I keep a pretty close eye on chain-wear and cassette and ring wear on all of my bikes. I sometimes allow these components to wear a bit more than I should, but at least I'm aware of their condition.
I have too many bikes and too little time and cash to thoroughly go through each bike with any regular maintainance schedule. I've made a conscious decision to "Run to Failure". I've not yet had a severe "Break down" while out on a ride.
So far I've been able to pick up on needed service before it's become an "Issue". For example, last summer I could feel a slight roughness in the front hub on one of the LWB recumbents. I did a thorough cleaning and repacked the bearings setting things right enough for my usage.
My luck almost changed last week with my Tour easy while out on an 80 mile group ride. About 50 miles into the ride I could hear and feel some grinding from the rear cassette in what I thought were the two lowest cogs. I opted to ride-on and deal with the issue at home, and of course not use the lowest gears. The last 15 miles were on gentle rollers into a stiff head-wind and the going was pretty tough but I made it back to the start/finish point and loaded the bike into the Van and headed home.
The following day I went out to the garage and popped the bike up onto the repair stand to sort things out. To my suprise I discovered that the chain wasn't even shifting down to the three low cogs. No wonder the last 15 miles were so tough! Any way...I spent about ten minutes trying in vain to get the cable tension properly adjusted and was getting nowhere fast. It seemed O.K. until I ran up and down through the gears and then it was all mucked up again.
O.K...this is where I always sit down, look at what's in front of me, and ponder for a bit. Lucky for me, my curious bride chose this moment to wander into the garage to see how things were going. I put her straight to work operating my shifter and the crank while I positioned myself back at the deraileur to watch what was or wasn't occuring. (Remember now, this is a 67.5 inch wheelbase....long way from the shifter to the back of the bike) That was when it happened! The rear deraileur cable snapped up at the head, in the shifter.
That explained all my symptoms...as the cable started breaking and stretching I was slowly loosing control of the rear deraileur. No rocket science here.
Now for the cool part. In the peace and quiet of my garage I sat and looked at the bike up there in the repair stand. The slack cable hanging along side the frame, the deraileur out to the stop, the chain in the small cog, and me thinking "What would I do if this broke out on the road?".
It took a couple of minutes to resolve this imaginary breakdown, but I think I have a good plan if it does occur. On my recumbents I have attached flag holders with small hose clamps. Being a silly old coot I carry a couple of spare hose clamps in my tool bag. It would be a very simple roadside fix to just pull the cable taught enough to get the chain in the cog of my choosing and the clamp the cable to the frame. Tying the cable off would accomplish the same end but would be much more tedious. With the cable clamped in place and the triple crank up front I would essentially have a three speed and could continue riding.
Naturally, I have ordered two tandem length shift cables. One will go on the bike and the other will be in my tool bag. I'll pick up some brake cables while I'm at it.
I don't know if I would have been calm and composed enough to figure this out if it would have occured on the road but fortunately I didn't have to find out. Stubborn old Cranky will be toting spare cables from now on though.