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

Tensioning

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.

Conclusion

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...

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).

Measuring the SP PD-8 hub

UPDATE January 2015: You can now find a technical drawing with measurements here.
CORRECTION: Please note that an earlier version of the post claimed that the center-to-flange distance is 32mm. I've corrected that to 22mm. Sorry for the confusion.

I'm getting read to build up new wheels with my recently acquired dynamo hubs. In my previous post, I had posted the manufacturer's stated dimensions, but I realized that they only provided the pitch circle diameter and the flange diameter--the latter being irrelevant for determining spoke length--but not the center-to-flange distance and also not the spoke hole diameter.

The best instructions for measuring a hub come from Roger Musson, author of a popular book on wheelbuilding. Fortunately, he has made this part of the book freely available. All you need to take the relevant measurements are calipers and a ruler. Musson suggests to drill a piece of wood, so that you when you insert the hub's axle the wood will be flush with the locknuts. If you're building a lot of wheels this probably makes sense. As an alternative, you can just measure from the end of the axle and then subtract the easily measurable distance between axle end and locknut. Then use the ruler to measure the distance between the wood/axle end and the inner side of the lower flange (what Musson denotes as x). Then turn around the hub and repeat the measurement on the other side, giving you the y value. With the SP disc hub that's a bit tricky, as the diameters of the two flanges are different. Musson's suggestion is to use a small piece of cardboard, mark it, and then measure on the cardboard. I was in a bit of hurry and thus just eyeballed it with the ruler after seeing that x and y would likely be the same for this hub. X and y are not the actual values needed for calculating spoke length, but they allow you to calculate the desired value by subtraction from half of the over-the-locknut dimension of the hub, z in Musson's system. On modern front hubs for regular bikes you don't really have to measure this, as it is a standardized dimension at 100mm. For the PD-8, x and y equal 28mm (32mm-4mm for the distance from axle end to locknut), yielding a center-to-flange dimension of 22mm on each side.

The flange diameters can directly be measured with calipers. Just make sure to measure from the centers of the spoke holes. The PD-8 comes out to 52mm and 58mm. The spoke hole diameter is a bit tricky to measure: The inside jaws of regular calipers tend to be too big for such small holes. I measured 2.7mm, but as most hubs use 2.5mm holes I'm assuming this is a measurement problem.

Now you can plug your values into the spoke length calculator of your choice and voilá! I recommend Karl Stoerzinger's Freespoke or the DT Swiss calculator.

First impressions: SP Hub Generators PD-8 and PV-8 (updated)

Wouter Scholten's website is a great resource for all hub generator lighting issues. He extensively tests almost all models of hubs and lights on the market in real world settings, and he is also unusually well-informed with regard to the introduction of new products. A while ago, he wrote about a new player on the hub generator market, Shutter Precision Ltd. from Taiwan. As the name implies, they started as a supplier for digital cameras and then later moved into bike component manufacturing. While the company itself has little name recognition, they are (presumably) the suppliers for two better known companies, Velo Orange[1] and Supernova.

After having introduced their switchable dynamo (in my opinion a solution in search of a problem), at the 2011 Taipei Cycle Show SP announced what would be the lightest generator hub, the SD-8 (disc brake)/SV-8 (rim brake). These two hubs, however, only are rated to a power output of 2.4W in a 622mm wheel, making them not street-legal according to the German StVZO requirements. However, they also announced a slightly more heavy model rated at 3W, the PD-8 and the PV-8. The technical specs and the prototype tests by Wouter sounded promising, and when Wouter's shop, Gambiet Fietsen, offered them for pre-order in September I went in for two generators, one disc, one rim. The disc one will replace my Shimano DH3-N80 on the Cross-Check which I unfortunately messed up while trying to re-grease the bearings, and the PV-8 will be part of a second front wheel for Gunnar, finally allowing me to turn him into a real brevet bike.

The hubs arrived yesterday, at a total price of 180 Euro shipped. The actual wheelbuilding will have to wait for a little while longer, but I wanted to share some pictures and impressions.

PV-8 in its original packaging. I'm not sure if all the color and spoke count variants are or will be actually available.

The hub looks quite similar to the current SON 28...

...but it does have the same terminal as Shimano hubs

Here you can see the German K-certification wave, making the generator street legal in Germany

The weight pretty much exactly matches the claimed weight.

Both the disc and non-disc version of the hub match their claimed weight of 390 g and 410 g, compared to 440/460 for the new SON 28, 490 g for the Shimano DH3N80, and 399 g for the Supernova Infinity S (center lock disc mounts). Only the SONdelux at 390 g (rim) and 395 g (disc) can match this, but at a significantly higher price point.

SP claims that the new generators do not only excel in weight, but are also "the most efficient" generators (this refers to the 2.4W ones) and their product sheets has a couple of graphs that show the generators to be more efficient than the SONdelux. I'm somewhat skeptical about those claims and am very much looking forward to some independent testing.

Measuring the dimensions of the hubs is a bit tricky with the tools I have and I've only been able to find the manufacturer's numbers for the 2.4W version. Probably they're going to be the same for the 3W, but I'll confirm this with Wouter or measure myself. The bearings are sealed cartridges and I'm not sure if they are user-replaceable.

I think that's all I can say for now. Once I have the wheels built up and ridden them a bit, I will post an update.

