Building wheels can be an interesting undertaking, or a complete pain in the arse, depending on how you look at it.
Second Time Round
Previously we posted an article about wheel building, I wrote this after building the wheels for my bike, feeling pretty chuffed with myself and full of confidence I moved on to building Mayu’s wheels. But after half an hour or so I noticed that the spokes were getting really tight really quickly, and it was obvious that the spokes were too f%#king short! I couldn’t understand why, I thought I had been so careful to calculate the length right, especially as I couldn’t return the spokes I’d bought, a big down side to some internet retailers. Bummer!
The first time I calculated our spokes for this wheel build, I was in Malaysia, it was very hot and humid and I was struggling to find the right specification for our hubs that I didn’t have in front of me. However after a few hours of brain melting internet trawling, I came up with some numbers. Happy, I proceeded to order the spoke lengths we needed. But a few weeks down the line, we have hit two problems, both my fault of course! But rather than you making the same silly mistakes please learn from mine instead.
Getting it Right
Firstly I stupidly changed the spec of Mayu’s hubs, without really thinking about the spoke lengths I’d already ordered, this of course meant that the spokes were no longer the correct length, what an idiot. The second mistake was not reading the spec of the spokes, it didn’t help that I was using google translate for a Japanese site. The low price should have been an alarm bell when ordering, I thought the spokes were stainless steel, unfortunately they are zinc, which means they will rust with time. At first I didn’t mind using them on my wheels because its a rim brake wheel, that will need to be rebuilt after 20,000km or so but Mayu’s bike is using disc, so I’d like her wheels to last for decades as there will be no wear on the rim, however if the spokes are going to rust, this won’t work.
So due those two mistakes it was back to the mind melting task of looking up hub specifications and re calculating the spoke lengths. This time instead of using odd bits of scrap paper and writing random numbers in no particular order, I decided to get methodical. In this article I want to share that process of finding the correct hub specification so you can easily calculate spoke length, I also want to talk about the decisions we have made when buying the components for our new set of wheels.
There are five main components to building a wheel, because of the nature of cycling we do, this post will focus on building a set of wheels for loaded touring, but the same applies for all wheels. When shopping for components we are not worried about weight, primarily we are looking for reliability and strength, without spending a fortune. In our opinion the selection we’ve made is the best and cheapest type of touring wheels and retails around 150 USD for a set.
This is a really important factor to get right, especially for touring. We met someone in Tajikistan who had to see his friend end their trip because his wheels basically fell apart. Clearly he’d done no research, and was trying to ride heavy ladened, on bad terrain, with a set of lightweight road wheels, it’s never going to work. For my bike, I was looking for a rim brake, 650b (27.5) rim that was wide enough (minimum internal rim width of 25mm) to accept 60-65mm tires to give me a bit more cushion on single track and gravel roads. After a lot of searching, these were the only options I could find:
The Ryde rim is 225g heavier than the cliffhanger from Velocity, and although I don’t really need the extra strength the Ryde Andra was much cheaper, around one third of the cost. Unfortunately Ryde don’t have any distribution in Japan, whereas Velocity are well represented here, so I had to have the rims shipped from the UK. Ryde have a very good reputation and we had used their Spudnik rims from Turkey to Japan with no complaints, so I can only have good things to say about them.
For touring we want strong, long lasting and rust free spokes. The best option for us is stainless steel 14g straight gauge spokes, for price vs their strength and only 1g heavier than double butted per spoke. After finding out that not only were the spokes I’d ordered the wrong size for Mayu, they were also the wrong material. After calculating the right sizes we did a bit of searching on the internet for high quality stainless steel spokes and found a local Japanese company called Hoshi Spokes. We’d never heard this name before, but it turns out they have been manufacturing spokes since 1921! And the best part is they are only 33km from Mayu’s house in Osaka!
Amazon had the sizes we needed, for a very reasonable price, but just before we hit the button Mayu sent them an email about our cycling project around Japan, and asked if they would be interested in supporting us with a set of spokes. They answered straight away to say yes! And a few days later we jumped on our bikes and cycled to their factory to introduce ourselves.
