SquidPuppet

Uh oh. Can the same thing be caused by very sweaty hands during a build? I recently laced a pair of wheels and during the process my fingers and the spokes/nipples became very blackened. Once complete, I wiped everything down really well, but still.........?

FBinNY 

Nothing to worry about. Chloride damage in stainless steel takes some time, not minutes or even hours at room temps. It also requires higher concentrations of salt than your sweat, unless you repeatedly sweat on the part, let it dry and sweat some more (why rollers and trainers can be so hard on bikes)

Also, it doesn't appear as general blackening of the surface, but as small black pits or veins as the attack penetrates the crystal structure.

Generally bicycle spokes are resistant (not immune) to chloride damage, but every once in a while a maker will use the wrong alloy or process making the spokes vulnerable. The damage usually happens within one winter season, and most if not all the spokes will be affected. A few years back, a problem batch was used by a number of bicycle companies, and dealers who remember will tell you that the vast majority of wheels with those spokes needed replacement within a single season as the spokes became about as brittle as dried spaghetti.

SquidPuppet

Thanks FB. It's weird too, because it has never happened to me before and the amount of film that developed was significant. I was worried that I may have set some odd chemical reaction into action.

FBinNY 

Next time wash your hands before lacing a wheel.

chriskmurray

I have never tried that, I just tend to release the handle relatively quickly and do it at the same speed for every spoke. I do have the luxury of a higher end tension gauge that is not really affected by user input that I calibrate both the park gauge and myself to get the right reading. One other thing that is nice but not really an option for a lot of people is to build a calibration jig with a strain gauge and the type of spoke you plan to build with set at your desired tension.

FBinNY 

It's very easy to calibrate any spoke tension meter if you have a tree, tire swing (or rope), some metal brackets, and a few friends weighing close to 100kg, ie. 90, 100 and 110kg. Basically use the rope and brackets to hang the swing, so a spoke and nipple can be fitted mid-line. Have the friends sit on the swing, and take the tension readings. This is cheap, easy and, as a "dead weight" device, just about the most accurate way to calibrate the instrument.

OTOH- people ask too much form their tension gauges. There are any number of fast and easy ways to verify even tension, and these are much faster in practice than measuring each spoke. For absolute tension, consider that the measurement doesn't have to be more accurate than the method that you used to determine the target tension. Since just about everybody uses a ball park range for the goal, you only have to measure well enough to hit the ball park, not any one place within the ball park.

chriskmurray

Never thought of using friends as calibrations weights, not a bad idea! The main reason I have never liked this method was never having that much dead weight around so that is an easy solution to that problem!

I personally like the idea of accurate and consistent gauges for tension. I like it mostly for repeatability not so much for even tension because realistically if you do it right there should be little to no correction for tension balance anyways although a second check to make sure that is the case is always nice. I personally have never had the most fine touch so that may be part of it though.

One thing I do really like about the Park gauge over my much more expensive Wheel Fanaytic gauge is it is very very fast and surprisingly consistent with my more expensive gauge after playing with both to calibrate myself to the higher end gauge.

FBinNY 

Nothing like dead weights that can walk around on their own.

+1, IMO, this is the right use for the tool. BITD, most of the wheels I built were basically the same, or so similar that I cold consider them the same. As such it was easy to maintain my finger calibration. These days there are so many different rims, spoke counts, and other variations that I need to check and verify that the wheel is where I think it is. But I don't obsess, if it's within the range, a few kg tension either way is fine. I'll typically take 2-3 readings on either the right or left side depending on what I'm more concerned about, and figure the average is the "true" value. I usually do this near the end of the tension loading process, so I can adjust the final tension loading accordingly, rather than wait until I'm done and get surprised.

Based on this, I'm not overly concerned with the gauge being a precision instrument, A- because it really isn't, and B because I don't depend on it being one.

BTW- I use an old Wheelsmith unit, which seems to be very repeatable.

Dan Burkhart 

I built a calibration fixture, and I find it invaluable as I use my Wheelsmith tension meter a lot, and building a branded line of wheels, I require consistency across the board. I want a wheel I build today to be the same tension as one I built a year ago was when it went out the door.
My calibrator caught the attention of Roger Musson. He mentioned it on his blog. Scroll to the bottom where it says calibrate your own tension meter.
Wheelbuilding spoke tension and tensiometers

chriskmurray

That is where I am now, the majority of the wheels I build are nearly identical. I have built so many of them I can tell you exactly how many turns on each side after running the nipples in to have the wheel almost perfect as far as tensions and dish goes.

I guess my Wheel Fanyatic gauge is the "modern" Wheelsmith gauge as it was made by Ric Hjertberg and I think he built the original Wheelsmith gauge as well since he was co-founder. Both work very well in my experience.

Scooby Snax

OK

I figured out how we went wrong last time, just to be sure I did it again. Laced the wheel up and then realized I rotated the hub the wrong direction which didn't put the valve hole between parallel spokes.

I will be doing a tutorial on "wheel building the wrong way" for anyone who wants a comprehensive insight into the joy of Guinness, wheelbuilding and dyslexia or RFVH for short.