How to Choose Spokes For a Bicycle Wheel
Spoke Lengths Made Easy
There seems to be a lot of confusion surrounding selecting the correct spoke length for building a bicycle wheel.
Selecting a spoke length needn't be difficult or confusing at all. There are several methods of arriving at the correct spoke length. All you really need is some simple information to help you to choose the correct length every time.
All the information that you need is contained in this article.
Measuring a Spoke
.. and the easiest method of selecting the correct spoke length
A spoke should be measured from inside the bend to the very end of the spoke including the thread.
If you're rebuilding an existing wheel and you aren't changing the spoking pattern you can select the correct spoke length by removing one of the existing spokes and measuring it.
If you need to cut the spokes out you will need to cut just one spoke initially so you can measure the two halves. Once you have cut more than one spoke it might not be possible to decide which parts are from the same spoke.
This is the easiest way to determine spoke length and I always use this method whenever possible.
Building Your Data
Recording what you have built
As you build wheels you will find that you get to know which spokes to use because you have built something similar before. Whenever you build a wheel write down all of the details of that wheel for future use.
You will need to make a note of:
Exact model and size of rim
Exact model of hub
Spoking pattern (3 cross, 4 cross)
Number of spokes
Front or rear
and don't forget to add the length of spoke you used. :-)
If you are good with computers you could record the information in a database or spreadsheet. Alternatively you could record it in a notebook.
Use Your Existing Knowledge And Experience
If you don't have any previous knowledge still read this section
If you build wheels regularly you will get a feel for which length you will need for at least the most common rim and hub combinations.
Two of the most common combinations are:
700c on small flange hub = 295mm
26 x 1.75 (ATB) on small flange hub = 263mm
These measurement are based on a 36 spoke wheel built 3-cross and are approximate but will give you a good start. A rim with a deeper section than standard will take a slightly shorter spoke.
As you build your experience these combinations, and others, will become second nature as will the amount to shorten or lengthen your choice based on variations from normal.
Best Kept Secret Exposed!
Spoke length is not critical. It is possible to be 2mm either side of the theoretically correct length and still build an excellent wheel.
My Methods for Selecting Spokes - These are the methods I use in my workshop
- Measuring a spoke from an existing wheel.
- Selecting a spoke length from my existing data of previous builds
- Estimate the spoke length from my personal experience of wheel-building. Try it and reselect the correct length if necessary.
- Use a spoke calculator program
Use a Spoke Length Calculator
There are times when a wheel is so different from the usual builds that it is very difficult to decide what spoke length to use. Years ago we used to start with our best estimate then experiment until we found the correct length.
These days computers make life a lot easier. There are several spoke length calculators available online. Some are not all that good, but there is one calculator that is simple to use and produces correct results every time. This is the calculator that I use:
- Wheelpro Spoke Length Calculator
Roger Musson who owns Wheelpro and designed this calculator is one of my competitors. Although I have never met Roger nor seen or handled any of his finished work I can be confident from what he offers and the passion that he has for the subject that