Ron, pay particular attention to the time -lapse satelite photos for cloud patterns moving off the Pacific. Late December through February is a pretty iffy period to be going through the high country of NW Mexico.You may time it perfectly and have only crisp sunny weather but it can get awfully cold and snowy there, no fun on a motorcycle ( and I think you can get ample cold riding in northern British Columbia in summer)
As an example,on Feb 10 2002 ,travelling by car as I wouldn't have taken this risk on a bike, we left Durango after breakfast under brilliant cloudless skies and went north on Mex 23. By afternoon it was cloudy and we spent the night in Tepehuanes , elevation 1800m . Next morning it was snowing.Instead of retracing the road 170km south and around the mountains we kept going . At Cienega Escobar turning east it started to get real interesting as the road climbed to over 2400m , mountain grades , hairpins , no retaining walls and 4cm+ of freezing slush and building. Took 2 1/2 hours to travel the 110km to clearer roads at Santa Maria del Oro ,then to Mex 45 and Parral , still snowing .Finally left the whitening country after descending onto the desert and to Chihuahua. That night TV weather reports told that "Frente 31" had dumped much snow on all the Sierras and many roads had been closed for the time it would take to melt away.
The Copper Canyon country is much nicer during spring-summer-fall when everything is green. I went back in Septembert hat year on my bike - the mountain roads were a joy then.If I was you I would stick to the coastal route Mex 15 until Mazatlan , then check the interior weather to Durango. Then you ahve the option of avoiding the cold and going further south and to Guadalajara.
[This message has been edited by Sjoerd Bakker (edited 16 December 2005).]