Building with factory hubs

munkster

Mostly hypothetical Q - because I don't need any more wheels - but can anyone outline the pitfalls of rebuilding onto a pair of Dura Ace factory hubs*? I'm guessing that the spokes are straight pull but other than that can I assume that the rims and spokes can just be supplanted with appropriate third party ones or are the spoke heads proprietary in some way?

* like the ones on wheels for sale in the classifieds at the moment, for example!

ugo.santalucia

There are a few issues

1) Calculating spoke length

2) Finding rims in 18-20 holes count that are worth building

3) Finding the spokes you want in the length you need

munkster

Calculating spoke length because I'd have to basically measure the hub dimensions myself I guess?

Think the front is 16 hole as well, so that makes it even more of a challenge to find rims! Kinlin XR-300 is an option I suppose, would need to research it.

So, in conclusion, likely to be a PITA. Thought so, ta! ;-)

ugo.santalucia

munkster wrote:

Calculating spoke length because I'd have to basically measure the hub dimensions myself I guess?

For radial is easy, but how do you calculate the rear? What pattern do they use? It's not very clear

sirmol

Can you not 'cut out' the current spokes and treat the hubs as if you have bought them i.e. measure and work out spoke length once you have chosen the rim?

munkster

but how do you calculate the rear? What pattern do they use? It's not very clear

Dunno? Looks like "1x" if you don't count the one that the spoke "crosses" immediately after it leaves the flange hole. Presume they don't actually come into contact since they are separated laterally...

http://www.wigglestatic.com/product-med ... h=2000&a=7

But either way I am guessing that spoke lengths won't be calculable via "conventional" means. Would be an interesting project but has the potential to become painful perhaps!

andy_wrx

Lace it up with string and then measure that !

munkster

You sir are a genius. Why don't all the wheel building guides suggest this method I wonder? :shock:

Moot point now anyway, someone's bought those wheels.

ugo.santalucia

munkster wrote:

You sir are a genius. Why don't all the wheel building guides suggest this method I wonder? :shock:

Moot point now anyway, someone's bought those wheels.

Because it's unlikely to be a reliable method

munkster

Umm, I *was* kidding...

cycleclinic

Straight pull hubs need a fractional crossing number to calculate the spoke lengths for a crossed pattern. For example miche supertype use 2x lacing for the ds rear fractional crossing is 2.8 how do I know trail and error when building with them. Straight pull spokes are expensive so you need a good stock to experiment with.