Unfortunately I don’t have any photos from our factory tour, as they keep that under wraps, but all their spokes are made to order and they produce a number of very high quality products. Ranging from the basic zinc spokes to double butted, oval and aero stainless steel spokes. The whole operation had such a hand crafted quality about it, and the guys behind it seemed so genuine and friendly. I don’t think I’ll ever be this happy about ordering the wrong spokes again, without that mistake we might never have heard about hoshi spokes.
Most manufacturers are making the nipples out of brass, and the standard size is 12mm in length. Hoshi make all of their nipples in house and supplied us with the amount we needed.
Personally I find this a bit of a mind field, there are a lot hub manufactures out there. Not having any experience with a sealed bearing hub, and feeling pretty confident to service a cup and cone hub we have always used Shimano. After trying a few cheapies we have found that the LX Deore hubs to be brilliant, very well sealed which results in low maintenance. However for the purpose of testing I wanted to try out the XT Deore alongside the LX Deore for our trip around Japan. I’ve heard that because the XT has a larger aluminium axle this makes the bearings smaller and therefore weaker. However time and experience will be the best test.
An important last component to ensure the tubes don’t come into contact with the spokes, it’s also import to get the correct width tape for the rim.
Before the spoke length can be calculated we have to be completely certain on the following things:
How Many Spokes?
Because I want a heavy duty wheel, and I don’t care too much about weight I will use 36 spokes for each wheel. This is important when you are choosing your rim and hub, they must match the number of spokes you want to use or the spokes must match the amount of holes you have in existing rim or hub.
Elliot’s Wheels - 36 spokes
Mayu’s Wheels - 36 spokes
What Spoke Pattern?
The most common spoke pattern is a 3 cross spoke pattern, is easy to build and there is a lot of information online about lacing a 3 cross pattern. All the wheels I have built have been 3 cross, so no reason to change I guess.
Elliot’s Wheels - 3 cross
Mayu’s Wheels - 3 cross
Front - Shimano XT Deore HB-T780 36 holes
Rear - Shimano XT Deore FH-T780 36 holes
Front - Shimano LX Deore HB-T675 36 holes disc brake
Rear - Shimano LX Deore FH-T675 36 holes disc brake
Elliot’s rim - Ryde Andra 40 36 holes MSW (machined sidewall for rim brakes)
Mayu’s rim - Ryde Andra 40 36 holes MSW (Mayu doesn’t need the machined sidewall, but it was cheaper to buy the same rims directly from Ryde as they had a minimum order)
Now that we have confirmed the components we can calculate and order the correct spoke lengths. In my very methodical second attempt of calculating the spoke lengths, I first drew a simple line drawing of the hubs I was using. It makes life so much easier if the diagram accurately depicts the hubs you are using. Important factors such as labelling the drive side of the hub and indicating the centre line. The drive side of the bike is the side where the cassette and chain is on. If you stand behind a bike, wheels on the ground, with the bike facing forward, the cassette and chain will be on the right side. So the drive side of a hub is the right side of the hub. It’s import not get mixed up with this.
In the line drawing indicates the drive side in each diagram and I make sure the drive side is always on the right. When calculating the spoke length using a spoke calculator, the calculator will ask you to input information for the left side and the right side (drive side) of the wheel. Therefore it’s important to understand which side is which. As far as I am aware industry standard for the right side is the drive side of the hub, the same goes for the right and left pedals. If you are still unsure what I mean you can look at end of the spindle on your pedals, they will indicate L or R.
Shimano haven’t made it particularly easy to find the information we need to input into the spoke calculator. The site pages for certain hubs often have important numbers missing on the website, I almost made a mistake as the first hub I was calculating only indicated flange diameter (not a measurement needed for calculating spoke length) instead we are looking for PCD (pitch circle diameter). Later I found a pdf on their website giving all the correct information, you can view it here.
