For the Miche Primato Large Flange hubs on Mavic Open Pro's i get 293.0mm for the front and 293.4mm for the rear so i'd order 292mm spokes.
As for the Gran Compe i believe them to be decent hubs, but no better than formulas which in my opinion are a good benchmark for cheaper hubs. Have a look at Planet X Pista hubs - i built a set of these onto open pro's and they're good hubs, basically an unbranded Gran Compe.
Hope that helps.
Thanks, 'Racer!
And cheers for heads-up regarding Gran Compes. Will grab the Miches.
Thanks, 'Racer!
And cheers for heads-up regarding Gran Compes. Will grab the Miches.