Quoting a wheel review from somewhere else on this site, "Wheels are pretty much round and as long as they turn around on the axles, life is pretty much ok right?"
That's pretty much the way many of us feel about wheels. We take their roundness and rollingness pretty much granted, but then there are guys like Dan who obsesses over wheels and rolling weights and rotating mass and spoke patterns, materials, finish and all the stuff that adds cost to wheel sets. Why? That was my simple question. I mean it is easy to see that if the wheels actually weigh less, that the bike will weigh less and we will climb hills better right?
I decided to get some wheels built and see what the fuss is all about and so I contacted Dave Fike of Back Bay Bicycles in Boston Mass to ask him if he wanted to play. We decided to build a set of wheels for my Cannondale SIX13. Dave was happy to supply his expert services.
Dave, a licensed Race Mechanic, learned his wheel building skills at a young age under the watchful eye of Paul Vittorio Rosatto the owner of The A. A. Vittorio Cycles, famous for high end racing gear. Dave describes his experience with Paul as follows. "Paul Vittorio Rosatto took me in when I was 14 and started passing on what he had learned over the years about building. He's built 2700 sets of wheels over 30 years and he's definitely somebody I would consider a master wheel builder. He was known all over the race circuit. He was the "go to guy" for a set of wheels. If you build a set of wheels that nobody else's will stand up to, you are way ahead and he was. It was one of the first things he took me aside to show me."
Dave then honed his skills with more years of race support on the Mavic Race team keeping their race wheels round and straight. He literally has built and repaired literally thousands of wheels.
Our discussion and planning started with the questions and considerations Dave brings to the decision about what wheels to build and how. Rider size and power are the first considerations, then the terrain and riding style. The ideal wheel is not over built, but rather built to withstand the normal useage under a specific rider. In my case, I weigh in at around 180 and have medium to strong pedal torque, so Dave decided upon a set of steel DT Swiss components all around.
Gary: I see you are using DT Swiss Hubs, tell us about those, Why?
Dave: The features are light weight and durability. It's the perfect fit for someone who wants a light weight wheel, yet wants it to last a life time. You're looking at 96 grams for the front hub and 240 grams for the rear. We're building them using DT Swiss Rims, they're just a nice stable platform to use. The hub is made by a spoke company so they tend to put a bit more attention into how the hub is manufactured with regard to making it easier to accommodate the person who is building the wheels. The canted flanges, the way that the holes are shelved and drilled out in the middle make it easier to seat the heads. DT just does a nicer job overall in how they put the set together.
The next question to come up was about spoke lacing and what advantages and disadvantages each style of wheel lacing held. As it turned out, there really wasn't a whole lot of performance differences except for the degree of difficulty in the build. The one exception being what is called radial lacing, where each spoke goes straight out to the rim without crossing any other spokes. Generally, Dave seemed less than impressed with radial lacing.
Gary: I see you are starting to lace these wheels together, do you have a particular pattern in mind, as to whether they are cross or radial? What are the descriptive names that tell you the different patterns?
::Editor's Note: "1 cross" refers to a spoke pattern in which a single spoke crosses only one other spoke in the wheel on its way from the hub to the rim. 2 crosses twice, and 3 cross crosses three spokes::
Dave: It starts out with the radial lacing which is not strong. There are some benefits to it I guess. Some people build a one cross, which doesn't have all that much more strength to it. Then two cross, which is popular for the rear wheels to go to the lighter end of things.
You usually run two cross on the non-drive side and three cross on the drive side. The two cross pattern allows you to use a shorter spoke, a little bit lighter weight. The non drive side is not really taking up a lot of force so you don't have to worry about that aspect of it. Then you have three cross which is one of the strongest ways to build a wheel which is what we are doing here today. Its my personal favorite. Its one of the easier ones to work with, but it also tends to last the longest and tends to have the most strength for the wheel itself.
