luck?!

[davefife]

3k seems not a lot, on your frayed cable loop i would check the boss for burrs, and the routing of the cables.  You would really need to be "abusive" in your gear changes for it to be a riding style issue, so maybe bad luck, always worth telling thorn/blance about what you may consider premature failure, they always listen and readily consider such technical issues, often waiving replacement costs.  Genuine bikes and genuine people at Thorn.

[Cake]

I think mine has gone again, i can feel the fray in one of the concertina covers when sliding it back an forth. I didn't get much notice this time and was then stuck in 8th, which could have been worse! 

Seeing as my RT went past the 15000 mile mark while on the return journey home, that's only about 5300 miles since i last replaced it. 

I think its also time to replace the shifter cables.  And an oil change is due.

[davefife]

better recheck mine

[Cake]

All replaced and working.  No signs of wear in any of the components, so just the cable replacement.  I cut the cables to 165mm and it is right on the limit regarding the cable tension adjusters if not a little tight for my liking in 1st / 14th.  I'm sure some use will sort that.  Next time i'll cut them to 170-175mm.