Spoke length calculation
Settings
Field settings:
Spokes | Select list | |
Cross | Select list | Select list |
Spoke dia. | Select list | Select list |
Frame offset | Select list |
Version
Project support
Do you use the calculator and find it useful?
To help with the development and hosting of the calculator please consider buying a wheelbuilding book.
It doesn't cost much, and you get a detailed book on wheelbuilding which also covers spoke lengths and wheel geometry in more detail, plus you get free updates when a new book is released.
Thanks!
Help
To get the most out of this calculator you need to read this help page (all of it).
If you want to know how the calculator evolved, then take a look here.
Contact details
If you have purchased a wheelbuilding book and have a question, then please get in touch.
Getting started
Every heading in the data entry form and the spoke length table is "clickable" and shows detailed help text. The help text is closed by clicking the close link, or click the same heading again, or click a new heading which will close the previous. On a mobile device do not try to close the help text by using the mobile navigation back arrow, close the text as advised.
When you select a new wheel type, always click Type in the data entry form because it gives information on the selected wheel.
Additional settings can be found in the system menu Ξ
The calculator runs in a single page, so never use your browsers back button.
Do not use your browsers print function, always use print buttons within the calculator because they produce specially formatted prints.
For use with stainless steel spokes. It cannot be used for titanium spokes, or any other spoke material, because those materials have different elongation properties.
Important
This is a high accuracy calculator and requires you to measure the rim ERD yourself and to specify the correct spoke diameter. Please read the help text for these two inputs because the rounding method assumes you made the correct entries. Always round the spoke lengths up. There's more help on spoke rounding when you calculate a spoke table and click the heading "Spoke lengths".
Calculate
When you start the calculator with a blank data entry form it will automatically make the calculation once it has sufficient information. From then on it will calculate each time an individual data value is changed.
If it cannot automatically calculate, you'll see a red Recalculate button (which is also a warning that the displayed spoke lengths or wheel drawing does not match the data inputs).
The Log will show you what the calculator has done. Either a detailed breakdown of the calculation, or the reason why the calculation was not performed. You don't need to check the Log on each calculation, but it's there should you need it.
Note, the 2023 wheelbuilding book describes the old method of making a calculation, a recent calculator update has now made it fully automatic.
The output
There will be a spoke length table, and beneath that is a summary table of the information used in the calculation, it's the same data you entered in the data entry form, but presented in a clear simple view so that it's easy to scan and look for any errors you may have made.
Menu item : Info
Shows the calculation url. If you want the drawing to be included in the url so that it automatically shows when the url is loaded, view the drawing and select any required drawing options.
The additional information shown within the Info menu is for use in an external data file, see next...
Menu item : DB (data base)
You can create external data files containing information about hubs, rims and wheels. Click the + symbol on the right to add a data file. You can add as many files as you want, files can be removed by clicking the X at the bottom of the file. If you click DB again, the data files are hidden and can be recalled again with another click.
Please see the full description of data files here.
Draw
This will draw the wheel following a successful calculation.
For more information on wheel geometry, understanding lacing patterns and a detailed guide on using the wheel drawing option see Appendix 4 in the wheelbuilding book.
All drawings are looking on the right side of the wheel (drive side), and the wheel is positioned so that the rim valve hole (shown in red) is at the top centre.
You can have multiple menu options active at any time.
Left - Right
Select which side of the wheel to show. When you look at the left side, you are viewing it through the wheel from the right side.
When looking at a single side, the hub outline is removed and the hub changed to light grey to make it easier to identify where the spoke ends touch the circumference (which is actually the PCD of the hub).
Click left then right to quickly toggle between the two sides, and click whatever is highlighted to return to the full view.
Leading - Trailing
Shows either the leading or trailing spokes. Remember, you are looking on the right side of the wheel and in use on the bike it will rotate clockwise and move off to the right.
Click leading then trailing to quickly toggle between the two spoke orientations, and click whatever is highlighted to return to the full view.
Leading and trailing spokes may not show for a radial wheel, this is explained in Appendix 4 in the wheelbuilding book, sub heading Radial Lacing.
Left green
This will show the left side spokes in green.
Guides
This will show guidelines that radiate from the centre through equally spaced hub holes. When you view a single side, only the guides for that side are shown. Guides are useful for studying wheel geometry.
The drawing is wrong!
The drawing is correct, it's just that some things aren't obvious until you think logically about what you are looking at. Also, pay attention to which selections you have activated.
