Originally Posted by
iketurner443
2.3/1.8/2.0mm
what does that mean
That's the diameter of the spoke. It has a 2.3mm head, narrows down to a 1.8mm middle section and, finally, has a 2.0mm end where the threads are. OEM (Original Equipment, Manufacturer) wheels usually come with 2.0mm that are the same diameter along the entire length...often called a "straight gauge spoke". Double butted spokes will have be 2.0/1.8/2.0mm. The thinner middle section actually gives an increase in strength because it is elastic and can stretch some. A straight gauge spoke will transfer the stress from the end to the head without as much elasticity and is there for more prone to breaking.
The link I provided discusses what the 2.3mm head gives you over a double butted spoke. It greatly increases the fatigue limit on the bend and makes the spoke much more durable, especially for heavy loads.
Sorry about this but I'm going to go very nerdy on you.
Pillar Spokes have charts that show the strength of various spokes based on the gauge and butting. The chart below shows the breaking point of straight gauge spokes (the P14 is a 14 gauge spoke which is 2.0mm in diameter)
Image 5-11-18 at 1.41 PM by
Stuart Black, on Flickr
You can see that the spoke breaks at 270 kgf. The unit doesn't matter. Just look at the magnitude. The next chart shows a double butted spoke that is 2.0/1.8/2.0mm (14/15/14 gauge)
Image 5-11-18 at 1.44 PM by
Stuart Black, on Flickr
The double butted spoke breaks at a higher force (about 300 kgf) which translates to a more durable spoke. It's 11% stronger. A triple butted spoke...in the case of Pillars, they are 2.2/1.8/2.0mm (13/15/14 gauge)...breaks at an even higher force as seen below
Image 5-11-18 at 1.43 PM by
Stuart Black, on Flickr
The "2018" is the one I'm talking about and you can see that it breaks at about 340kgf. That's a 25% increase in strength over the straight spoke. Pillar makes a quad butted spoke that has a 2.5mm head, a 2.3mm bend, a 1.8mm middle section, and a 2.0mm end. I don't have the graphic for it but you can find it
here (Homework for ya
). The breaking force needed is whopping 410 kgf. That's a strength increase of 51%.
The only problem with Pillars is that they are hard to find.
BDop Cycling carries the triple butted ones. I haven't been able to find a source for the quads. DT Swiss makes the Alpine III which any bike shop should be able to order through Quality Bicycle Products (QBP). They are 2.3/1.8/2.0mm spokes and a little weaker than the Pillar Quads. I've seen calculations that say the Alpines are 48% stronger than 2.0mm straight gauge spokes. That's nothing to sneeze at.