When did you last change the gear cable?

I got caught in the very heavy rain last Tuesday, and the BSA got saturated (not to mention the rider).  However, it seemed to have dried out fairly well.

But this morning, going to and from the Community Bike Workshop at Plympton, I was having trouble getting the outside sprocket (high gear) on the cassette.  It would not change the final step unless I backed off, went down one, and then changed two at once.

Oiling and cleaning the chain made a slight improvement, but still not good.  The trouble was in the gear cable.  The plastic serving on the outer was cracked in a few places, and had probably let in a lot of water. So I decided that a new cable was in order. 

Off to Glenelg Cycles (on the BSA) to get a piece of outer 1700 long (bought 2000), and a new inner, just in case.  Back home and changed the cable, outer and inner both.  The resistance to movement in the old one is terrible, and the inner was quite wet when I pulled it out.  The difference in gear changing with the new cable is amazing.  (Friction shifter.)

Afterwards, I thought: How long has that cable been there?  Answer: 24 years.  I put it on (with the shifter on the left, not the present (normal) right) when I put a double sprocket system (18/14) on the SA 3-speed, long before the conversion to 18-speed in 1992.   With the 1992 conversion, the rear derailleur was left on (complete with spacing washers for 1/8" chain), and the shifter moved to the right side, and the front (triple) shifter put on the left. 

In retrospect, I probably should have changed it years ago, but... 24 years is a good life.

Views: 374

Comment by Don (Who's lost?) Nairn on May 6, 2012 at 4:57

Is it fair to suggest that whatever your theological beliefs there appears to be no eternal life for bikes ;-)

Comment by David Southern on May 6, 2012 at 14:18

@Don.  Amen.  There might be limited reincarnation, though.

Comment by Paul on May 7, 2012 at 1:43

24 years is a darned good innings for a shifting cable!!

I use an old grease gun to pack the cable covers before inserting new cables, I've only ever replaced them due to damage sustained during mishaps. 

Comment by David Southern on May 7, 2012 at 14:07

I use one of these, a motorcycle cable lubricator, on the cables of my BSA, which are all fully-encased types.  However, the outer on the gear cable was too badly cracked to allow the use of the lubricator.

The lubricator is used thus:
- disconnect the cable at the lever end.
-if needed, wrap the outer in some tape to make up any gap between the outer and the lubricator (motor bike cables are fatter.)
-place the lubricator over the cable, with the inner protruding through the slot in the end.
tighten the screw until the device tightens over the outer.
-using a pump-type oil-can, inject oil into the small hole until it comes out of the other end of the outer.
-remove device and reassemble cable.

If necessary, small cracks in the outer can be covered with heat-shrink tubing, or reinforced in advance where they are subject to particular stress, e.g. next to the headstem tube.

Comment by Paul on May 8, 2012 at 17:36

Yep, that sounds like it would work - also sounds easier than trying to pump grease through long cable outers!

Comment by Terry C on May 11, 2012 at 14:39

My LBS recommends changing cables at least every year. I usually go about two years, and I recently changed all cables, inners and outers, gears and brakes - -  big difference even though they were only two years old - - and make sure that the new ones are teflon coated.  

Comment by Terry C on May 11, 2012 at 15:54

I meant to add to previous post. Cable replacement is often indicated by a reluctance to change up, that is, to the next smallest sprocket. Changing down, to the next biggest sprocket is done by the cable pulling the derailleur across, whereas changing up to the next smallest relies on the spring tension of the derailleur. If cable resistence is high, the spring tension may not be sufficient to move to the next position. In David's case, it may also be partly caused by an aging return spring in the rear derailleur. Perhaps that is also due for replacement considering its age.

Comment by David Southern on May 11, 2012 at 23:59

@Terry.  The gear changing is now wonderful, without changing the derailleur or its spring.   The serving on the outer was badly cracked, and it was probably rusted on the inside.  A large kink in the outer where it passed the steerer tube didn't help either.  This is a continuous outer, 1700 long.

The new type of cable outer that is braided, with a plastic liner, looks as though it will be a great improvement over the older type,  which is a close kin to spring curtain-wire.

(Spring curtain-wire with a baling-wire inner make good remote-controls for model railway points.)

Comment by Terry C on May 12, 2012 at 9:44

David, glad to hear that all is well. What appears to be a plastic liner, may in fact be teflon. Most cables made today do have that feature.

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