spoke lengths

I’ve had expensive trouble with online spoke calculators before.
Could anyone be awesome and tell me the spoke length I’ll need to lace a B43 to to a 32h novatec hub? :smiley:

Take it to the shop you’re buying the spokes from and get them to measure it up. THen if it’s wrong they’ll have to replace em. If you’re buying spokes online… don’t.

To be more specific
Rim ERD = 522mm
Flange hole diameter = 62.8mm
Hub width = 59.8
lacing in three cross

dere is a program called spocalc.xls floating around teh interwebs, I has used it before to build teh wheelz and it waz good

What numbers is the online calculator giving you? And how exactly are you measuring them? I got sick of the DT Swiss calculator giving me spoke lengths that were either too long or too short, and websites that incorrectly quoted ERD’s. Spocalc.xls is a little bit better, but from memory spocalc.xls rounds spoke lengths to the learest millimeter (I’d like the option of rounding myself!). The database is a good idea, but I found that a lot of the hubs were outdated and the newer model of those hubs had slightly different dimensions, so there were a heap of components that I’d never use.

So, I put my maths to good use and made a spoke calculator in excel, from scratch, with complete readouts for different lacing patterns, a database of hubs, rims and spokes, with prices and weights, and added a sheet called ‘wheelset builder’, which lets me choose a hub, a rim, a spoke type, and it will tell me how much it will cost, and how much it will weigh, as well as left and right spoke lengths for different lacing patterns. I then have a diary where I keep track of every wheel I build, as well as all the components I used, it’s the only way to keep track of it all. (Pretty nerdy I know, but I got sick of the other calcs after building a few sets)

It gives really good results, but the problem I think you’re facing right now is that you’ve got spokes that are around 3-4mm too short, yes? The ERD of a B43 is actually 558mm, not 522mm (did you mean 552mm?). From memory, the B43 ERD on the Velocity website is 552mm, but it’s actually 558mm (This is to the top of the nipple head).
Give us a sec, I’ll go work it out.

EDIT: I read the numbers wrong, so I’ll try again. The above picture is CORRECT, and gives a spoke length of 269.21mm for 3X lacing. Round up to 270mm.

This will give you spokes that come right to the top of the nipples, which is what you want!
PLEASE keep in mind though, that my calculator is designed to work with hubs that I’ve measured myself. Ie, my measuring methods give slightly different values to those that you’ll find on websites, and it’s because, as an example, when I measure the spoke hole diameter, I don’t measure to the centre of the hole, I measure to the centre of the spoke when it’s being pulled out from the hub (it’s only a little bit different, but the centre of the spoke is slightly off centre to the centre of the spoke hole. Also, my hub flange width is not taken from the centre of hub flanges, but rather slightly wider, even to the outer edge of the hub flange (otherwise the spokes on the outside of the hub flange can end up being too short)

270mm sounds about right for a 32h B43 laced 3X to a track hub, and is the same as what I’d use for a 32 spoke B43 using a Velocity hub, so I’d say the measurements you gave me were close enough.

Hope this helps,
B

Thanks so much wheel works :smiley:
270mm was about what I guessed whilst measuring by ruler against a built up wheel set. And I was getting 252mm on the calculators. must have been the ERD :expressionless:

Your calculator sounds awesome and very thorough.

Thanks!

all the same, What Bender said

here is a nice video relevant to the topic
http://www.youtube.com/watch?v=WDzoZshH88c