That's step number one. A Campy chain will also measure very little elongation, even after 6,000 miles. The problem is that at that point, the rollers will be extemely worn and the side clearances huge. Most of the wear on the roller is within the holes. I made a roller spacing gauge from a 6mm hex wrench, ground to a width that will allow the 6mm wide flats to slip between the outer plates. If that gage ever goes through, your cassette is probably worn enough to cause new-chain skip, despite the low elongation. Calipers can be used to measure when the space between rollers increases by .5-.75mm.mpulsiv wrote: ↑Thu Jun 11, 2020 12:34 amDaveS wrote: ↑Wed Jun 10, 2020 11:39 pmAny tool that adds roller wear into the measurement exaggerates the elongation.
True elongation is best measured with a precision 12 inch rule.
A Campy chain can show little elongation after 6,000 miles, but if you check the roller wear and side clearance you'll find that it should have been tossed at half that mileage. Even with little elongation, using a chain for that long will cause new-chain skip.
Here you go
~3500 miles (5600 km) later with KMC digital chain checker showing 0.30mm
I use several chains in a rotation, to avoid new-chain skip, rather than having to guess at when to trash a chain.