There's also a whole slew of what I would guess you'd call perverse wheel building methods. There's one where you make the spokes one cross but then you twist the spokes together repetitively. The spokes come out, cross and twist and then you send them out in the opposite way. Its a really hard wheel to build, it makes for a really funky ride. There's always funky ways to build wheels, but spoke length calculation on a wheel like that is pretty much trial and error.
Gary: Can you put almost any spoke pattern in any given wheel set or hub?
Dave: No some hubs tell you straight out, if you lace this radially, due to the way the forces are applied, you will sheer the flange off the hub. Some manufactures like DT Swiss that we are using here, make a special front hub to use if you are planning on lacing the wheel radially. It's reinforced to the point where is weighs some 30 grams heavier because the flanges are twice the size. Another couple of differences are that you can use bladed spokes. But you need special hubs for that which have a different hole. The hub itself will also be set up differently in order to accommodate a bladed spoke.
Gary: I see that you have three or four different piles of spoke what's that all about?
Dave: It just keeps them separated. You lace a wheel in four stages. You start with one side, going every other hole with the inbound spokes You start with the wheel on a flat plane looking at the valve hole. Some rims have offset spoke holes, some to the left, some to the right, these do not but if they did the first hole after the valve hole would be laced going up first. Then you would lace every fourth hole on the same side. The you flip it over and do the same thing inbound starting with the spoke hole off to the side of it so that you get a pair of spokes going in the same direction. After you get the first fourteen, the hub is kind of bowed out and the spokes are all funky. You have to give the hub a twist inside of the rim to set the angle on the spokes. Then you go back to the original side, and you do the other seven from the inside going out and that's where you get your lacing pattern and the overall strength of the wheel starts to take form.
Gary: Now are all of these spokes the same length and gauge, or are they different depending upon where they are going in the wheel?
Dave: This is a front wheel and we are lacing three cross so they are all the same size and gauge, 2.0 / 1.8 double butted. The blue stuff you see on the spoke thread is actually a treatment called Spoke Prep by Wheelsmith. It is a lubricant first, making it easier to build the wheel. But then it acts as a locking compound once the torque is put on it. As you ride, if you hit something like a pot hole the rim flex allows the tension to come off of the spoke and nipple. That can be enough for the nipple to loosen up. If the nipple backs off as little as an eight of a turn it can be enough for your wheel to go our of true and make your brakes rub your rim.
Dan: Is there any wheel where you might use multiple gauges?
Dave: Yes. This rear wheel which I built yesterday has a straight 14 gauge on the drive side 290 mm in length, three cross. The non-drive side, two cross, 2.0 / 1.8 double butted which is 14-15 gauge, 291 mm because of the overall dishing of the wheel.
This is where the rear wheels get tricky. On the front wheel all the spokes are the same length, the hubs are directly centered, and everything is the same tension. On a rear wheel, the drive side is under more tension, and it has shorter spokes. The non drive side is lighter tension, longer spokes and you have to get everything to come up evenly which gets a little tricky. Doing a front wheel, is relatively easy because you just bring it up step by step together.
But a rear wheel can tend to put you through the ringer sometimes. Lets say you have somebody that wants two cross on the non-drive, three cross on the drive. Doing the rim twist - when you twist the hub into the rim, you have to be really careful about it, working in stages. You have to figure your spoke length differences, since the hub will twist the same amount, but the way that the spokes end up on one side (the angle relative to the radius of the wheel) winds up being different. ::Editor's Note: Dave indicates spoke sets on opposite sides of the wheel:: It's still a wheel that gives me a run for my money when I attempt to build one.
Gary: Ok so somebody calls up and says, "Gee Dave, I saw this great article in Pedal Pushers Online about your custom wheel sets and I want you to build me a set." How would the interview go?
Dave: It would start with talking about their riding experiences, how they ride. The more I know about how you ride, the more I know about how the wheel needs to be built. Rider weight, rider style, riding conditions, if somebody lives in Kansas and all they do is ride country roads that are well maintained, you can definitely go with a lighter rim and spokes than somebody that lives in Manhattan and needs to get through the city all the time.
Gary: To the person who doesn't understand, they look at the spokes and they say, "Hey, it's steel wire, what's the big deal?"
