This is an accurate tool that is consistant.
Agreed, Dave. It's plenty good enough to find a ferefnce point to pitch chains (pun? <groan!>) in the trash. The issue for me is forcing myself to trash them even earlier. I believed the 1% stretch limit was acceptable for 10-speed chains. I've come to the conclusion that it is too far to prevent premature cassette tooth wear.
Firstly, talking about whether the body of your chain checker is stamped, forged or CNCed or made from the beak of a Peruvian wood duck has no bearing whatsoever on how useful, how precise or how accurate the tool is.
Actually, it does. The die-punched edge is neither flat, regular or conducive to accurate measurement. Further, it is more prone to wear than a flatter, wider surface. A ground surface is a better gauging surface than a W.E.D.M. surface, which is a better surface than a laser cut surface is a better gauging surface than a milled surface is a better gauging surface than a stamped-coined gauging surface is a better gauging surface than a plain stamped edge. Lastly, as the punch and die wear over a production run and between sharpenings the size of the part produced will vary. Only thou or two...but we are being pedantic, aren't we? Edge form into the die clearance (10% of material thickness or theae abouts) will also vary.
BTW, where can I buy some Peruvian wood duck beak? I want to send some to Campy and have them make me an 11-speed downtube index shifter set of it.
But I'm a pedant and I can't resist the temptation to correct a few misconceptions inherent in some of the above posts.
Familiarize yourself with comparative readings. Pedantic or not, it works just fine. If you can precisely locate the zero end of your steel scale withing .005" to the centerline or edge of your chain rivet while holding it stretched and getting an accurate parallax-free reading and your eyes can actually see or interpolate .005" on a steel scale with .010" divisions...you're a better man than me Charlie Brown. I rate it a three-handed job. It's highly inaccurate, hard to repeat and the precision level sucks. But, if you are concerned about not spending more than $2 (heaven forbid you spent $5,000 on your bike!) it is plenty close enough for government work.
Inside-roller or same-side roller measurment methodology be damned, the commercial Park gauge offers me a more accurate statement of the wear state of the chain than my steel scale. God help me if I stimulated the economy by spending $11.
As an aside, a decent machinist scale from Starrett or Brown & Sharpe or Fowler costs MORE than a chain stretch tool. And friends don't let friends ride...er...buy Mitutoyo!
But the way it works means that every measurement will overestimate the degree of wear.
I only wish that were the case.
Only a few of my chains went the full 1% on my highly inaccurate, low precision, systematically incorrect gauge and I still trashed cassette gears every three, four or five chains. Maybe that's just their service life, but I don't think so. Those damned old clunky Regina Oro 5-speeds used to last multiple seasons with no skipping!
That's another point to tossing them just a few hundred miles earlier...maybe. The new gauge has a .25% reduction in wear span, so maybe it will help save the now even more narrow, more quickly worn (despite Campagnolo's ad copy) 11-speed setup. This season I'll pay close attention to the chain tool and scale readings.
(like new Shimano chains which the Park tool thinks is already at 0.5% or new Campag chains where the tool will not even fit).
WTF? Both of my Park tools fit my 11-speed Campy chain just fine.
Hey, no one can be held responsible for the fact that shimaNO can not manufacture a chain in tolerance! Both the .75% on my Park CC-3 and .50% on my CC-3.2 tools are a no-go on my (slightly in the case of the 11-speed and 1/2-way to the trash bin in the case of the 10-speed) used Campy 10 and 11 speed chains.
I'll borrow a shimaNO tool and see how well it stacks up against the Park tools.
Anyone know where I can get a discount on buying bulk chain by-the-spool?