Notes From The Wheelbuilder

Sometimes we don't blog very much, sometimes we have diarrhea of the keyboard.  When I wasn't ignoring our motto (I raced like a gigantic idiot) this weekend, I was putting a bunch of OT into bringing our build queue down to reasonable levels.  Banging wheel builds out one after another, when you are building "the same" wheel over and over but changing variables like spokes and hubs makes small differences obvious. 

My technique for building rear wheels is that I bring all the spokes (both sides) to one level of initial tension.  This is not very much tension at all, basically I turn the nipples until they JUST over the last thread on the spoke.  Then I get the drive side up to nearly full tension, do a quick and dirty true so that I can then get the wheel round, do some horse trading between spokes to get things true and round with balanced tension between spokes, and then tension the non-drive spokes.  This brings the rim into center and allows you to true using primarily the lower tensioned non-drive spokes.  Smaller adjustments at the non-drive side have a greater side to side effect because of the greater bracing angle of the non-drive side, but their lower tension allows very small adjustments, and adjustments made at the non-drive side have a much smaller effect on radial true (roundness) than those made at the drive side. 

The big thing that's critical in that process is accurately estimating what percent of final drive side tension you want to bring those spokes to before you start bringing on the non-drives.  Basically, the longer the spoke, the closer to final value you get.  In an FSW, the centering tension of the non-drive spokes adds so little tension to the drive side that you get pretty much all the way there with the drives before hitting the non-drives.  On an 85, the drive side tensions will rise RAPIDLY with every increase in non-drive tension.  This is all basic geometry and very intuitive but as with most things if you do it again and again and again it becomes like second nature. 

I built with every kind of hub we offer this weekend with the exception of White Industries.  That's not to say that we aren't selling a lot of WI hubs lately because we are selling A LOT of them, there just weren't any in this segement of my queue.  Chris King hubs build stiffer front wheels.  They are a bit heavier than other front hubs but the big diameter, wide set flanges make phenomenally laterally stable builds.  WI have a similar geometry.  In the rear wheels, Powertap classic (current Pro) hubs have the greatest disparity between drive and non-drive tensions.  The deal of fitting those electronics into the hub means that basically you have to have a wide set, large diameter flange on the non-drive.  Novatecs and Kings build similarly in regards to drive to non-drive tensions (non-drive tension is roughly 60% of drive tension).  Kings have a slight edge here and are nice in other regards but Novatecs aren't giving much away on this front. 

One thing I am continually blown away by is how much easier it is to build with silver spokes and nipples as opposed to black.  Black spokes and nipples are painted, and that paint interferes a small but critical amount in the thread interface between them.  It's not something that can't be overcome, but the resolution available with silver will always be that bit better than it is with black.  Even after lubricating the interface between non-drive nipples and rim, and the rim/nipple interface and spoke threads on drive side, the difference remains.  I use Marvel Mystery Oil at all nipple/rim meetings and on the spoke threads at all drive side spokes and all crossed front spokes.  Radial spokes (front and drive side) don't get lube on the threads but get Loc-Tite 290 wicking thread lock installed post build.  The fronts don't really need it from a thread locking perspective but as a corrosion preventive it has some value. 

In any case, silver spokes and nipples turn more smoothly, which gives me greater resolution for small adjustments.  In the case of silver CX Rays, I've got no problem making a 1/12th of a turn adjustment - the bladed spoke basically eliminates the chance of windup.  I suspect a lot of wheelbuilders prefer bladed spokes for this reason - even if some of the bladed spokes out there offer some pretty profound disadvantages in terms of weight and cross wind profile - CX Rays are the only ones we use.  DT Aerolites are also good they are just ridiculously expensive (even over and above CX Rays).  I built a set of 85s yesterday where I was just blown away by how precise it all was, and how pleasant it was to work with.  The set of 58s I built with black CX Rays just after wound up as a set I proudly sign my name to, but if I had to enter the World Championships of wheel building I'd instantly go to silver CX Rays.  Silver Lasers are moderately easier to build with than black CX Rays, you just have to be VERY diligent about destressing them. 

As I was thinking about this, in the back of my mind I was thinking about a lot of "bikes of the pros" features on sites and in mags, and how you almost always see pro bikes with silver spokes.  It's a notable thing, and I bet it's got at least some scintilla of input from the wheelbuilders in there - "look, dude, we're going to be able to do a better job more efficiently if we use silver." 

Just a few thoughts.  Back to the pile.