25 November, 2014

Digital Calipers, the most useful tool in the shop

by Scott

I'm the customer service guy here at VO. Odds are if you call or email us, I'm the person who will answer your question, solve your problem, or suggest a web site to look at. Looking back at the questions that we are asked, one item that would help a lot of folks answer their own question or at least have a good starting point, is a set of digital calipers. All of us here have a set on their desks. I use mine multiple times over the course of a day to measure things for customers or just to get a perspective of how large or small something is.

Digital calipers are the modern day evolution of Vernier calipers.  You can use these to measure the outside width of a bar or the length of an axle or the diameter of a seat post. They have smaller measuring jaws on them so you can measure the inside diameter of a bar.
When measuring headsets and bottom brackets, they are invaluable. You can quickly determine if the bottom bracket is French, Italian, or English. You can see if the stem is French or English sized and determine the crown race diameter to see if you need an English or JIS headset. You can measure how wide your tires are mounted on your rims, so you can determine the correct fender size.

The digital calipers can be converted at a push of a button from metric to inches as a decimal or as a fraction, thus allowing for easy conversion from one to another. There is also a set screw on the top so that you can hold a measurement if the reading is turned away from you.
A trick to ensuring correct measurements is to always push the jaws together and zero the measurement out first thing, so that you are sure the measurement is correct.
After a while, you'll find uses for this tool outside the bike world- want to see what size tubing or pipe you have in the laundry room? Use the the calipers to measure them. You'll look like a genius at the hardware store when you can ask for the tubing using the ID and OD without hesitation.


tim said...

calipers don't always tell you what you need to know. i measured a stem quill and it came out to 22.11mm. is that french or english?

Preston Grant said...

Thanks for the reminder. I have the old-fashioned Vernier type, and have
been meaning to get modern, digital ones for a long time. BTW, have installed the new Facette fenders on my '74 Jack Taylor Clubman. They look great!

Kymbo said...

I can't speak for these Park Tools units, but I'd recommend to anyone who's considering some digital calipers to ensure they get a pair with the Auto-Power off feature.

My first pair (albeit pretty cheap Fleabay specials I admit) were functionally fine, but if I neglected to turn them off and then put them away in my tool box I would often have then replace the battery if left for a little while between uses. Most annoying.

VeloOrange said...

These do have the auto-off feature. Turns off after about a minute of non-use.

Lots of bikes had that size during the bike boom of the 70s and 80s. Not uncommon to see a slightly undersized quill, hence 22.1, but it should be a 22.2. Measure your steerer to make sure. This is why we have calipers!

philcycles said...

Don't buy cheap calipers.
The LCDs die in a short time.
I'd say buy Starrett but they're so expensive.
However, they don't die so...

Terry LC said...

I like dial calipers myself, but many like the digital kind which usually can switch between inches and millimeters. But in either case, they are a very handy tool.