How much pressure to press down on the chain checker tool?
 

How much pressure, if any, do you put on your chain checker when checking chain wear?

I have the Filzer chain checker (below). If I just place the checker tool on/in the chain, the chain reports 50% wear. But if I apply a little pressure, the chain checker drops down to 75% wear.

So I'm curious. Do you just place the checker in the chain and let gravity do the rest, or do you help it along?

Thank you.

https://cimg3.ibsrv.net/gimg/bikefor...ce2a41b5ba.jpg

Measure a 12" length of chain with a good steel rule and you will know for certain. https://www.sheldonbrown.com/chain-wear.html#measure

Checking chain wear?

Oh, geez, you've opened a can of worms.

Carry that checker with you on rides with friends and ask to check their chains to begin to gather more data points. I know of no pounds of pressure spec when using a checker, but I also haven't read each manufacturer's instructions. IME far less pressure that a wheel's QR needs to seat, maybe close to or a bit less then a classic Campy NR brake caliper QR needs. Andy

In my experience, if i can push the .75% wear down into the gap between rollers with only a bit of pressure, it is time to install a new chain. If the .75% drops in with gravity alone, it might be time to also replace the cassette along with the chain.

On further thought one could devise a small weight that hangs off the checker's tabbed end to make the insert pressure consistent. With a gage (and a checker is not a measuring device it's a go/no go gage) it's all about doing the procedure the same each time. Andy

How many chains can you check before the chain checker itself needs to be replaced? We need a chain checker checker!

But as for how much force to put on that particular gauge... I'd say unless you're bending the tool or bending the chain link... more force = more accurate.

I always put the chain checker on the upper part of the chain and press with my hand on the pedal. If it drops to 0.75, I replace the chain.

I use the Park tool chain checker and I wait until the chain is nearly 1.00 and then I change the chain and cassette. I find when the chain is between 0.75 and 1.00 bicycles still perform well without any problems shifting and I do not get any skipping when pushing hard pedaling. These type of issues may begin to occur when the chain is > 1.00 so at that point I change it and the cassette.

That subject will probably get its own thread. With a poll.

Thanks for the response everyone. A little bit of pressure on the chain checker it is!

SalsaShark Your comment about the chain checker dropping down at 75% by gravity alone meaning it is time to replace the cassette and chain is bang on. On one of my other bikes I checked the chain and the checker dropped easily down to 75%. When I replaced the chain, it was skipping all over the place and I had to replace the cassette too.

On even further thought when a checker is used with a spring loaded chain tensioner (a der as example) it's the spring's tension that initially controls the amount of pressure one can apply to the checker. IME this spring tension falls within a relatively small range. Press on the checker so the tensioning device has some "play out" but doesn't bottom out. This will control the pressure on the checker to a fairly narrow range. Andy

It's probably worth checking the chain that started this thread with a tape measure or ruler. If the chain turns out to be "really" worn out, you need to press down hard with that checker.

Exactly - apply the amount of force necessary to give the result you want.

That checker is a candidate for the recycle bin. Either use a ruler and replace at 1/16" wear or a good quality checker like the Pedros or park look-a-like. Amazon.com : Chain Checker Plus II, Black : Sports & Outdoors