Dave: It's not that some spokes are so much better than others, it's more a matter of personal preference. The reason to go with a steel spoke over an aluminum one is anybody that's ridden an old steel bike, or a new steel bike, over an aluminum bike, aluminum transmits all the shock and vibration directly to you. Nice and stiff, nice and light, nice and quick, but it's uncomfortable as all hell. If you look at the classic races, all the guys that get paid the big bucks run the ultra light wheels, with the carbon rims and everything during the races. The rest of the season you'll see them running 36 spoked steel spoke wheels that were built by their mechanics or by their sponsors, because that is the strongest wheel possible.
At this point the wheel has been brought up to some tension and Dave has placed the wheel into the truing stand...
Dave: ::As the wheel spins slowly with a better than reasonable degree of true:: Oh God I love doing front wheels...
Gary: Is it an illusion or does the wheel have a little hop in it?
Dave: Uh huh, that happens as you bring up the tension in it. We work that out as we go along.
Dan: Now what's the story with steel spokes, is there any kind of break in period where they are stretching?
Dave: That depends upon how the wheel is built. Sometimes what is happening is that the spoke is beginning to seat itself more into the flange and that will increase the length and decrease the tension. That's actually one of the things that we take care of right now. We seat the spoke nipples now. We don't give it the opportunity to take too long for them to seat themselves. We center punch the head of the spoke into the hub so that there is no place for it to go.
Dan: When you're done with this now, these wheels will be good for a long time without any truing or anything?
Dave: You could always end up needing truing. Chances are you won't, but you can always hit something that could totally screw 'em up. You will however definitely have a lot less maintenance than usual. Also if you ever look at a production bicycle wheel, When they build a wheel by machine, the machine shoots spoke in in only one direction and with a single overlaying pattern regardless of the side or direction of the spoke travel. When a wheel is built by hand the overlaying of the spokes is mirrored and balanced, so the forces of the wheel as it travels are balanced from rim to hub. A machine laced wheel, even through the tensions are balanced, the nature of the machine lacing does not allow fully balanced road to hub force vectors on both sides of the wheel. Which is where some of the problems tend to come in.
Gary: So the machine built wheel is built from only one side basically. Where as the hand built wheel is built symmetrically from both sides?
Dave: Right it shoots them... the pushing spokes, instead of both spokes going inbound, one side is inbound, and the other side is outbound, and the pulling spokes instead of being outbound, one side os outbound and the other side is inbound. On the hand built wheel on both sides of the wheel the pulling spokes are outbound and the pushing spokes are inbound.
What we are doing now is lubricating the surface between the head of the spoke nipple and the eyelet of the rim, because once the tension comes up, there can be enough friction to where it can lock the nipple up and you can shear the sides off of it and you have to start all over again. So with this it relieves the friction between the sides of the nipple and the rim itself. Its time for the last step.
Gary: Now if you get your trueness shouldn't the roundness be there too?
Dave: No, Trueness is on a horizontal plane, roundness is on a vertical plane. You can have a wheel that's true...
Gary: but still have a hop in it?
Dave: Yeah, this one has a very little one. It's almost a guarantee that it's going to... that's where it becomes a balance of the two.
Dan: So how do you take a hop out of a wheel?
Dave: When you have a wheel that is out of true, you tighten a spoke opposite the bend, and you pull it back toward the center, with a hop you tighten both sides in the same spot and that pulls the hop in. It's through steps like this that I believe until there is true AI that you can't have a machine build a wheel.
Gary: Now do you have a certain feel that you are going for on that spoke wrench, in terms of how tight you want that spoke to be, or are you just tightening them randomly?
Dave: For now I am doing it in small increments just to get the wheel straight. You start to feel it in the spoke nipple if some spokes are coming under too much tension, and then you kind of back track and work it back the opposite way. Because if in building a wheel you make all your adjustments by tightening the spokes, sooner or later the spokes become too tight. You can make the same adjustments by loosening the spokes. You just loosen the opposite spoke from the one you would have tightened.