The wheel will always be scaled to fit the display area, so reducing the rim erd does not make the drawing smaller because it gets scaled up to fit.
RM's drawing tools.
Do not apply ANY rotations Do not rotate valve to top Spoke zeroNormal
A hub using J bend spokes.
The hub and rim have the same number of equally spaced holes.
Option : Paired hub holes
The hub spoke holes are grouped in pairs, but the rim must always have equally spaced spoke holes.
If the option is unchecked the hub is treated as non paired and any previously entered values are ignored.
Erd helper
This is not applicable to Normal wheels, but the Erd helper is activated on these wheels and some off centre measuring holes are shown. This is for you to see how the helper works, and for you to give it a go. There's more information when you read the Erd help text (where the Erd helper is found).
Straight pull hub
A hub using straight pull spokes.
The geometry of the hub will dictate the cross pattern. Click "Cross" in the data entry form for additional notes on straight pull cross patterns.
The spoke offset is important, do not guess this entry!
Triplet lacing
Also known as 2:1 lacing.
For a detailed description of triplet lacing and compatible hubs, see Triplet lacing in the Wheel design chapter of the book.
The rim must be centrally drilled with no left/right hole stagger or a rim with a triplet specific spoke hole stagger.
For a given cross pattern there are two ways of lacing the side with the larger spoke count. Click "Lace option" in the data form for additional notes on theses lacing patterns.
Rim Erd measurement
If the wheel has an odd number of spokes, then the measuring holes will not be directly across the rim diameter. There are two ways of obtaining the erd:
- Use a small washer under one of the measuring spokes, and measure from the rim valve hole to the exact opposite spoke hole. Depending on the thickness of the washer and how the nipple sits in it, there may be a tiny difference to the true erd, but the effect on the spoke lengths will be negligible.
- Use the Erd helper. View the Erd help text and follow the instructions.
Or do both, and compare the results.
Front and Rear
For a front wheel, the "2" side is on the left, and a rear wheel it's on the right. If you change between front and rear the calculator will swap the values for spoke distribution, cross and spoke diameter to the other side.
Option: straight pull hub
The straight pull hub must be triplet specific.
This option removes the spoke hole diameter from the data entry form and replaces it with spoke offset. The spoke offset is important, do not guess this entry.
G3 Lacing
This is a triplet lacing pattern used by Campagnolo on their G3 wheelsets.
Any triplet specific J bend hub can be used for G3 lacing.
Straight pull hubs must be G3 specific.
The rim must be G3 specific with the rim holes drilled in groups of 3.
There is an extra rim dimension for G3 lacing, click "G3 Rim dimension" in the data form for additional notes.
Rim Erd measurement
If the wheel has an odd number of spokes, then the measuring holes will not be directly across the rim diameter. There are two ways of obtaining the erd:
- Use a small washer under one of the measuring spokes, and measure from the rim valve hole to the exact opposite spoke hole. Depending on the thickness of the washer and how the nipple sits in it, there may be a tiny difference to the true erd, but the effect on the spoke lengths will be negligible.
- Use the Erd helper. View the Erd help text and follow the instructions.
Or do both, and compare the results.
Rear wheels
Campagnolo G3 rear disc brake wheels use radial lacing on the disc side, but Campagnolo have designed a stiff hub shell that transmits the brake force to the crossed side of the wheel. You are not obliged to use radial on the rear disc side (left side) and can use a cross lacing pattern, but be aware that G3 rims will be drilled with directional drilling that assumes a radial inner spoke. If you use a cross pattern you will lose the parallel appearance (use the Geometry option to see the effect).
Front and Rear
For a front wheel, the "2" side is on the left, and a rear wheel it's on the right. If you change between front and rear the calculator will swap the values for spoke distribution, cross and spoke diameter to the other side.
Option: straight pull hub
A standard triplet straight pull hub cannot be used, it must be GS specific.
This option removes the spoke hole diameter from the data entry form and replaces it with spoke offset. The spoke offset is important, do not guess this entry.
Eccentric wheel
The hub is offset from the centre of the wheel.
The wheel will require many spoke lengths and these are shown in a table and grouped in the order of lacing.
Lacing guide
To help you lace the wheel you should study the wheel drawing. Start by selecting the right side leading spokes with guides displayed, and note where the valve position is (shown as the red dot). Show the spoke numbers by clicking the checkbox.