So the three measurements you need from a shimano’s pdf are the following:
This is the distance from the center of each flange
This tells you how much the flanges are offset from the center line, but shimano don’t indicate which way the offset is. For the most part the offset will be towards the left on a rear freehub with or without disc brake, and to the right on a front hub with disc brake.
PCD (Pitch Circle Diameter) L/R
This measurement can differ on the left and right side by a mm or more, this is why it is important to understand what is the left and the right side of the hub. If you have the hub the wrong way round your spoke lengths will be incorrect. But some hubs have the same PCD for the left and right side.
Flange Distance L/R
Shimano has given us the overall flange distance, the spoke calculator needs two measurements, the flange distance left of the center line, and the flange distance from the right of the center line. To get this divide the overall flange distance by two and then minus or plus the offset.
Elliot’s Rear Hub - Shimano XT Deore FH-T780 36 holes
Flange Distance: 57.4mm
PCD L/R: 44/45mm
We know on a rear hub the offset is towards the left so we plus 6.6mm on the left and minus 6.6mm on the right.
Overall Flange Distance is 57.4 ÷ 2 = 28.7
Flange Distance Left = 35.3mm (28.7 + 6.6)
Flange Distance Right = 22.1mm (28.7 - 6.6)
At this stage we have all the information we need to fill in the spoke calculator. I like to use the spoke calculator from DT swiss, but there are few options out there. However a word of warning, some of them are off by 1 or 2mm, and this is a lot when calculating a spoke length, if you are unsure, I recommend inputting the data into 3 or 4 different calculators to confirm the results are correct. But I feel that the calculator from DT swiss is accurate every time. Below I have explained each data field referencing the calculator from DT swiss, I’m sure most of data fields are obvious but I have explained them one by one, using my rear hub as a reference:
Put User defined if you are not using a rim from dt swiss
DIAMETER/ERD (Effective Rim Diameter): 560mm (based on ryde andra 40 27.5inch)
This information should be available on the rim manufacturers website
Not sure how important this is but I put it in anyway, if you don’t know the weight it’s not a big deal
Put User defined classic if you are using a standard hub and spokes that have a j bend in them, most hubs are classic. If you are using a dt swiss hub, just select the hub you are using and all the information will be input for you.
PITCH CIRCLE LEFT: 44mm
PITCH CIRCLE RIGHT: 45mm
FLANGE DISTANCE LEFT: 35.3mm
FLANGE DISTANCE RIGHT: 22.1mm
Ø-SPOKE HOLE: Nearly all standard hubs have a hole diameter of 2.6mm, but it’s often difficult to find that information online, if you have the hub in front of you it’s best to measure the hub’s hole diameter.
WEIGHT: I leave this out
SPOKES LEFT: 2.0DT champion
Choose spoke: There is no user defined so you have to choose an option, for our build we are using 2mm (14g), straight gauge spokes, this is the equivalent to the 2.0 DT champion. DT swiss have a wide variety of spokes, so it’s likely you are going to find the equivalent to the spoke you are using.
SPOKES RIGHT: 2.0DT champion
For some wheel builds, customers will want different spokes on the left and right, I don’t fully understand the reasons why, but I have a feeling it's to save weight and mainly used in competition.
NUMBER OF SPOKES: 36
NUMBER OF INTERSECTIONS LEFT: 3
NUMBER OF INTERSECTIONS RIGHT: 3
This is referencing the cross pattern, for my wheel I am using a 3 cross pattern.
NIPPLES TYPE LEFT: 12mm DT Pro Lock Standard Brass
NIPPLES TYPE RIGHT: 12mm DT Pro Lock Standard Brass
Again DT swiss have a lot of options here when it comes to nipples, I am using a standard 12mm brass nipple from Hoshi spokes. If you are unsure, have a look at some images to determine what nipples you are using.
Once all that data is input into the calculator you should get the following four numbers:
SPOKE LENGTH LEFT:
SPOKE LENGTH RIGHT: