Chain Wear: For The Want Of A Nail
I really like to ride my bike. I’ve always liked to ride. But it’s only over the last couple of years that I’ve been using it as my main mode of transport locally. The numbers speak for themselves:
- From when I was eleven, I did something like 500 miles between 1981 and 1985 on my Junior Dawes Lightning.
- Last year I did just over 3,000 miles, and this year it’s somewhere just over 2,000 miles. And a whole lot of grinning like I was eleven years old again.
Anyway, when I was a kid, bike maintenence involved putting some 3-in-1 oil on the chain every now and then, and cleaning the rust spots off the chromed steel wheels. I think that by the time I grew out of my Lightning, it was still on its original set of brake blocks!
Not so now. But I’m still learning / making it up as I go along.
Resources like the various maintenece vids on quickrelease.tv help - like this one that’s the Standard Operating Procedure for cleaning your bike:
. . . and there are a whole bunch of others, guides online (an especially big thank you to the Late Sheldon Brown).
Anyway, I’ve made a big mistake . . . I didn’t keep on top of chain wear on my Sturdy Commuting Bike, Wilf. Chain wear happens over time, as road grime worms its way between the rollers and the pins. This is a hugely effective grinding compound, which over time wears the inside of the rollers away. The result of this is that the chain stretches.
“So what?”, you ask.
Well, as the chain no longer fits perfectly between the teeth of the chainrings, sprockets and chainwheels, it now starts to wear them away to fit the now longer-pitched chain. Symptoms include a noisy drivetrain, notchy & inprecise gear changes, and a little harder work (by a percentage or so) as the efficiency drops. Let it get worse, and stopping to re-fit the chain to the becomes a regular feature . . . and eventually the chain fails. Probably when you’re stomping on the pedals, up a steep hill and in heavy traffic. You can console yourself that life’s like that, as you take a good bite of gravel and wonder if the car behind you has realised that you’re no longer on the bike.
Now I don’t want you to think that I’ve neglected Wilf’s chain. It’s had regular cleaning, even more regular topping-up of the lube (proper chain lube too - not a mineral oil that sucks up road grime), and even periodic measuring with a steel rule over ten links (should be bang-on 10″)
Just not often enough or accurate enough on the measuring.
When Wilf was checked in to the bike shop a couple of weeks ago to investigate a noisy rear axle, the prognosis was terminal. To quote the report:
The reason the bike is making a noise is that the rear wheel, and the whole of the drivetrain is completely worn out. The bike needs a new rear wheel, chainset, chain, cassette, rear mech, and new cables. The cost of parts would be £230.00 [plus labour]
The thing is, Wilf’s only a cheep bike - one that I’m comfortable leaving locked up outside, safe in the knowledge that there are other shinier bikes nearby for some theiving scroat to sidle up to. A brand new like-for-like replacement Revolution Courier would be £293, or for around double that (funny how that happens), I could get a Pashley Roadster Sovereign. Or a WorkCycles’ Secret Service.
So how to prevent this happening again? This little doohicky’s the solution. It’s a go / no-go chain wear tool. You use it to check the chain wear - when the elongation’s 0.75%, think about replacement, and when it reaches 1.0% replace at once. Simple but effective - even a complete eejit like me could manage that!
The cost of this tool? Less than £8, which would yield a saving of somewhere over £280. Not a bad return on investment for such a simple tool.
Reminds me of the story . . .
For the want of a nail, the horse threw a shoe
For the want of a shoe, the horse went lame
For the want of a horse, the king was slain
For the want of a king, the kingdom was lost.