For a radial wheel do not select Leading or Trailing, just look at one complete side at a time. If you do select leading or trailing, then the diagram will not be as you expect, but it is correct.
Rotated wheel
The rotated wheel type is essentially for studying wheel geometry.
It is based on a Normal wheel, but allows you to specify custom rotations and pair angles.
A normal wheel has the following settings:
- Paired hub and rim checkboxes - un checked
- Hub and rim rotate, set to the value shown to the right (once a spoke count is selected)
- Relative rotate, zero
- Valve rotate, zero
- With these settings, all the spoke lengths will be the same and match those for a normal wheel
How to procede...
When you get totally lost, just reset the rotations back to Normal, and start again.
You need to study one side of the drawing with guides showing, and observe how it changes as the rotation values change, then look at both sides together. If you are only interested in the geometry, then use a hub diameter of 100 and a rim erd 550 to make things easier to see, you can also use zoom view to take a closer look.
Then start introducing more rotations by selecting the Paired hub holes and Paired rim holes, both of these will allow you to close up (rotate) the spoke holes on the same side (of the hub or rim).
Possible uses for all this
- Using a hub taken from a wheel that used a rim with paired spokes, and you want to rebuild the hub into a normal rim (see the notes for Hub rotate).
- Creating a lacing pattern where the spokes are grouped in 4's. You can simulate this lacing pattern and it will test your ability to understand wheel geometry, however the group 4 pattern now has its own seperate wheel type using simplified inputs. Here's a test for you, get both wheel types to display the same spoke length table, do that and you a a wheel geometry super star!
Rim valve hole
The rim valve hole position may appear in an unfavorable position in certain wheel configurations and you will have to manually adjust the position using the Valve rotate value (you must read the help topic for Valve rotate).
Caution!
Anything you create here is likely to be un-buildable!
- If the hub rotation angle is different to the value on the immediate right, then you've created a non standard hub that doesn't exist (unless you plan to make a specific one yourself). Same goes for paired hub holes.
- There are a few options when it comes to rims, because some rim makers will drill the rim to your specification. However, just because you can, doesn't mean you are going to end up with a wheel that is safe to ride, so be careful very with your creations! See the warning in the book.
- Some radial configurations will create one side where all the spokes are the same orientation, and it will try to twist the hub along the hub body when you start building it. And some configurations will create the same spoke orientation on both sides, which is totally impossible to build. So always check the spoke length table and see if one side is either all leading or all trailing.
Many configurations will require non standard hubs and rims which don't exist.
Mismatched hub and rim
The hub and rim have different hole counts.
All the spoke holes in the rim are used, this is important because missing out rim holes can lead to large gaps, and the unsupported region may not be stiff enough to cope. There will be unused holes in the hub, not a problem.
Lacing instructions
Print your worksheet. There's an empty column for you to write down your spoke lengths.
- View the drawing
- Select Right side, Leading
- Select 'Spoke numbers'
- Zoom view may help
- The blue dots are hub holes not used, you might want to tie some string through these to clearly identify them
- Lace the Right side Leading spokes, start with the spoke to the left of the valve hole (spoke 1)
- Uncheck Right (to show all Leading spokes)
- Select Left green
- Lace all the Left Leading spokes
- Select Trailing.
- Lace the right side trailing spokes, followed by the left
Make sure you look up your spoke length in the correct table!
Spokes in groups of 4
The rim is non standard where the spoke holes are in groups of 4. These rims are not common, but do exist.
The hub is nothing special and any hub can be used, including hubs with paired spoke holes. Note, these are standard hubs where the spoke holes on opposite flanges are offset one half hole pitch relative to each other (paired hole hubs are offset the same).
There will always be two spoke lengths per side. If spoke rounding allows you to select equal lengths (on the same side), then you don't tighten every spoke the same amount, maybe initially, but as tension increases you'll need to tighten leading/trailing different amounts which should become obvious when balancing the spoke tensions. The only way you will get the exact same spoke length per side is if you use a custom drilled hub where the spoke holes on the hub flanges are aligned appropriately. If you do use a custom hub then you cannot use the wheel type here for spoke lengths, but it can be done with the Rotated wheel type (although you need to really understand wheel geometry).
Always study the drawing when lacing. Select spoke numbering and look at one side at a time, start by showing leading spokes and these are the first spokes you lace. Look at the spoke table and choose the correct spoke! Choose the correct rim hole for spoke #1 (which is different on each lacing option).
If you want to align the valve hole using the method shown in the book (you should always do this), then with Option 1 lacing it's slightly different. Follow the guide in the book, and the position for the first spoke you place in the hub is cross pattern+1. You can see why if you study the calculator drawing with right side leading and guides showing, and visualise where the hub label will be.
Rim Erd measurement
If the wheel has an odd number of spoke groups (20, 28, 36 spokes), then the measuring holes will not be directly across the rim diameter. To obtain the erd use the Erd helper. View the Erd help text and follow the instructions.
The Erd helper is not actually required on G4 spoke counts that give an even number of spoke groupings, but measuring rim holes are shown to assist you when placing the measuring spokes.
Flange offset
The distance from the hub centre line to the centre of the Left and Right flanges. Shown as dimensions L and R in this diagram.

Offset calculator
Hub width | x | y | |||
F | L | R | |||
Always check your offsets. Measure between the hub flanges (dimension F) and it should be the same as the value shown in the form.
The above calculation does this...
L = h - x
R = h - y
F = L + R
Where h = half the hub width.
Hub diameter
For normal hubs, this is the diameter of the hub flange measured spoke hole centre to centre, sometimes referred to as the PCD (pitch circle diameter).
Straight pull hubs
For radial straight pull hubs, the diameter is measured at the position where the spoke seats.
For cross laced straight pull hubs, the measurement is taken at the extended crossing point of two spokes. If the spokes are close to tangent then the diameter can be measured to the centre of the spoke holes. A small error when measuring the diameter on cross laced wheels will not affect the spoke lengths.

Straight pull 20,28,36 utility
As mentioned in the book, an odd number of posts makes it tricky to measure the diameter and that a calculation utility for doing this would be available here...
todo :)
Spoke hole diameter
The diameter of the spoke holes in the hub.
Good quality hubs have a spoke hole diameter of around 2.5mm or 2.6mm. You don't measure this yourself, it's usually available on the hub manufacturers website. If you can't find it (or don't want to bother looking) then use 2.6mm. Let's say you used 2.6 and the value should have been 2.5 or 2.7, the spoke length error would only be 0.05mm.
Eccentric offset
The amount the hub is offset from the centre of the wheel.
Cross reduction
Large eccentric offsets, large hub diameters and small rim diameters can result in spoke head overlap on the hub flange where the shorter spokes are located, so reducing the cross on those spokes will improve things.
Selecting cross reduction will reduce the number of crosses by one at the bottom of the wheel. The number of spokes affected is determined by the number of spokes in the wheel.
Only use cross reduction if it's really necessary (due to spoke head overlap), and if you do decide to use it, study the lacing drawing carefully. The alternate strategy is to not use cross reduction and simply reduce the number of crosses (of the whole wheel), and use the simpler lacing method.
Spoke offset
This is only used on straightpull hubs.
The measurement is taken from the centre line to where the spoke head seats. It can be either positive, negative or zero depending on the hub design. For a negative offset enter the value with a - (minus) sign.
For a radially laced straight pull hub, the offset is zero.
It is important to use an accurate measurement for the spoke offset because it directly influences the spoke length, for example a measuring error of 1mm will result in 1mm error in the spoke length. The offset is difficult to measure yourself and the hub manufacturer should give you this value.

Positive offset

Negative offset
A hub with paired spoke holes
This will close up the hub holes on the hub flange.
Paired dimension
There are two ways of specifying the dimension of the paired hub.
- Enter the pair angle in degrees. The hub manufacturer often provides this value.
- Enter the measurement across the paired holes in mm. If you don't have the angle in degrees from the manufacturer, then use this method.
The same values are used for both left and right sides.
Paired lacing pattern
There are two ways of lacing a paired hub. Each option requires different spoke lengths and makes a visually different lacing pattern. Use the drawing to see the differences.

todo make some better pictures!
A rim with paired spoke holes
This will close up the rim holes on the same side of the rim.
The measurement is taken on a pair of rim holes on the same side.
- Enter the pair angle in degrees or
- Enter the measurement in mm across the paired holes
The same values are used for both left and right sides.
Option 1 or 2
There are two ways of lacing a paired rim. Each option requires different spoke lengths and makes a visually different lacing pattern.
Rim ERD
The Effective Rim Diameter.
The most important dimension for accurate spoke lengths.
The calculator will calculate spoke lengths to reach the erd measurement.