Update 2011-12-16:
In the meantime I've found the website of SP's distributor, and their catalog lists the relevant dimensions as follows:

	PV-8	PD-8 (non-disc/disc side)
Spoke P.C.D.	52mm	52mm/58mm
Flange diameter	60mm	60mm/66mm

They also have "replacement instructions" on their site that might contain instructions on how to replace the bearings. Unfortunately, the document is corrupted, though, and can't be opened. I've sent them an e-mail and we'll see if I hear back.

[1] If I remember correctly, the Velo Orange switchable dynohub got some bad reviews. At any rate, they no longer seem to sell it.
[2] There is also a 2.4W version, called SD-8/SV-8, suitable for those on small-wheeled bikes or those who don't care about the extra power/street legality in Germany.

New Front Wheel for Gunnar

I don't really have a good excuse for doing this, but I've built a new front wheel for Gunnar. As you might remember, currently he's running Wolfgang's old Alex-DA16-on-Deore 36 spoke wheel. While this works just fine, the internal rim width of the DA16 is 16.3 mm (at least according to their website) and thus technically a teeny tiny bit to small for my 700x23 tires. But I admit: this is a lame excuse for my urge to build a new wheel. An additional boost to this urge actually came from a gift from my friend Löby, who gave me an old but functional dial indicator. The idea is to mount it to my truing stand, theoretically allowing me to true wheels down to 0.01mm. Well, I'm still working on the attachment to the stand which turns out to be a bit tricky.

But I've built up the wheel anyway. It's a 32 spoke Mavic Open Pro with DT Swiss Comp 2.0/1.8 spokes on an Shimano Ultegra HB-6600 front hub. After lacing the wheel the wrong way twice, three times was the charm and now it's all trued and tensioned. Figuring out the correct spoke tension was a little tricky because my Wheelsmith tensiometer's calibration table only gives values for their own double-butted spokes which are 2.0/1.7 and not 2.0/1.8. But since the absolute value for spoke tension is not that crucial anyway (Mavic recommends 1050-1100 N) it shouldn't matter too much.

One final note about the wheel: the Open Pros don't come with a wear indicator. Therefore I've measured the thickness of the rim's sidewall. A trick to do this: attach a little magnetic ball to your caliper in order to get around the flange of the rim. My measurements came to almost exactly 1.5mm. This should give me a good point of reference for judging rim wear.

Upgrade for Gunnar

Courtesy of the yearly sale of German online bike shop Rose, I've ordered a little upgrade for Gunnar. As you might remember, currently I have the old Alex DA-16/Deore wheel from my Cross-Check installed. The upgrade will be a Shimano 32H Ultegra Hub with DT Competition spokes on a Mavic Open Pro hub. That should shave a couple grams off of Gunnar's weight, look nicer, and be more appropriate for running thin tires. But first I have to wait for my Germany visit in order to pick up the components.

New dynamo front wheel

As a Christmas present for my accomplice, I wanted to build up a generator front wheel for her Fuji Touring. I bought the Shimano LX generator hub from Germany for a pretty good price and got a Mavic A319 front wheel and DT Swiss Champion 2.0 290 mm spokes from my LBS. Last night I finally built up the wheel and it went pretty well. It's definitely easier the second time, and my tensiometer helped a lot, too. Once I find a cheap Ultegra hub on ebay, I'll build a new front wheel for Gunnar...

Starting anew: chain, lights, front wheel

I had set up this blog a year ago or so, thinking I'd blog about my riding and other bike-related stuff. Well, obviously it didn't happen. So this is a new start, with a more limited goal: keep track of my maintenance, new acquisitions for my bike, kilometrage.

My total kilometrage count is somewhat off because I accidentally cut off the wire of my bike computer and it took me a while to get the spare part. But now all is good an running.

Latest maintenance:

• new chain (SRAM with PowerLock): 18 $ The old chain was getting to 0.75% elongation and I thought I'd better change early and do the switching technique to keep my cassette alive for longer. So I'll keep the old chain and put it back on once the current one has reached .75%.
  
• installed BUMM Toplight Line Plus rear light (about 30 $). This light just was introduced at the last Eurobike and so far it looks very good. There have been rumors about a recall of faulty lights but no definitive info on this yet. I'll be really pissed if I have to exchange them. The installation on my Jandd rear rack required some improvisation. The Toplight has two horizontal mounting bolts, spaced 50 mm, whereas the rack only has two vertical holes in the center. Solution: I cut a strip of metal out of a bean can and drilled three holes into it. I'm not sure how durable this solution is but for now it works great. I had checked the local Lowe's for appropriate pieces of metal but the metric spacing makes it difficult to find anything. Yeah DIY.
• truing and tensioning: A while ago I built up a new generator hub front wheel. Shimano DH3N-80, Mavic Open Pro 32 hole, DT Swiss 14 gauge spokes. Initially I didn't have truing stand and only used zip ties for truing. This worked more or less but I still got a truing stand and re-trued the wheels. This made them more true but I could clearly see that the spoke tension was rather uneven. Thus I decided to also invest in a Wheelsmith tensiometer (50 $ at LBS). Using the combo of truing stand and tensiometer was an interesting experience that taught me some things about proper wheel truing. Achieving both perfectly true wheels and even spoke tensions isn't possible but I think I've achieved a good compromise. I'll test the wheels again in 500 km or so and will see how they held up.