The spokes are often the last part of a wheel that anyone thinks about. Well to us here at Craftworx, it is a vital part of the wheel! We will cover the different type of spokes we use another time, but once the spokes have been chosen and the wheel has been laced, it is important to get the correct balance and spoke tension.
Traditionally wheel builders go by feel as to how much tension. Some squeeze, some even pluck the spokes like a guitar and listen for the tune the spoke makes. We prefer numbers... calibrated, accurate numbers!
Above: P&K Lie Digital Tension Meter
Tension is measured in Kgf, not something that this device can measure, so it measures the deflection of the spoke, or in other words, how much it bends. The trouble is, all types of spokes 'bend' differently. Imagine the difference a 2mm thigh 14 gauge spoke bends compared to a flat bladed aero spoke that is only 0.9mm. even different brands of aero spokes will give different readings!
So for each wheel build the spokes lengths are measured and cut using our Morizumi Spoke cutting and threading machine and then we use these spokes to calibrate the tension meter. A spoke is put into the device shown below and we take readings as the tension is increased. That way when we are building a wheel, we know exactly the tension that is in that wheel!
Above - The P&K Lie Tension Meter with our Tension Calibrator
Tensions can then be tailored to suit the rider, riding style and match the other wheel components to give the highest quality build. It is a process that takes time, but it is a vital one!
Above - The tension meter in action showing 2.32mm deflection that is actually 100kgf