Measure the ERD using the tools and procedure shown in the wheelbuilding book.
If you are building a rim with a concealed spoke bed see the book for the method of obtaining the ERD.
If you use your own method of measuring the rim erd (including commercial erd "measuring tools"), or use a published figure you came across, then the calculated spoke lengths might be wrong and you are on your own. Good luck.
Erd helper
This is for obtaining the erd when the measuring holes are not directly across the rim diameter. This applies to Triplet and G3 wheels with an odd number of spokes. The erd helper also applies to Group4 wheels (see the Type help for more information).
Although not applicable to Normal wheels, the Erd helper is activated on these wheels and some off centre measuring holes are shown. This is for you to see how it works, and for you to give it a go.
To use the helper:
- Enter your wheel data, including any value for the erd. You only need correct entries for spoke count, G3 width and G4 width.
- View the drawing, and use your erd tools to measure across the marked rim holes
- Now adjust the erd value until the value below matches your measurement
The value in the brackets is the angle the measuring spoke takes when it leaves the rim. If the angle is greater that 12 degrees then the nipple will not swivel enough and it will give a wrong measurement (the nipple will lift up in the rim). For angles greater than 12 degrees you need to use the modified erd measuring tools.
Asymmetric rims
If your rim is an asymmetric design with an offset spoke bed, then specify the amount of offset here. The rim manufacturer will tell you the amount of offset which is typically around 4mm.
The calculator uses the hub flange offsets to determine which way to orientate the rim to give the best left/right tension ratio. You can see what it does if you look at the calculation Log. When the left/right flange offsets are very similar the Asym rim can make the tension balance worse, so always look at the tension ratio before and after specifying the Asym value, and in some situations a non Asym rim would be better.
Important
You must always follow the advised rim orientation because the left/right spoke lengths are based on this.
Asymmetric rim position
This is only shown for 2:1 wheels (Triplet or G3).
A selection is only required if you are using an Asym rim (and specified an Asym value), otherwise it is ignored.
For all the other types of wheels, the calculator knows which way to orientate the asymmetric rim, but it's not that straight forward for 2:1 wheels. The left/right spoke tensions on 2:1 wheels are different compared to the other wheels (with the same spoke count either side). It's actually very difficult to program the logic into the calculator and make the choice for you, and there may be no correct or wrong way to position the rim! So you need to check the output by trying each option and choose which way yourself.
Try one way and take a look at the resulting tension ratio which may look good. Then take a look at the Log to see how the asym rim was processed. Look at the modified flange offsets, where it could have reduced the short side and made it too short.
Try the other way. The tension balance my not be quite as good, but the flange offsets look good. It doesn't matter if you see the 100% tension flipping over to the other side, that's due to the geometry of 2:1 lacing, it's the ratio on the other side that matters.
You need to do this for both front and rear wheels, and the Asym position could be different for each.
What to look for
Ideally you want the best tension ratio with the widest left/right hub flange offsets, anything less than 20mm on an offset is not ideal. You can compromise on the tension ratio as long as it doesn't fall too low, say below 70%
Best Option : choose a non Asym rim!
Many 2:1 hubs have their hub flange offsets designed to give the optimum tension ratio and flange offsets when a normal rim is used (or a tiny asym offset of around 2mm). If you are playing around with your Asym rim flipping it around in the calculator, try it without the Asym value (a normal rim) and see how it looks. It could be the best option, and the Asym rim makes the tension ratio worse.
Width between holes
If there is a measurable gap between the left and right spoke holes then enter it here.

Most rims are centrally drilled or directionally drilled and for these rims the width between the holes is zero (leave the entry blank). If you can see a left/right hole stagger of 2mm or greater, then enter the value here. If you can't see anything obvious, then the entry is zero (or blank).
Some fatbike rims have a double row of spoke holes. If the wheel is for an offset fatbike frame using just one row of spoke holes you must still enter the full width between the two rows. See the book for more information on spoke lengths for offset fatbike frames.
Lacing pattern
If a spoke hole width is specified, then the spoke length calculation assumes normal lacing where the spokes from the hub flange do not cross over to the opposite side of the rim. The exception is Fatbike wheels for offset frames (eg. Surly Pugsley), where the spokes are laced to the right hand set of rim holes (the calculation output will prompt you what to do).
Frame offset
An offset frame shifts the position of the rear hub outwards towards the right, which affects the spoke lengths. The frame manufacturer will tell you the offset value. An example of an offset frame is the Cannondale AI (Asymmetric Integration) frame, that has an offset of 6mm.
