Seems to me that there might be more than .5% visual error in trying to use a ruler (even a steel one). Movement, visual angle, etc. would affect the reading. How do you do it and still ensure accuracy?
I have a caliper that can give me fairly accurate readings but even that can be problematic (like how to get 2 appropriately relative points to measure....like the same position on the 2 links used for measurement).
Originally Posted by
HerrKaLeun
I would stay away from most chain checkers as they don't account for roller wear. For example, the Park tool shows me 0.25% elongation for a brand new chain while my ruler shows me exactly 12" (as Expected). so yes, brand name chains should start out exactly at 12" for 12 links. Shimano and Pedro's make a chain wear tool that correctly takes roller wear into account. the ruler has to be steel, not plastic or other material (same expansion coefficient so the chain and ruler will be the same when cold or hot). So with one of those cheap chaintools you replace the chain too often. That may not be bad, but be aware.
I have 10 and 11 speed drivetrains, so my "cheap" parts are already above bottom of the barrell. I don't know if a chain twice as expensive lasts twice as long, but the cheap chains also last thousands of miles in road use when maintained. A lot of anecdotal evidence,...
You don't have to measure frequently once you kind of know how long they last to 0.5%. Maybe monthly or so.