How to find out spoke length?

combat_wombat

I am about to get the new Shimano DH-3N80 Dynamo hub from germany (they are a lot cheaper there)
+ no bike shop in the UK seems to have heard of them.
Now I have to buy some spokes - how do I find out what length I need - surely no spoke calculator will have this hub on it?

whyamihere

The DT Swiss spoke calculator at www.dtswiss.com has a couple of Shimano hub dynamos on, one disc, one not. I'd be 95% confident using that, as the measurements aren't likely to change much for the different models.

ajb

and if you want to double check because 95% isn't quite enough, you can always get pcd , flange distance etc from the Shimano website and enter these details to the DT Swiss spoke calculator rather than selecting a hub from the drop down menu

combat_wombat

I used the DTSwiss calc + choose their non disc hub Dynamo

Pitch circle diameter = 80.00mm
Flange distance = 29.00mm

but shimano say thier new (link at bottom) one is
Hole Reference (PCD) = 70mm
Flange Distance = 60mm

The PCD seems a reasonable change, but the Flange Distance is more than double!
+ it can't be bigger as it's meant to be a lighter hub.
I guess shimano's measurement is a Diameter + the DT use radii? - but I can't really believe there would be a muddle of use?


http://cycle.shimano-eu.com/catalog/cycle/products/component.jsp?PRODUCT%3C%3Eprd_id=845524441788193&FOLDER%3C%3Efolder_id=2534374302050085&ASSORTMENT%3C%3East_id=1408474395181667&bmUID=1197271544826

whyamihere

The Shimano measurement has to be wrong. The flange distance is the distance from the centre line of the hube (above which would be the spoke) to the flange. The width of a front hub is 100mm between the locknuts, therefore Shimano are saying that their flanges are 20mm wider apart than the axle! I can only assume that they mean the total distance, instead of the halfway distance, but it's a pretty bad measurement.

graemetherunner

any update on this as I'm trying to work out the same & the shimano site seems to have changed...

spoke hole circle - 74mm (assume thats pcd)
flange distance isn't listed.

Stellite

try this

http://www.sheldonbrown.com/rinard/spocalc.htm

Stellite

Or this

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

I would measure yourself with a vernier caliper rather than taking sizes for grantd, especially if you are using expensive spokes.

Or take the hub and rim to a LBS and get them to measure it, and buy the spokes from them, if they mess the size up they will change them for you.

redvee

I laced a wheel with an On One SS hub and had to get all the measurements. Even though I could read a set of verniers it was still a challenge but worthy when the wheel was complete, alas not by me though. As I didn't have a wheeljig or dishing tool or the patience I let the LBS finish it off for £8.