Words by: Max Morgan
A common question we receive all of the time is, 'What spoke length do I need?" If you are someone interested in building your own custom set of wheels, we are here to walk you through the 5 steps to do just that. If you are eager to build up a set of mountain bike wheels with your favorite hubs from Industry Nine or DT Swiss, how do you know what length spokes to use? How do you find the most important rim dimensions? You can build up your wheels in a 1 cross, 2 cross, or 3 cross spoke lacing pattern, but which pattern should you use for your particular wheels? We are here to answer all of these questions and more, that way you can build up your dream wheelset!
When it comes time to piece together your wheelset, you will want to know what hubs and rims you will be using before you know the appropriate spoke lengths you will need. To start, we are going to dive in to the dimensions you will need to take from your hubs. Most all manufacturers will have engineering drawers available online so you can pull all of this important information.
Now that we have all of the dimensions necessary for both your front and rear hubs, let's figure out what dimensions we need from the rims themselves. Because rims come in all different sizes, shapes, and styles, wheel and rim manufacturers generally publish all of the most important dimensions for their rim design. If you are having trouble finding the your rim's ERD (Effective Rim Diameter) and spoke offset, don't hesitate to give us a call here at Worldwide Cyclery, and we can get you squared away!
Zipp 3ZERO Moto wheels feature a unique moto inspired single wall rim with a 0mm offset design
For the most part, there are four different lacing patterns primarily used in cycling. Each of the different lacing patterns, radial, 1-cross, 2-cross, and 3-cross, have their own pros and cons. In general, most wheel builders refer to a 3-cross pattern as the standard lacing pattern for mountain bike wheels. When it comes time to build up your own custom wheels and you can't decide which lacing pattern best suits your build, give us a call at the shop and ask for Liam. Liam is the head mechanic at our California location and is a wizard when it comes to building wheels. Keep in mind that different lacing patterns require different spoke lengths.
Now that you have all of the different hub flange diameters, hub center to flange measurements, the rim's ERD, the rim's spoke offset, and the spoke count, the best way to determine the spoke lengths needed for your wheels is to use a spoke calculator. We are big fans of the QBP spoke calculator in particular. It's simple, easy to follow, and gives you a breakdown for different lacing patterns. Plug in all of the correct dimensions and the spoke calculator will spit out the necessary spoke length for both the non drive side (left) and drive side (right). Because the dimensions on the front and rear hubs may be different, remember to fill out the spoke calculator for both the front and rear wheels.
Now that you know how you are going to lace your new wheels and what spoke lengths to use, it's time to choose which spokes and spoke nipples best fit your build. DT Swiss is without a doubt the industry leader for spokes for all different bikes. DT is your one stop shop for not only spokes, but they also offer four different spoke nipples dedicated for different applications. First it's important to understand the different types of spokes that are out there. Let's break down the difference between straight gauge spokes, single butted spokes, double butted spokes, aero bladed spokes, and straight pull spokes. In the illustration below, you can see an example of a double butted spoke.
So here we go. I am in the process of building up a set of wheels for my own Santa Cruz V10, and so I figured this would be a good opportunity to walk you through the process. I know that I will be using Industry Nine Classic hubs and Santa Cruz Reserve DH 29" rims. First thing we need to do is go and track down all of the necessary information mentioned above for this particular hub and rim combination. Keep in mind that every rim and hub combination is different.
The Fox 49 fork on this bike uses 110mm boost spacing. Find the right information for your particular fork
The Santa Cruz V10 we are looking at here uses 157mm rear hub spacing. Make sure you know the rear hub spacing on your bike
Here is a breakdown of all of the dimensions for each Santa Cruz Reserve rim offering pulled from Santa Cruz's website
Now that we have all of the appropriate information for our Industry Nine hubs and Santa Cruz Reserve DH 29 rims, we can starting plugging that information in to the QBP spoke length calculator we mentioned before. Looking at the front wheel first, the non drive side (NDS) flange measures 58mm and the drive side (DS) flange measures 45mm. The NDS center to flange measures 27mm and the DS center to flange is 42mm. The Santa Cruz Reserve DH 29 rims have a 594mm ERD and feature a 3mm asymmetrical offset. Because these wheels will be ridden on a downhill bike and are guaranteed to see plenty of abuse, I will be using a standard 3-cross lacing pattern. You can see highlighted in blue in the photo below that this hub and rim combination for the front wheel calls for a 288mm J-bend spoke on the non drive side (left side) and a 291mm J-bend spoke on the drive side (right side).
Now looking at the rear wheel, the non drive side (NDS) flange measures 58mm and the drive side (DS) flange measures 60mm. The NDS center to flange measures 41mm and the DS center to flange is 29mm. The Santa Cruz Reserve DH 29 rims have a 594mm ERD and feature a 3mm asymmetrical offset. I will of course use the same 3-cross pattern on the rear wheel as well. You can see highlighted in blue in the photo below that this hub and rim combination for the rear wheel calls for a 289mm J-bend spoke on the non drive side (left side) and a 288mm J-bend spoke on the drive side (right side).
Now that we know exactly what spoke lengths to buy, all we need to do is decide which spokes and nipples to use. Because this is a high end mountain bike wheelset, I have decided to use double butted spokes, the DT Swiss Competition Race spokes in particular. The Competition race spokes feature a 2.0 - 1.6 - 2.0 profile compared to the 2.0 - 1.8 - 2.0 on the standard DT Competition spokes. Because the carbon Santa Cruz rim is very stiff, having a lighter spoke will give the wheels a bit more compliance and better feel over trail terrain. For spoke nipples I have decided to go with the DT Swiss Squorx Pro Head spoke nipples in aluminum. I hope that walking through this process has helped you understand the process of building up your own custom wheels and deciding what spoke lengths you need for your build.
This article was written / authored by Max Morgan. Max has been a professional downhill mountain bike racer for the last 10 years, competing in the UCI World Cup downhill series and U.S. Pro GRT series. Having ridden all different kinds of bikes on trails all over the world, Max's experiences being out on the circuit give him a unique perspective on what makes for a quality cycling component. Max also has degrees in Mechanical Engineering and Physics, and so if you don't see out on the trail, chances are he is probably in the garage tinkering on the next project.