WheelBuilder Personal Edition

Current Release: Ver 1 21.0: 11/05/2012
Terms: Free for personal use
Requirements: OS X 10.4. or higher; Windows XP or higher: ~ 1min download
Technical Support: wheelbuilders@me.com

WheelBuilder PE by daLynchi is a database that incorporates a Spoke Length Calculator, post-build analyser and gear calculator. Why another spoke length calculator when there's plenty out there on the 'net, many of them with long and honourable histories? Well first of all I wanted something that did not rely on an internet connection (once you've downloaded the application that is). Secondly I wanted something that could record my wheel builds without having to register on a web site and where I can record anything I like, not just what the web site allows. And finally I wanted something self-contained, that is it doesn't require another programme such as Excel in order for it to function.

WheelBuilder PE

: Mac | Win

WheelBuilder PE is built upon a database so that each wheel you build can have its own record. It's also what is called a "run-time" which means that all the database functionality is built in so that you don't need any other software for it to run. This does lead to a larger file size than you might expect to download but it's still only a minute or so over a broadband connection. (Comparable to bundling say, Excel with a spreadsheet-based spoke length calculator). A single compressed file is provided for either Mac or Windows.

WheelBuilder PE is copyright but is provided free for personal use.

Spoke Length Calculator
  • Uses industry standard spoke length formula
  • No hidden assumptions
  • Can enter different lacing for each side of the wheel
  • Multiple crossings per side calculated automatically
  • Fractional crossing values can be entered for paired/triplet patterns
  • Incorporate and record compensations
Post Build Analysis
  • Record Radial, Lateral and dishing tolerances
  • Record individual spoke tensions
  • Calculates average spoke tensions per side
  • Visual alerts when tolerances and tensions are outside 'spec
Gear Calculator
  • Work in Gear Inches, Feet per rev, Metres per rev, MPH, KPH
  • Side by side "what if" comparison of gear combinations
  • Calculates front and rear capacities
  • Calculates max and min chain lengths
  • Record each wheel built
  • Large free-form notes field
  • Powerful search functions
  • Macintosh & Windows versions
  • Duplicate previous builds
  • Inbuilt help and examples

Installation is simple and very much the same for both Mac and PC. Once you have downloaded and decompressed the software for your platform, simply drag the resulting folder to any convenient place on your disk. WheelBuilder PE is a self-contained application that requires no additional software to run. This does mean that the download is around 30Mb as not only is it a database, but the engine to run that database is embedded in the solution too. Even so the download shouldn't take more than a couple of minutes over broadband.

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Double-click the folder icon - the one with the little black arrow on it to launch WBPE. (The Windows folder displays many more files but the one to launch is still the one with the folder icon.)

Download: Mac | Win

Post-build Analysis

Many wheel builders produce true and reliable wheels simply through experience and feel they have no need for the amount of detailed recording offered here. That’s fine and I would not argue with them about it. But it’s equally true that if you build a wheel for someone else, then as soon as you hand it over, you have no control over the kind of treatment it will receive. How do you subsequently prove, should a dispute arise, that the wheel was fit for purpose when new? You can only do so if you record its radial, lateral and dishing dimensions and the final spoke tensions. Tedious though this may seem, with practice it only adds a few minutes to the overall build. Of course, you will also need to use deflection gauges and a tensiometer.

Comments welcome:

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Download: Mac | Win

Gear Calculator
Well, since we are interested in wheels I thought this would be handy. Gear Inches, Development and Speed in both imperial and metric units with drive train capacities and chain length calculation.

Once again there are plenty of gear calculators available already so why do another one? Firstly for convenience - it's built right in to where you record your wheels. But secondly I figured two is better than one. Mostly what you want to do when thinking about gearing is to compare one set up with another. So the calculator here is actually two calculators side by side so you can do just that.

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Download: Mac | Win

Measuring Components

Wheel building newsgroups are littered with threads asking for databases of hub and rim dimensions for spoke length calculation. Whilst a database of components seems like a simple thing to do at first, it doesn't take long to realise how difficult such it is to maintain. Just scraping initial information from different manufacturer's published spec's is tedious enough but keeping up to date with their new products is near impossible.

Experienced wheel builders don't rely completely on published specs anyway so why not learn how to measure the components yourself? It's not difficult and I have provided what I hope are plenty of descriptions in the help files.


Pitch Circle Diameter (PCD)
The PCD is the diameter of the circle that passes through the centre of the spoke holes. It may be different for left and right flanges. It is usually between 38mm and 67mm and is a critical measurement so make several measurements and average the results.

Spoke Hole Diameter (SHD or ø)
SHD is the diameter of each spoke hole.

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Over Lock Dimension (OLD)
OLD is the distance between the outside flats of the lock nuts and corresponds to the frame gaps front and rear. Note that the axle itself protrudes some way beyond the OLD so as to engage with the drop outs. Half the OLD equates to the centre line of the hub.

Centre to Left Flange and Centre to Right Flange
Clf and Clr are the two other important measurements. They are not measured directly as it's impossible to judge the centre line of the hub by eye.

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Instead the dimensions x and y are measured and subtracted from half the OLD to provide C and D respectively. The measurements can be made by removing the Quick Release if attached and dropping each side of the hub into a hole in a flat surface just big enough for the axle width. The distance from the flat surface to the flange can then be taken with a ruler. Holding the flat face of the over lock nut against a good straight edge of a desk or table can also be useful.

Note that spoke lengths need to be calculated for EACH flange on each hub front and rear. Front non-disc hubs will probably have equal length spokes on both left and right flanges. Rear hubs that carry the drive mechanism such as a cassette will have different length spokes on the left flange (the "non-drive" side) to the length of spokes on the right side (the "drive" side).

WheelBuilder PE's spoke length formula requires a measurement for the "Effective Rim Diameter" or ERD, the original definition of which is the distance across the tops of opposite nipple heads. As this dimension is by far the longest of the triangle formed by spoke, hub and rim it is the measurement that has the most influence on the final spoke length.

Unfortunately not all manufacturers use the above definition for ERD. Some use the Nipple Seat Diameter (NSD) which is shorter than the ERD by twice the hight of the nipple head. Do not use this with WheelBuilder PE, it's formula requires the ERD.

An easy way to measure ERD is to first take the distance across opposite nipples measured from tail end to tail end and then add twice the length of the nipple. If you have a couple of spokes handy, put them through opposite spoke holes in the rim and thread nipples on to them. Slip a small elastic band around the "J" bends of the spokes to hold them in place whilst you measure across the nipple ends. Do this several times around the wheel and average the results.

This is such a simple measurement to take that it makes no sense at all to rely on anyone else's measurement - not even the manufacturer's. Do it yourself and believe your own eyes!


It's a work in progress but I have WheelBuilder PE a video of how to measure your hub and rim. I haven't yet optimised it for download so it's a still a 13Mb QT file at the moment.

Download: QT | Win

WBPE Manual

Download : PDF

Coming Up
The observant will notice a couple of unused buttons. There's other tools I'd like to implement so watch this space!

Donations very gratefully received.