Stiff little linkers

So having installed the new chainring I thought the day is sunny and I have half an hour free time. Why don't I take the bike for a little rattle down the local treelined hill, and see what shakes out. No sooner do I leave the house and get up the road than there is a horrible clunking noise from the back. A regular little skip like a heart beat gone wrong, and a rattle and a clunk that sounds like the chain wants to move to the next gear socket. Then the chain falls off at the front.

Okay.... so perhaps I have miscounted the links on my chain and so its the wrong length. Only I could have sworn I had measured correctly. Perhaps then I have not adjusted the rear derailleur for the new front chainring? This seems like the easiest problem to start on, and so armed with my trusty screwdriver I set about the limit screws in attempt to solve the problem by the roadside.  10 minutes later and I limp the bike home clunking like the mechanical equivalent of an asthmatic who has forgotten his inhaler.

Its a week before I get a chance to sit down and review the problem. There is no way it is a the derailleur. Everything is perfectly set up from the start and the adjustments did not affect the problem one bit. Nor is it the chain length as I check again.

Perhaps it is time to revist the potential chain cross problem that I feared was a factor in losing the chain when riding with the larger 42t chainring. I get the calipers out (yes I have some, very cheap from B&Q) and start measuring. The final measurements in and I discover that actually with everything on I'm probably a few mm short of the perfect chain line. I can afford to put the chain retention device on.

So some happy time putting the taking off the bottom bracket and we are in business. Only we are not - there is still the irritating hiccup, even though the chainline looks near enough perfect by eye. So I do what I probably should have done when I put the front chainring on, I look at the chain itself. What do you know one little stiff link. Rigid and immobile and so unable to bend round the jockey wheel.

Fixing this is a cinch, if you have a chain tool, which you should by now. First I tried just wiggling it and applying some lube in case it was caused by grit or dust. Of course for me it isn't but you never know it could have been that simple. Instead I reverse the chaintool and give the central pin a little squeeze back. It works! I am up and running yet again.