Gary: Now in theory in a perfect world a true wheel without any hops in it should have the same tension on all the spokes, shouldn't it?
Dave: Yes relatively.
Gary: Do you find that that is in fact true? Like for instance, we have this spoke tension meter, if we were to measure the spoke tension after we built this new wheel, would the spoke tension be equal?
Dave: For the most part, sometimes it is not true. If there was a defect in the rim, I have built wheels where to get them straight and true, there was not even spoke tension, but I never had any problem with the the wheel in terms of integrity or anything. It was just something that I ran into while building it. A Lot of times I won;t even use the tensometer on a front wheel, because they are all going to be the same. You can do it by feel. One of the things we look for is every couple of stages you do a stress release of the spokes. (By stretching them in a fashion like playing a harp) you can actually hear them pop.
Dan: Its kind of like guitar tuning, after you make an adjustment you give 'em a stretch So that it pulls any kind of snag?
Dave: Yeah cause what is happening is you get spoke twist. You turn the spoke nipple and the spoke twists, instead of threading up the nipple, and you didn't actually do anything to tighten the spoke. As soon as you relieve it you kind of go back. By doing the stress relief every now and then, you kind of pop things free. That's why we use the spoke prep and the tri-flow, after you do a spoke release, tension release, you kind of go back and you play with the crossed ones. What you're going for is the overall feel, like those two are tight... those are loose...
::At this point Dave is running the wheel through the truing stand and making slight adjustments... The sound of the rim scraping the points of the stand is the only sound::
Gary: Can you believe this guy scratching up my rims like that.... ::Laughter::
Dave: The tire covers that... ::Laughter::
Dan: You can ask for money off...
Dave: Now on the gauge itself (the truing stand) there is always a little bit of apparent rise and fall based upon the side wall if the rim, but if you come over here, and look at it from this direction, you can see that the rim surface itself is perfectly round. We're not getting any actual hop (well a very slight hop) but on the visual comparison of the side wall it appears to have a substantial hop. It all depends upon the machining of the side wall, and particularly if they anodize the side wall as they have in this case, it makes it look even larger when in fact the wheel is straight. You have to be able to discern the difference between not perfect machining on the outside and the actual roundness of the wheel. Another element that give the impression of out of round, are tires particularly colored tires. The bead is never perfect and as the wheel spins, the tires make it appear that the wheel is all wobbly, when if fact it is perfectly true and round, and it is merely the pattern of color on the tire that is slightly off.
Well this is about as straight as it gets...
Gary: ::Laughing:: Its a beautiful thing.
Dave: now there is one other measurement that you have to worry about and that is called dishing, making certain that the hub is perfectly centered in the wheel side to side. Now there are two ways to measure it. One is to use the dishing tool, which I left on the counter at the shop, the other is how we do it when we have to true a wheel on the road.
(at this point Dave mounts the wheel in the fork)
Dave: Dead Center
Gary: What are we looking at? the brake or the fork?
Dave: Nope the fork! The dishing of the wheel gets it to ride dead center. With some bike companies, the forks are never perfect. So even if the wheel is dished perfectly, if the drop outs are not perfect, it can be off to one side or the other. So, I like to put it on the gauge, but I also like to put it on the bike that it is being built for. Now you look at a couple of things, the distance between the rim and this leg and the rim and the opposite leg and the overall centering of the rim in the fork. This is why I like front wheel, because if it is built right, 99% of the time it is also properly dished because you don't have the multiple spoke lengths.
Feel the weight on that. ::Ohhs and Ahhs::
Gary: (As he spins the wheel holding the axle) Can you believe this? There is no vibration or mechanical feel to this, it spins completely without any apparent friction. Good bearings are a huge difference!
Dan: Same with pedals, I have mentioned the difference that the bearing make in pedal smoothness and perceived effort.
Dan: So Gary are you gonna put some tires on these wheels? Maybe something with 200,000 miles on them?
Gary: Yeah you got some with like gouges and slits in 'em and with the threads showing? (Discussion of Michelin Axial Carbons)