Correctly Measuring Spoke Replacement Length?
 

27" vintage wheels.

Any given spokes on the rear wheel measures out 310mm max, but more like 307mm to the inside beginning of the J bend. So if I am looking for threaded replacement spokes, am I looking for those described as 305mm or 310mm?

Thanks much.

Not sure where exactly you get 310mm and 290mm, most nipples are 12-16mm long. But the spoke length is generally considered to be from the end of the threads/spoke to either the inside of the elbow or to the center of the spoke at the elbow. This difference is only 1mm typically, well within the range of common wheel building tolerances.


When measuring a spoke still tensioned in the wheel it's easy to think the spoke is a couple of MMs shorter then it really is. Between the slightly curved path an interlaced spoke takes from the hub to the rim and the tiny bit up/in the rim I add 2 or 3mms to a inside of rim measurement.


When I cut spokes for touring spares (for others) I'll usually go on the short side of the various fudge factors that make up a measurement. I'd rather see a few less threads of engagement (yes the nipple is taking all the stress at it's head) then see a spoke stick up too far and either not let the nipple fully thread on or increase the chance of a spoke poke to the tube (after rim strip R&R). Andy

My misprint, the difference I'm measuring is in the 2-4mm range. Yeah, I've noticed some measure from the inside beginning of the curve, but there are some sellers that measure to the head of the spoke. I guess either would be within the fudge factor...and poking against rim tape would be the worse scenario.

A spoke ruler works quite well.
https://www.amazon.com/Park-Tool-Spo...rk+spoke+ruler

If you look at the ruler above, note the "tear drop" shaped holes- You hook the bend in that, so you can see how a spoke is measured- Inside the bend to the end.

Depending on the wheel/hub set, you may have 3 different lengths.

Just take out the spoke in question, measure it and put it back in.