Wattsup

I want to check my rotors to be sure they meet minimum thickness. There are tons of inexpensive electronic calipers available on Amazon, but I thought I'd check here first. I see the ones that have probes that look like pliers, flat surface, and I also see the ones that come to point. Seems to me the ones that come to a point would be best for measuring something flat like a rotor, no?

The one's with points have long arms, so I also wonder whether they're likely to get hung in in spokes.

What are you all using?

Thanks..

mdarnton

Something like this is fine and they have plenty of room to get in where you need to go:
https://www.ebay.com/itm/274400814814
Plastic may seem cheap, but this type is actually pretty good. If you feel fancy spring the ten buck for metal ones.

Something where the contact surface is a point is not good because rocking the calipers around will cause you to measure diagonally through the disc, which will give a false reading, too thick.

dsbrantjr

A problem with using a caliper is that there may be a lip around the edge of the rotor which may be difficult to get around to make the measurement. An inexpensive micrometer or even a "Gauge-It" may be a better way to go: https://www.ebay.com/itm/23398501619...oAAOSwxZZgiAcc https://www.ebay.com/itm/22440372831...MAAOSwAktgYN84

Iride01 

Calipers should work. Just make sure to get the edge of the disc into the relief of the jaws. A micrometer will eliminate all worry, but mic's are more accuracy than is needed for this.

Wattsup

I bought this one. I think it hits the sweet spot for my purposes. It has 4.5 stars on Amazon, and the reviews seem consistent. https://clockwisetools.com/products/...=5455899525149

Wattsup

Just wanted to update. After further deliberation, the micro I finally decided on was this one, rather than the one from the Far East. It's manual Mitutoyo in metric, measures to the hundredth of a millimeter. Only $50. It's a really quality tool, one which I'll probably pass to my heirs. Although I forget exactly when I last replaced the rotors, I know I did it within the last 2-2.5 years. I use metallic pads on Shimano 160mm Icetech, and they're pretty worn down, 1.6mm on the front, and 1.53mm on the rear. I ride in a lot of dirt, often wet dirt, so I guess that's why they wore so quickly. New is 1.8mm, and 1.5mm is the minimum...time to replace. I thought it interesting that the rear wore faster than the front, but then I remember that I used to think it was a good idea to use the rear brake near-exclusively on dirt. That's changed after I learned the hard way that the rear brake is almost useless on gravel, packed dirt, when you're going down an incline (decline?), even a very shallow one. That lesson only cost me a cracked rib. 😜


https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1