OMG, some of the stories I could tell about spoke lengths. You think there are rules about spoke use? Length precision? Optimal cross patterns? Gauge choice? Replace or re-use do's and don'ts? Fugetaboutit.
None of these matters as much as having a working wheel. And scarcity will drive some interesting solutions. When I started out building, spoke supplies were terrible. The Schwinn empire was crumbling and their stocks of Berg-Union (Germany) spokes were full of gaps. You could get nice straight and butted spokes, but galvanized. The few chrome plated ones quickly rusted and the chrome process embrittled the metal. Try building from inventory measured in inches, every 1/8" from 11 to 12-1/8.
Robergel (France) was available from some specialists but only in butted 15 gauge. Pretty thin for MTB or tandems. In the Bay Area, we were lucky to have the dynamic of Spence Wolf and Phil Wood. Phil made great hubs with unexpected dimensions but any drilling you could name. Spence imported Robergel in as many lengths as he could stock. Wheelsmith got its start by buying obscure spoke lengths from Spence. How proud we were that you could get the length for high flange Campagnolo track hubs laced radial to a standard tubular rim. Hey, it was a big deal.
Initially, we were lucky to have a few lengths in each range. Later, stocking even numbers was ambitious. So it was time for a spoke length calculator. The math is simple and ancient but convenience was needed. Jon and I grabbed a hand held calculator, first a Sharp. Back then (late '80's) such devices were like magic. And expensive. With programming help from Eric Topp (Stanford student racer, later engineer and designer), we unveiled the World's first Spoke Calculating System.
Why such a creation? Not to blaze a trail of innovation in wheel design. No. It was born of the necessity created by scarce spoke availability. You always had to use a compromise length. With short, racing nipples, errors couldn't be more than 1mm or you had an embarrassing bunch of threads on view outside the nipple.
A spoke calculating system told you the exact length needed so you could use the wrong length with confidence. If it's going to be short, make sure not too short. If there are none for X3, then quick calculate X2 or X4. Maybe you have those. We built wheels with miss matched spoke gauges and crossings as often because we didn't have the right length as because we were doing some intelligent design.
Ha, those were good times. How about double crossing? I mean an over-under tuck, twice between hub and rim. Absorbed 1mm. I remember a wheel set with skinny, attractive Stella spokes (Italy) where double cross made using 302's possible. How else would we find out if X2 worked? Eventually spoke calculation became a given.
With all the asymmetric thinking of a fast-emerging bike scene, Phil Wood came to the rescue with his spoke cutter and threader. Now bike, hub, and rim makers could let it rip. Calculate the spoke, cut it to length, and any combination could be built. Wow, like the light bulb! The scene really started to boogie.
How else could innovators like Tom Ritchey, the WTB scoundrels, Bontrager, Specialized, Gary Fisher, Santana tandems, and those HPV's of land speed record fame do their memorable work? By the early '80's we could support MTB's, funny bikes, and the 24" wheels of the 1984 Olympic Team. Sky was the limit and Scott Gordon and Andrzej Bek start making bladed spokes. Aero rims from Araya (JP) and Saavedra (Argentina) were welded and re-drilled to ultra low numbers.
Just remember, there is no "right" spoke length or pattern or gauge. It's the one you can make work. Necessity is the momma of invention. Could all of triathlon, MTB, aero, tandem, and suspension come from a scene that wasn't accustomed to rule breaking, that didn't learn during times of scarcity? When it comes to wheelbuilding, don't get too holy about rules and correctness. You are enjoying a scene built on poverty driven problem solving.
When things don't exactly match up, sit back, reflect. Maybe there's lemonade to make. No telling where it might lead!
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Bern
November 02, 2021
Hi Ric -
Long time…
I’ve been thinking about spokes (a little – I mean who has the time?? Oh…right…)
When we started testing the finished product coming off the backside of the spoke machine we were perhaps overly pleased at the results:
• consistent optimum thread shape
• consistent thread length
• Consistent spoke length…hmmm…well, yeah, spokes accurate +/- 0.1mm…but what is the standard tolerance…?
I started measuring entire 500-spoke boxes from several of the industry-leading fabricators. I found spokes as much as 2mm different (short and long) from the labeled length on factory sealed boxes. Were other wheelbuilders measuring all the spokes they took from a new box to make certain the lengths were as marked…?
I dunno, but I did start telling mechanics about the accuracy of the length we were holding.
But another nagging thought keeps me wondering about the bigger picture: if all mechanics were counting on the labeled length, but were in fact using spokes of considerably inconsistent lengths, and yet still churning out thousands of pretty damn good wheels, then were we perhaps worrying too much about it? Phil counted on what he called the “intelligence of the materials” to sort out much of the mechanical mystery…he also often said “Fret not” …
Words I try to live by…
Cheers -
Bern