Wheel Building: the Musical

Quando hubs and sun rims

Why build bicycle wheels when there are tons of inexpensive and well built wheel options out there in the marketplace?  Well, in this case I have been wanting a nicer wheelset for my winter bike.  It sports a mismatched and funky set that is old, pretty heavy, and is getting long in the tooth.  The bike, a 1987 Panasonic MC 7500, has 126 mm rear spacing and uses 26″ MTB rims (559 mm).  I didn’t want to spread the frame to 130 mm, and I have had these Quando/Quantum 36 hole sealed cartridge hubs that have been in my shop for a few years now.  The Quando hubs’ rear spacing is 126, and with their cartridge bearings, they should be perfect for winter riding.  Plus they are about as smooth as hubs can get.

I build wheels every now and then, so each time I do it I need a refresher course.  Since there are so many thorough, step-by-step resources available on the web, I thought I would use this post to focus on the practical side of wheel building, rather than science (Jobst Brandt), or the mechanics (Sheldon Brown).  And, not only is there a musical element to wheel-building, there is a quantum physics element as well, but more on that later.

Quando/Quanta hubs

There seems to be a bit of controversy about the quality of these hubs, but other than some sloppy machining on the spacers, everything else about them seems just fine to me.  It should only take one Portland winter for me to figure out if I have made a mistake in choosing them.  I don’t know if, because they are older, they are better or worse than newer ones.

Then, rims are needed – I chose the Sunrims CR-18 because they seemed to be priced right for my application and were going to be plenty sturdy enough for my winter/errand bike.  The cost so far: $132.

Once you’ve got the rims and the hubs, it’s time to order spokes.  Now comes the hard part.

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spocalc spreadsheet

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Freehand hub drawing and measurements

I use the spocalc spreadsheet designed by Damon Rinard.  It already has most hubs and rims built into its tables, so you may not have to take hub measurements.  Unfortunately, my hubs were not there, so I needed to take some key measurements in order to plug those numbers into the spreadsheet.  I find it easiest to make a visual drawing of the front and rear hub.  As simplistic as this may seem, it really keeps me from making mistakes at this critical juncture.  If you order the wrong length spokes, you’ll have to go and re-measure again, and sometimes you won’t know you’ve made a mistake until you are in the middle of building the wheel.  Spokes can be expensive, so mistakes can add up (Another tip:  do not pour yourself a snifter of brandy while taking hub measurements.)

You can see that the spreadsheet gives lengths for different cross patterns.  I always use a 3 cross pattern, and you can see the bias in the spreadsheet for a 3 cross pattern as well (highlighted in red).  Also, I always use 14 gauge spokes so I won’t have to stock anything but 2.0 mm nipples.

For a reality check,  I look at the output and say to myself:  are the drive side spokes shorter than the non drive side spokes for the rear hub?  Check.  Are the front spokes longer than the non-drive side rear spokes (because in this case the front hub has a smaller flange diameter)?  Check.  So far, so good.  I place my order.  That adds another $91 to the cost.  Yes, spokes ARE expensive, plus I usually order a few extras, just in case (see below).

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When the order arrives I carefully separate and label the spokes.  Then, I disassemble each packet, count them, and measure them to make sure they are really the correct length (a practice based on experience).  Then, I slowly and carefully reassemble them into their separate length packets and place them in different parts of the shop.  Do not let your spokes of different lengths congregate!  They are instigators.  If allowed to interact, all hell could break loose.  Spokes also have quantum physics characteristics.  They can change merely by being observed.  For example, once you measure a spoke, you can set it down, and when you pick it back up again, you’ll get a different measurement.  Also, spokes can be in two different places at once, and can multiply as well as disappear.  Be very alert!

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I like to work outside when building wheels – it’s kind of a relaxing experience when the weather is nice.  For resources, I follow Sheldon Brown’s wheel-building guide, and then I use Jobst Brandt’s book as a back up and technical resource.  In the photos above I have first installed the trailing spokes, with the key spoke inserted into the correct position so that the valve hole will not have crossing spokes above it, and so that the rim logo and hub logo are visible when peering down from the valve hole in a straight line.  If you read his instructions carefully, you’ll get this part right.  In fact, once you have your trailing spokes in, the rest of the spoke lacing process is a piece of cake.

I like to build the front wheel first so I can get back into the hang of it.  Since both sides of the hub flange are equal, all the spokes are of the same length.  Once that wheel is trued and dished, then I start on the rear wheel.  For spoke tension, although I do have a Tension Meter, I don’t actually tend to use it, but like to follow the musical note method (see, it IS a musical after all) of testing for proper spoke tension.  All the while I am mashing pairs of spokes together in my hands and smashing the heads against the hub.  This provides the tension relief (for the spokes, that is).

Quando/Quanta sealed cartridge hubs on 36 hole CR-18 Sunrims

Quando/Quanta sealed cartridge hubs on 36 hole CR-18 Sunrims

And there you have it.  It took me a number of hours to complete these, partly because I made an initial error on the front wheel when placing the key spoke, so had to take the wheel apart and start over.  But, the wheels look great, and I really like the way the red seals on the hubs pick up the red color on the rim logo.  Now, time for the brandy…