HOW TO:MIKE HOPKINS SHIMANO WHEEL BUILD

Years ago, when mountain bikes had rim brakes, I used to have trouble with factory wheels taking on the shape of a taco or popping spokes or just plain going out of true all the time. It was in that time that my brother introduced me to a book, "The Bicycle Wheel", by an engineer named Jobst Brandt. The book discussed the physics behind the bicycle wheel, and then described a wheel building process to use in order to build the strongest wheel possible. I have followed his recommendations ever since, with great success.

With the advent of disc brakes and the improvement of factory wheels, the wheel builder is less busy today than he used to be, but the torque of the disc brake rotor and the abuse that the younger riders are putting on  wheels, still requires the methods learned in "The Bicycle Wheel". I have been building wheels for Mike Hopkins for a couple of years now and I thought it would be good to document the process for the world to see, so here goes.

The component selection is most important. The construction of a strong wheel that will withstand the forces applied to it in a competition like the Red Bull Rampage, requires the best of materials and build processes. Mike uses Shimano Saint hubs and rims and DT Swiss Double butted 2.0-1.8 spokes. These are great choices. The double butted spokes are one of the key things in the whole build because they provide the ability to pre-stress (stretch the spoke ) the supporting spoke columns so that when heavily weighted the spoke remains under tension and the spoke nipple does not float. If the nipple floats then it will start to come undone and the result will be an out of balance(tension) wheel that will go out of true and lose its strength.

Components choosen, let's get to the build.

1. Measure spoke nipple to spoke nipple diameter of rim.

2. Measure the dimensions of the hub, these include hub width(2 hub widths required because of different offsets on disc and non disc sides), flange hole spacing, flange hole size, and overall hub width. Make sure the number of holes in the hub matches the number of holes in the rim. I have always used 32 hole rims myself but there are a growing number of different configurations possible.The diagram below shows the required measurements. Decide on the lacing pattern. I always build a 3 cross wheel because Jobst Brandt(The Bicycle Wheel) concluded that it was the strongest configuration for the most general use.

This is from the ProWheelBuilder.com site. Useful site for some hub dimensions.

3. Feed this data into a spoke length calculator. There are many available on the internet but I use my own spreadsheet(I did the math) because my results have turned out to be more accurate over the years.

4. Gather 16 (assuming 32 hole hub and rim)of each spoke length. Typically the disc side will have a different length(up to 2mm different) than the non-disc side but this varies from hub to hub. Dip the threads in motor oil or a good lubricant because I will be turning these to a fairly high tension and I want them to turn easily.

5. Lube the spoke eyelets in the rim with grease, for the same reason that you oiled the threads on the spokes.

6. Now I am ready to start to lace the wheel. I always feel like I am knitting when I do this, knit one perl two, yeah I learned to knit a little from my mom. The first spokes to go on are the critical ones, get these wrong and the whole thing can end up just plain wrong. These spokes are the puller spokes as I call them, and they thread from the outside in and must line up with the offset in the rim spoke holes(yes they are slightly offset to each side). I usually set these up so that the disc pulls on these when braking and the spokes will not interfere with the air valve of the wheel.

7.Time for the cross over spokes. Three cross means that these cross over spokes will pass over two other spokes and under a third before being secured to the rim. This takes hand strength and mom's knitting instuctions to get the right result. The hand strength is required in order to bend each of these spokes at the elbow so that the contact between the spoke and the hub flange is as large as possible.

8. Make the wheel round by doing up each of the spokes the exact same amount, not tight but to the same spot, each of them. If my spoke lengths are good then I should be able to use the threads on the spoke as an indicator. Do up the nipple until the last thread is just covered.

9. Take the spokes up to tension by turning each nipple a set amount. Don't get in a hurry because you will wreck the roundness of the wheel. I start at the valve hole all the time and turn each nipple 1 turn, then around again using half a turn, then a quarter turn after that until the tensions start to rise. I keep going until my tension gauge starts to read close to my desire tension.

10. Relieve the stress on all spokes at the hub. I tap the spoke elbows with a hammer, which seems quite extreme, but I must get the spoke to contact the hub as much as possible. This ensures that the spokes will not lose as much tension as the wheel is ridden for the first 5-10 times. This process is worth doing to your factory wheels along with a tension balance in order to have a long lasting stable and true wheel.

11. Tension balance the wheel. I have not paid any attention to the trueness of the wheel from left to right just the roundness to this point. No use worrying about left right true, because I am not sure that all the spokes have equal tensions and are doing their part. At this point I use my tension guage(mine is a Wheelsmith but there are others) to make sure that all the spokes are sharing the load. Unfortunately the tension on one side are often different than the tension on the other side, due to different hub offsets and the angles these creat. It would be nice if the hubs set up a symmetric wheel, but if you remember your physics and your trigonometry we should be able to get everything to add up to zero. The forces in all dimensions should balance and every spoke should be doing an equal share of the balancing. I have to do this globally because one spoke has an effect on all the others, so I mark the slackers with a little piece of duct tape(lower tension than the average) and then up the tension of these by a quarter turn, check and repeat until equal tensions have been achieved. Remember one side will probably be different than the other. For example the disc side on a front wheel will typically be higher than the non-disc side due to the offset required to make room for the disc. I repeat this step until I get the required balance.

Using tension gauge.

Duct tape marking slackers.

12. Eliminate wind up. As the tensions get higher the spokes will turn at the same time as the nipples. In order to eliminate this I always go an eighth of a turn more then back up and I use an old pair of ski gloves to grab spoke pairs on either side and squeeze allowing the nipples to float slightly and unwind if necessary. Good hand strengthening exercise.

13. True the wheel. Now I pay attention to the left right and through a series of tension checks and loosen tighten steps get the wheel to run true and be in the middle of the wheel stand(this id call setting the dish), then repeat steps 11 and 12. A poorly dished wheel will cause the bike to track poorly and handling will be compromised.

14. Repeat 11 thru 13 as many times as it takes to get a balanced true wheel.

15. Final tension. I now take the wheel up to its final high tension. I usually go to 90 on my gauge for the highest tension spokes and the others just follow. Jobst Brandt said the higher the better. Watch it because the rim will distort if you go too high.

Mike's wheel set resting against the cooler. Time to open that cooler.

So there you go, a set of super balance Shimano Saint wheels with DT Swiss spokes destined for Mike Hopkin's Knolly Podium. If I can get him to bring them back for a quick retension after a weekend of riding at Silver Star Bike Park they will be even more bomber for the rides to come.