The more common symmetric frame has an offset of zero. If your frame is not offset, then uncheck the Frame offset option (any entered values are saved, but ignored).
If the required offset is not in the list, change the input to User Input in the system menu (Ξ).
Fatbike offset frames
Examples of Fatbike offset frames are the Surly Pugsley (offset 17.5mm) and the Surly Moonlander (offset 28mm). These offset frames use a standard 135mm freehub, and to achieve the correct tension balance you cannot use a rim with centrally drilled holes.
For a 17.5mm offset frame, use either an asym rim (more offset the better) or a fatbike rim with a double row of spoke holes. A 28mm offset frame requires a fatbike rim with a double row of spoke holes. Do some calculations and keep an eye on tension balance, and always read the notes displayed with the calculation.
Fatbike offset forks
Offset frames can have a matching offset fork. For example, the Surly Pugsley has two fork options, a 100mm symmetrical fork, and a 135mm 17.5mm offset fork. With an offset fork you actually build a wheel that is identical to the rear wheel, so for offset Fatbike front wheels, select a rear wheel in the selection list.
Spokes
The number of spokes in your wheel.
If the required number is not in the list, change the input to User Input in the system menu (Ξ).
Mismatched options
You need to read the help information for the wheel Type.
Select which combination you require.
Lacing cross pattern
If the required number is not in the list, change the input to User Input in the system menu (Ξ).
Radial lacing
For radial lacing select 0 cross.
When radial lacing a hub using J bend spokes, lace the spokes with the heads out (elbows in).
Straight pull hub cross pattern
With a straight pull hub you have no choice with the cross pattern because it's dictated by the hub design.
Shimano straight pull hub cross count
Shimano straight pull hub specifications may list the number of crosses incorrectly. See Shimano straight pull hubs at the end of the spoke length chapter.
Spoke diameter
It is important to specify the correct diameter for the spokes you are using. The diameter (in mm) is used to calculate the elastic elongation of the spoke which improves the spoke length accuracy.
For a butted (swaged) spoke, use the diameter of the central portion.
If the required diameter is not in the list, change the input to User Input in the system menu (Ξ).
Bladed spokes
Bladed spokes are made by flattening a round spoke. For a bladed spoke use the round spoke equivalent. For example:
Spoke | Diameter |
---|---|
Sapim CX-Ray | 1.5 |
DT Aerolite | 1.5 |
DT Aerocomp | 1.8 |
If your bladed spoke is not listed, then ask the spoke manufacturer what the diameter of the spoke is before being forged (their website doesn't usually specify this, so you need to ask).
Calculation log
Enter the required data for the selected wheel type.
After a calculation, the Log will show how the calculation was performed. If the calculation cannot be made, the Log will show an error message.
Worksheet
This will print a worksheet for use while you build your wheel.
Hub and rim names are advisable. Add them now (in the menu bar).
Any text you enter here will appear on the print.
Save to document
Format the calculation for saving in a word processor or spreadsheet.
Export the drawing
Export the wheel drawing to an svg file.
No drawing in view.
Select the display options and it will export the drawing exactly as shown.
The spoke lengths
The calculated lengths are the recommended minimum, so always round the fractional spoke lengths up.
You can round up by up to 2mm, which means you can always find an even or odd size spoke length, however, it is important that you measure the rim erd as advised in the book, and also specify the correct spoke diameter (see the Spoke dia help text).
Here are some examples of how you would select an even or odd size based on the calculated length.
Calculated | Even | Odd | |
---|---|---|---|
260.0 | 260 262 | 261 | 260 for the even side is the absolute minimum, but 262 will be easier to build. |
260.4 | 262 | 261 | Do not choose 260 for the even size because it will be too short. |
260.8 | 262 | 261 | Easy choices to make here. |
261.0 | 262 | 261 263 | 261 for the odd side is the absolute minimum, but 263 will be easier to build. |
261.2 | 262 | 263 | Do not choose 261 for the odd size because it will be too short. |
If you are borderline on a selection and not sure which way to go, then double check your rim erd measurement. Correcting a small error in the erd may make your spoke length choice easier.
Radial lacing
You should lace a radial wheel with the spoke heads out (elbows in), doing it the other way (heads in) puts more stress on the hub flange as the spoke is pulled over it. With all the spokes lying on the inside, the hub flange offset distance is reduced, and for radial lacing the calculator will subtract 2mm from your flange offset dimension. You can see this is the calculation log.
