How to calc spoke lengths for wheel build

dhobiwallah

Having a bit of trouble working out what spokes to buy to have a first crack at a wheel build.

I have a Shimano HB-M555 rescued from a wheel I Taco'd last year and an old non-disc XC wheel that I would like to re-use the Mavic 217 rims from (because I'm Pikey before everyone asks).

Only prob is I'm getting confused trying to use online calculators - not least because the hubs don't have the simple 'pie dish full of holes' type flange on either side.

Random hungarian website - but has a picture!
http://ebike.hu/termekek/kerek/agy-elso/disc/7505+shimano+deore01+hbm555/

From shimano tech docs the hub specs are:

MODEL # HB-M555*
WEIGHT 236g
FLANGE DIAMETER 37.8mm(L) 44.2mm(R)
SIS COMPATIBILITY

---

OVER LOCK NUT DIMENSION 100mm
CENTER TO FLANGE (L) 33.5mm
CENTER TO FLANGE (R) 25.7mm

* On large flange side, subtract 1.5mm from spoke length. On small flange side, add 1.5mm to spoke length.

Specs for the rim I have found are:

Mavic 217 (ERD is Mavic's Nipple Seat Dia + 3mm for nipples) (26" MTB)

Effective rim diameter (ERD) 539.0 mm
Offset spoke bed (OSB) 0.0 mm

Can anyone help me work out what length spokes (and nipples) I need?

Using the sitehttp://www.wheelpro.co.uk/spokecalc/

And inputting the 'ERD' as the 'rim dimension' (ignoring the 3mm mentioned)

the basic length for a 3x came out at 263.5 - I'm guessing I need 16 spokes at 265 and 16 spokes at 262 :?: What length nipples should I get?

redvee

Had a look at wheelpro spoke calulator

http://www.wheelpro.co.uk/spokecalc/

dhobiwallah

Thanks for the reply - we crossed posts as I updated to complete my post with my result from that very site!

dhobiwallah

And just noticed spokes only seem to come in 2mm increments, so do I go 1mm longer or 1mm shorter than my calculation of 265mm???

schweiz

longer

dhobiwallah

Thanks!

nicklouse

try reading this
http://www.shimano.com/publish/content/ ... le.html/07)%20Hub%20Specs.pdf

dhobiwallah

The link is a bit corrupted, but I think its
http://www.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.download.html

If it is the hub section then that is where I got the initial hub info from (but google got me there direct - I didn't go via the shimano website), or is there one on wheel building itself that I've missed? Either way thanks for digging that out - some other useful (unrelated) info on there too ....

cycleclinic

Measure the ERD your self. Sheldon brown has a good guide to doing this and also you can download spoc clac as an excel spreadsheet from this site.

http://sheldonbrown.com/rinard/spocalc.htm
I use this to build wheels. Also it is a good idea to measure the hub yourself too but shimano do state correct dimensions. Some manufacturers do however have different ideas of how flange to centre spacings are measured. Thankfully it makes little difference to the spoke lenghts.