The evilness of wheel spoke sizing

bobbydigital

I must have spent days trying to work out what size spokes I need, reading web pages of guides, watching videos of people explain it all, even using the spoke calculators that allow you to put your rim and hub information, well they all come out with different sizes and it's a good 20mm difference.

If anyone can help I would really appreciate it.

My rims are Mavic xm319 Disc 26" 599 x 19c, 32 spoke, Alu 6000.

http://www.tredz.co.uk/.Mavic-XM319-Disc-26-MTB-Rim_58374.htm?sku=165950&utm_source=google&utm_medium=cpc&utm_campaign=google_shopping&gclid=Cj0KEQiAot_FBRCqt8jVsoDKoZABEiQAqFL76EWc6q3qZAWTnUEuuaJt8Yak0WbAVfdUOrNewOFIt_EaAgZc8P8HAQ#


Rear hub is a Shimano XT Deore FH-M756A

http://www.chainreactioncycles.com/shimano-deore-xt-disc-hub-rear-m756a/rp-prod3987


Front hub XT Deore HB-M756

http://www.chainreactioncycles.com/shimano-xt-disc-hub-front-m756/rp-prod3986

Rightarmbad

Need to know what spoke type to calculate.
Something like a double butted spoke needs to be shorter, as does a thinner gauge.
Also need nipple length you need for that rim.

I suggest that if you cannot figure out the spoke length with all the full specifications and all the online help available that maybe building the wheel is simply beyond you.

cooldad

Why would DB spokes need to be longer?

The spokes need to be the right length, whatever type they are.

Rightarmbad

cooldad wrote:

Why would DB spokes need to be longer?

The spokes need to be the right length, whatever type they are.

Usiing something like CXray spokes are generally sized 2mm shorter to make up for spoke sttretch once built.
15 guage are always sized smaller than 14 guage.

Thinner spokes stretch more and some spoke compositions stretch more than others.

Rightarmbad

You can check this yourself by trying out the DT calculaor.
Change out various spokes and see what length it suggests.

cooldad

I did not know that, but you seem to contradict yourself between posts. Longer in the first and shorter in the second.

The Rookie

Use the DT Swiss calculator and it gives the same length regardless of butting. So does Roger Mussons book, so I'll stick with more experienced advice.

Flange dimensions from the manufacturer, rim ERD you measure (or for Mavic add 5mm to quoted), use the DT Swiss calculator it's easy and works.

bobbydigital

Why do you need add 5mm for the Mavic ERD?

I'd be going for 12mm nipples with 2.0mm spokes, I've seen some stainless steel Halo spokes I wanted to use on ebay.

That's all I know, I've only every laced one wheel before and that was using the previous spokes but swapping out an old hub as it was cheaper to buy a new hub than replace the free hub body on the original hub.

260mm left rear
258mm right rear

259mm left front
260mm right front.

Thanks for the replies.

The Rookie

Bobbydigital wrote:

Why do you need add 5mm for the Mavic ERD?

Because Mavic measure it to the nipple to rim seat interface but the spoke length should be to the top of the nipple which is about 2.5mm further out (so for diameter it's 2x2.5mm), you ideally measure it using a spoke and a nipple (which vary very little) you will be using but for Mavic they seem to be very consistent at +5mm on quoted.

bobbydigital

Okay thanks, I guess I can order some spokes now. Finally.