vredstein

Buying a 12" ruler is like special ordering exactly 32 spokes.

DOS

I use my park spoke ruler -- not much beyond 12 inches but it includes 1/4 inch of ticks in 1/16th increments past the 12 inch mark so plenty to work with.

https://www.parktool.com/product/p/sp...er-gauge-SBC-1

FBinNY 

There's nothing magic about measuring over 12". It's convenient, given the length of the upper or lower loop chain lengths. And it makes for easy math since 1/8" over 12" is so close to 1% stretch.

But if the ends of a 12" ruler are a bit beat up it's easy enough to measure over 11-1/2" measuring from the 1/4" mark, to the 11-3/4" mark and having the markings from 11-3/4" to 12" to measure against.

Amesja

Spend $10-15 on a new chain.
Spend $10-15 more on a Park Chain GO/NO-GO Gauge.
Spend $10-15 more on a chain tool.

$30-45 can't hardly fill up a car's gas tank. The cost of riding is much less than driving. But there are some costs.

Don't let it get so bad again.

Hopefully you won't have to spend 2 or more times that for a new freewheel/cassette and chainrings. That is being penny-wise and pound foolish. You aren't the only one who learned this the hard way (including me).

davidad

https://www.sheldonbrown.com/brandt/chain-care.html To lube my chain I use a mix of 4 parts unscented mineral spirits to 1 part chainsaw bar oil. I remove and clean the chain every 650 to 700 miles to service it.
I don't think much of the purple lube.

Amesja

Chains are like what? $10-20?

What are we going to do next? Take the tires off every week and turn them inside-out and scrub them with scented bath oils in the tub to get an extra 10 miles out of them?

Removing the chain every month to clean it is approaching this in the silliness quotient.

Anthropy

Using a wood ruler is not good for measuring that close anway. I use a metal tape measure. One trick is to not start with the first mark, but start at the 1 inch mark and then measure to the 13th mark. You are still measuring a 12 inch span, but the first mark is more defined.


Tom

Scooby214

This is very good advice. I teach my fourth grade students to measure from the 1" mark for the same reason.

FBinNY 

How close is "that close"? A wooden or even a cheap plastic ruler is accurate enough for the purpose, since we're talking an eyeball measure of something that isn't digital. There's nothing magical about replacing a chain at precisely 1/16" stretch (or any other point). The precision of the measuring instrument therefore is non-relevant (unless you're someone who stops and looks for a gas station to do an oil change when your car's odometer ticks over exactly 3,000 miles).

Since the exact replacement point is somewhere within a band, measuring it precisely is meaningless.

I do agree about using a marked reference rather than the worn end of a ruler, but many rulers have a bit on waste beyond the 0 and 1" marks so you can start at zero, or you can use any mark any pair of marks at 1/2" intervals, 1/4 & 11-3/4" or 1/8 and 11-5/8" or whatever works for you.

I wouldn't post this, but some people make chain measurement seem more complicated than it is, which causes readers to buy devices in search of more ease or accuracy. That's a shame, because the devices tend to be meaningfully less accurate, and users often waste dough replacing chains that still have as much as 1/3" of their usable life in them.

While many insist you need a ruler longer than 12" or a precision steel ruler, or anything specific, my point is that virtually anything is good enough for the task. I personally prefer something that doesn't overhang too much, because the available space on some of my bikes is a bit tight.