Friday, February 27, 2015

Musson's Professional Guide to Wheel Building: But does it work!?

My review of Roger Musson's Professional Guide to Wheel Building is very positive. But how does his advice hold up in practice? Well, I just finished building a 650B wheelset following his advice and using some of the DIY tools described in the book.

DIY Nipple driver

Musson argues that commercially available nipple drivers such as the Park Tool ND-1 suffer from a design flaw in that they lead to an initial spoke tension that is too high[1] . Musson's design, built from a cheap screwdriver or bit has a central pin 3mm long, significantly longer than that of most other nipple drivers. The idea is that the spoke moves up inside the nipple, pushes against the pin, and then disengages the driver, allowing the builder to quickly achieve the same thread engagement on all spokes. To achieve that in previous builds I had used a visual indicator: Engage all nipples to the point where the threads just disappear into the nipple. Depending on your spoke length, this may already be too much tension, and Musson's method also sounded faster so I decided to give it a try.

Crude, but it works

I started out with a drill bit, later to be used with an electric drill. I don't have a vise, and consequently the tool I produced is neither pretty nor particularly precise. Musson also advocates against using an electric drill. He argues that with a hand tool, it is easier to precisely feel get the disengagement of the tool just right. After having used an electric drill in this build, I tend to agree. I ended up with fairly good equal tension in all spokes, but it could have been better still. Another problem I encountered was that after using the tool, the spokes were still very slack, requiring several more turns with a regular spoke wrench. However, that probably was less the fault of the tool but of slightly too long spokes (see below).

Spoke lengths

I had ordered spokes before buying Musson's book and reading his strongly worded advice to not rely on manufacturer or any other measurements that you haven't done yourself. While I actually had measured at least the front hub myself, for the ERD of the rims and the rear hub I relied on the value provided by the manufacturer/the Edd online database. This did not work out so well. Assuming that my tensiometer is still accurate, in order to get adequate spoke tension, I had to engage the nipples to a point where I'm almost out of thread. One or two millimeter shorter spokes definitely would have been better—and probably would have prevented the problem with the nipple driver described above.
Spoke is already far in the nipple, despite not being at final tension yet

Lacing instructions

The lacing instructions were perfect. I got the lacing (32 spokes, three cross) right on the first try and for the first also managed to properly align the hub label with the valve hole (for purely aesthetic reasons, one is supposed to be able to read the hub label when looking through the valve hole). Between the written instructions and the helpful illustrations it is hard to go wrong.

Dishing gauge

When reading the instructions for building a dishing gauge, I was skeptical: Building a precision tool out of cardboard, double-sided sticky tape, and zip ties!? But lo and behold, this is a very solid design. Instead of using Musson's design of a bent spoke as the feeler gauge, I simply stuck a barbecue skewer through the corrugated cardboard. Because my truing stand—in contrast to Musson's design or the Park Tool TS-2.2—requires me to have the quick release skewer in the wheel for truing, the BBQ gauge was not ideal, requiring me to remove the QR skewer each time I wanted to check the dishing. This would be easily fixable, though, and with the QR removed, the dishing gauge worked great! As an alternative to cardboard, Musson suggests using thin plywood. At this point I think that for an infrequent wheelbuilder like me the (more easily manufactured) cardboard version is totally sufficient. Instead of using double-sided tape to attach the wood pieces that sit against the rim, I used superglue, which allowed me to more easily align.

I used E-6000 glue instead of double-sided tape to attach the wood pieces


Spoke torsion flag (and marked valve hole)
As a way of achieving spoke tension, Musson, like others, suggests using the sound a spoke makes when plucked with a fingernail or guitar pick: Pluck the spoke and compare the sound to that of the other spokes. I must say that this has never worked for me. You always get a mix of different frequencies and I find it hard to compare them to each other. It's quite possible that this is just a skill I lack (I do like death metal and grind core after all...), but I rather relied on my Wheelsmith tensiometer. Of course, as Musson correctly points out, this is more time consuming than the plucking method, but it does have the advantage of also providing you with absolute values for the spoke tension.

Musson's approach of iteratively checking lateral trueness, vertical trueness, dish, and tension works well, especially if you have the luxury of the amateur wheelbuilder: You can take as much time as you want to. For the final stages of tensioning I found his advice of using a masking tape flag to visualize spoke torsion to be especially useful. Under high tension, turning the nipple will start lead to a small amount of twisting of the spoke instead of further engaging the threads. So if you turn the spoke half a turn, it will probably only have engaged the equivalent of one third of a turn earlier in the building process. Previously I had just overtightened the spokes by about one eight of turn and then turned them back the same amount to get rid of the spoke torsion. But with the flag method it is possible to get the exact amount of required overtightening and backing out.


All in all, using Musson's tools and instructions allowed me to build a great set of wheels with little pain. Obviously I can't say for sure how they're going to hold up in the long term. But the tension is even, and trueness and dish are within tight tolerances so that I have a lot of confidence in them. The Professional Guide has proven itself to be an excellent manual for wheelbuilding while also saving you money by building your own tools.

[1] I believe this is not true for this VAR tool. But then that's 50 bucks...

Wednesday, February 25, 2015

Building wheels, building wheelbuilding tools: Roger Musson's Professional Guide to Wheel Building

For Gunnar's 650B it was about time to actually build wheels. I had accumulated the components over the past two months from various sources. At this point I have built somewhere between five and ten wheels, and they all held up very well. As I'm an optimizer-at-heart, though, I wanted to try something new this time and therefore bought Roger Musson's “Professional Guide to Wheel Building.”

