Spoke length calculator review
The new spoke length calculator is now part of the wheelbuilding book, and the calculator resides on a new website (as shown in the book).
It will calculate spoke lengths for:
- Normal wheels
- Straightpull hubs
- Paired hole hubs
- Triplet lacing (J bend and straightpull)
- Campagnolo G3 lacing (J bend and straightpull)
- Eccentric (clown wheels), including multiple cross lacing - per side!
- Paired spoke lacing
- Mismatched hubs and rims (for example 36 hole hub and a 32 hole rim, 32 hole hub and a 24 hole rim)
The calculator uses elongation equations to determine more accurate spoke lengths, which is important if you are using stretchy thin spokes such as Sapim Laser, Sapim CX-Ray, DT Revolution, all of which can stretch under tension by almost 1mm.
There's a lot of expert knowledge built in to the calculator to trap bad entries and give advice. Plus lots of other useful features and print formats that will be appreciated by wheelbuilders. Remember, this calculator was created over many years to suit the requirements of my own wheelbuilding business and if I needed a particular feature, I just added it.
The calculator also draws a scale diagram of the wheel and then allows you to explore the wheel in detail using display options and geometry guidelines. The diagram is also used to show you how to lace the more complex patterns such as triplet lacing and for lacing patterns where there are multiple spoke lengths per side.
The diagram is also used to study wheel geometry, and if you like Math and Geometry then the calculator will keep you occupied for days! A note to mathematician wheelbuilders - it's all coded in vector algebra.
The wheelbuilding book and calculator work together referencing each other.
It's in continual development. Here are the latest changes.
If there is enough support...
I plan to make a version of the calculator available for you to use on your local computer, which will ensure you will always be able to work out the length of your spokes long after this website and myself are gone! If you want to support this project your help is most appreciated. Just buy a book! It's actually very good (and doesn't cost much).
Other spoke length calculators
Since my background is mechanical engineering, maths and computing, and also a long time wheelbuilder and a long time creator of spoke length calculators, I've looked in detail at all the other online calculators and studied their source code. They all use the basic spoke length formula which limits them in what they can do. Which means they all have low functionality, many have errors, bad user interfaces and they are all very old and unlikely to ever get updated.
I'm not saying this to promote the calculator I created, I'm just giving you my personal opinion.