Spoke head clearance
The distance between the spoke and the head of the adjacent spoke.
As the number of crosses increases, the spoke moves closer to the head of the adjacent spoke until it touches (clearance zero), then overlaps it (clearance negative). The overlap should be avoided because it puts an unnecessary bend in the spoke close to the elbow, and it also interferes when placing the spokes in the hub.

Touching

Overlap
If the spoke head clearance overlaps by a small amount of around -0.5, then it still should be okay, anything more then it's not advisable.
Rim entry angle
The angle the spoke makes when entering the rim.

Standard nipples can swivel about 6 or 7 degrees. Nipples with a spherical design such as the Sapim Polyax and DT ProHead can swivel more (9 degrees for the Polyax).
For your hub, rim and spoke count, choose a cross pattern that results in a spoke entry angle of no more than 8 degrees, otherwise the stress on the spoke threads can result in fatigue failures (the spoke could snap at the threads).
Some rims are drilled at an angle to allow the spoke to follow the natural spoke line, in which case the spoke entry angle is not an issue. Examples of this are the WTB rims with 4D angled drilling.
Rim entry angle - combined
This is the actual angle the spoke takes when it enters the rim and takes into account the hub flange offset. It combines the rim entry angle and the bracing angle.
It will be larger than the Rim entry angle, however the rim spoke holes are usually drilled and aligned towards the hub flange for a natural spoke line, so you should not be concerned about large angles and the nipple not being able to swivel enough.
Tangent angle
The angle the spoke makes at the hub flange. A radial wheel will be zero degrees, and as the cross count increases so does the angle. 90 degrees will be fully tangent.
Lever arm
The measurement which is 90 degrees from the extended spoke line to the centre of the hub, shown as the red line in the diagram.
This data value is only shown here because it's easy for the calculator to do! Some people like to think the lever arm plays an important roll in transferring drive and brake torque, large lever arms being better. But in reality, as long as the wheel is not radial (lever arm zero), then the wheel will transfer torque. Select the number of crosses as advised in the book and everything will be fine. Lever arm is a none issue!
Bracing angle
Picture required.
Although I'm sure you know what bracing angle is.
Tension ratio
This is the ratio between the left and right side spoke tensions. For example, if the spoke tension on the 100% side of the wheel is 120kg and the other side is 60%, then the tension in that side would be 72kg.
This is for information only. When you build your wheel, this is how it will turn out. Tension ratio is calculated using the hub flange offsets and the spoke lengths. There is nothing you can do during building that will affect this ratio.
Left / Right
Left and right is from the perspective of the rider.
Left side
Sometimes referred to as the non drive side.
For disc brake wheels, the disc rotor is located on the left side.
Right side
Sometimes referred to as the drive side (where the chain and sprockets are).
Triplet spoke count
The number of spokes in your triplet wheel.
There are twice as many spokes on one side of the wheel than the other. Rear wheels have the greater spoke count on the right side (drive side), and front wheels the greater spoke count is on the left (disc brake side).
The spoke distribution between the left and right side is shown adjacent to the spoke count. If you change the wheel between front and rear, the spoke distribution will change (cross and spoke diameter will also be changed over).
Triplet lace option
There are two ways of lacing a triplet wheel, and each way requires different spoke lengths. Make your calculation, then use the "Draw" menu option to study how to lace it.
Hubs
For hubs that use J bend spokes, you can choose either lacing option.
For straight pull hubs the lacing option is determined by the hub design. See Triplet lacing in the Wheel design chapter which describes how to identify the required lace option.
Rims
If you purchase a rim that is designed for triplet lacing it will have a specific directional left/right spoke hole drilling, for example a 24 spoke triplet rim will have 16 spokes pointing one way and 8 pointing the other. Depending on how the spoke holes are drilled in relation to the valve hole will determine which lacing option to use. A rim drilled for option 1 will have the valve hole between two spokes on the same side, and option 2 will have the valve hole between opposite side spokes. Use the Draw menu option to visualise this, it will help if you use the button Left Green.
Hub rotate
Angle in degrees.
The value is the angle between a spoke hole on one hub flange and the spoke hole on the other flange. In a normal hub, the two holes are rotated half a spoke hole pitch apart.
This is not the same as a conventional paired hub where the angle is between two hub holes on the same side.