In discussions about wheelbuilding, I had frequently heard about Musson's book. However, between the canonical “Art of Wheelbuilding” by Gerd Schraner and Jobst Brandt's “The Bicycle Wheel”, Musson is generally the lesser known. I myself have read Brandt and didn't like it much because of its more theoretical-technical approach. For step-by-step instructions I have mostly relied on Sheldon Brown's (and now John Allen's) online instructions. Those I found sufficient yet not ideal: The instructions are obviously clear enough to have allowed me to build up a number of wheels over the years. But it wasn't always a smooth process, for example several times I had to un- and re-lace wheels because the valve stem had ended up in the wrong spot.

Musson's book is clearly written from a practical perspective, drawing from his experience as a professional wheelbuilder. He often quips about how there are ways of doing things different from the ones suggested by him, but that more often than not they in the end all result in wheels that work.

After a quick introduction and outline of the book, the first substantive chapter discusses the different components of a wheel and the key concepts relevant to building a wheel. Supported by a number of helpful illustrations and photographs, I found this chapter to have just the right amount of detail both for first-time and more experienced wheelbuilders. Once again, the pragmatic approach becomes evident in the discussion of where to put pulling and pushing spokes, a topic that has inspired much heated discussion and little consensus over the years:
For your first wheels lace them as Option A ... For your next set of wheels lace them as Option B. If you are a disc brake user, then lace your third rear wheel as Option C ... By doing this you will understand how to lace the different options and have proof that they all work the same. (p. 32)
The following chapter then discusses the different options for building a wheel, for example how many spokes and which lacing pattern should be used for which application. Chapter 6 is probably the most unique among wheelbuilding books. Here, Musson discusses the tools needed for building wheels. But not only does he discuss commercially available tools; he also provides detailed instructions how to build a nipple driver, a wheel dishing gauge, and even a truing stand. So far I have built the former two, and I agree with his assessment that they are equivalent or even superior to their commercial counterparts such as the Park Tool WAG-2–and certainly much cheaper. I have read similarly good things about the design of his truing stand and will probably build one myself at some point.
Almost completed dishing gauge

Determining the correct spoke lengths is discussed in its own chapter. Musson strongly advocates for not relying on manufacturers' numbers or ones found on the internet. Instead he describes in detail how to measure both hubs and rims and consequently calculate the correct spoke lengths (an online calculator is provided on his website). At this point, the reader should have all the ingredients required and be ready to start actually building the wheel, which is discussed in the following two chapters. Chapter 7 discusses lacing the wheel. Musson's instructions here are very easy to follow, and for the first time I was able to effortlessly lace a wheel correctly on the first try, even getting the "read-the-hub-label-through-the-valve-hole" thing right. Tensioning and truing the wheel is the topic of chapter 8. Through my volunteering at a community bike shop, I'm much more experienced with truing and tensioning than with lacing, and therefore a lot of the information presented by Musson wasn't new to me. Still, he offers a lot of little tips and tricks borne out of many years of building experience, for example using little “flags” made out of masking tape to make spoke torsion visible.

The final substantive chapter discusses repairing existing wheels, dealing with broken spokes, worn rims, or shot hubs. Chapters 10 and 11 provide a few additional illustrations and a one-page wheelbuilding checklist.

An additional strength of Musson's book is its publication method: Musson self-publishes the Professional Guide as a PDF file without digital rights management. In contrast to many other e-books, this allows reading the book on many different devices and also easy printing. The typesetting and image resolution is very good for a self-published book. An additional advantage related to this way of publishing is that it allows easy updates to the book. Its first version appeared in 2005, and the book that I bought is already the sixth edition. Compared to Brandt and Schraner, it is apparent that Musson takes into account recent developments such as off-set frames and rims popular with fat bikes. Buying one copy of the book entitles readers to all future updates and also to access to a website with additional materials and a support forum.

All in all, Musson's book is excellent, and I wish I had bought it earlier in my wheelbuilding career. I highly recommend it to both novices and somewhat more experienced hobby wheelbuilders who are primarily interested in building wheels-that-work without necessarily caring about the finer theoretical details of the process. Wheelbuilding as craft, not science or art.

Roger Musson, The Professional Guide to Wheel Building, 6th edition. Self-published e-book. 115 pages, £9 ($14 USD).

Thursday, February 5, 2015

Save Wisconsin's bike funding and Complete Streets!

From the Wisconsin Bike Fed blog:

The governor’s budget (Senate Bill 21) would:
  • Repeal Wisconsin’s successful Complete Streets law. The law requires that bicyclists and pedestrians be taken into account whenever a road is built or reconstructed with state or federal funds. There are all manner of ways to get an exception if the project would be too expensive or if use by bikes and pedestrians is projected to be too light. The law works well in practice. Yet, the governor chose to eliminate it altogether. This would mean many fewer safe places to bike.
  • Cut the Transportation Alternatives Program by $2 million. The governor would eliminate all state support for this program, leaving only federal dollars. TAP is used for a variety of pro-biking initiatives, including bike plans and facilities.
  • Essentially eliminate the Stewardship Fund. The Knowles-Nelson Stewardship Fund (named for iconic Republican Governor Warren Knowles and Democratic Governor and Senator Gaylord Nelson) works to purchase and protect land for future generations. Funds for state trail purchases are included in the program. The governor would stop all purchases for over a decade.
 If this proposed budget were implemented, it would be a terrible step backwards for cycling and walking in Wisconsin. Complete Streets has been a successful instrument to provide amenities and allow access for all street users, not just people driving. Repealing this requirement is shortsighted and will make Wisconsin a less livable state. Streets only get rebuilt every 20 to 40 years, and therefore even if Complete Streets requirements were to be introduced some time in the future, the damage already would have been done. So please take some time and write to your state legislator or the governor to make your voice heard.