The value shown on the right is the number of degrees for a normal hub (360/spokeCount). If the angle is zero then the holes on the hub flanges will be perfectly aligned.
Hub from a paired spoke wheel
This is a hub taken from a paired spoke wheel and you want to lace it into a rim with equally spaced spoke holes.
The hub spoke holes on the flanges may appear totally in line (rotation angle of zero). However, the angle will slightly more than zero, around 6 degrees to match the hole spacing in the paired rim the hub came from. There is no way of determining this without having the paired rim it came from. If you want to look at the paired spoked wheel, then set the Rim rotate to the same angle.
Rim rotate
Angle in degrees.
A normal rim has equally spaced spoke holes. This option allows you to rotate each side of the rim relative each other. They still have equally spaced holes per side, but appear paired, and allows a paired spoke lacing pattern with an appropriate hub (with the same rotation angle).
If the rotation angle is zero, then the left and right side holes will be adjacent to each other (which is only possible if the width between the holes is wide enough). The value shown on the right is the number of degrees in an equally spaced rim (360/spokeCount). For paired lacing the angle is somewhere around 6 degrees although without having the paired rim it's only a guess.
If you are lacing a paired hub into a rim with equally spaced holes, leave the rim rotate angle as indicated on the right.
Relative rotate
Angle in degrees.
This is the hub and rim rotating relative to each other.
Think of it as grabbing the hub and twisting it in the wheel.
It will start to change the visual cross pattern.
Valve rotate
Angle in degrees.
This moves the position of the rim valve hole.
Some configurations you end up with may have the valve hole in the wrong position, so adjust the position manually.
The spoke numbers do not change. When first drawn (or the value set at zero), the number 1 spokes are to the left of the valve hole, but can move to other locations as the valve angle changes, so be careful when lacing and choosing the correct spokes.
Be aware that for type 1 rims with with an offset left/right stagger, the rim hole immediately to the left of the valve hole needs to be a right side spoke.
G3 Rim dimension
The width of the spoke group measured at the nipple seat of the rim.
G4 Rim dimension
The width of the spoke group in mm measured at the nipple seat of the rim.
Option 1 or 2
There are two ways of lacing the wheel, each option requires different spoke lengths and makes a visually different lacing pattern.
Information data strings
Click the data string to copy it to the clipboard.
Calculation URL
Data file strings
For use with an external data file.
Hub and rim names are required. Add them now (in the menu bar).
Zoom
When the drawing is in view, zoom increases the diameter of the hub to make it easier to see the spoke placements on the hub flange. It is useful for studying wheel geometry, especially with one side in view and Guides selected. It is visual only, and doesn't alter the spoke length table.
If your actual hub is a very large diameter (compared to the rim) then Zoom will not increase it.
The Zoom option is only available on wheel types where it is useful.
Spoke numbers
Spoke numbers are shown for wheels that require multiple spoke lengths per side.
To identify the location of the spokes, view the drawing and select the appropriate side. Spoke numbers are only shown when one side is in view. The opposite side spoke table will be greyed out (to make sure you lookup your spoke in the correct table).
Spoke direction
To understand the direction view the drawing. The wheel is drawn looking on the Right side, and when in use it will move off to the right. Leading spokes Will lead (point forward) the rotation and Trailing spokes Will trail (lag behind) the rotation.
Leading spokes are also called pushing spokes, and trailing spokes called pulling.
DT Swiss hubs
Spoke lengths | |
Spoke type | |
Nipples used | |
Notes | |
Date | |
Calculator link |
Recalculate | Left | Right |
---|---|---|
Cross | ||
Spoke diameter | ||
Spoke lengths | ||
My selection | ||
Ideal length | ||
Alternative length | ||
Nipples used | ||
Spoke head clearance | ||
Rim entry angle | ||
Spoke tension ratio | ||
Rim combined angle | ||
Bracing angle | ||
Tangent angle | ||
Lever arm |
Left | |||||||||
---|---|---|---|---|---|---|---|---|---|
Spoke number | Spoke length | My choice | Spoke head clearance | Rim entry angle | Rim combined angle | Lever arm | Bracing angle | Tangent angle | Direction |
Right | |||||||||
---|---|---|---|---|---|---|---|---|---|
Spoke number | Spoke length | My choice | Spoke head clearance | Rim entry angle | Rim combined angle | Lever arm | Bracing angle | Tangent angle | Direction |
Read me!