There is a shipping service to Magadan vis a vis S.Korea via Vladivostok, by FESCO.
If you look at their sailing maps,, one could ride upto Magadan then have their bike shipped to S.Korea or arrive to S.Korea then ship the bike to Magadan,, then take the Korean air or Russian air to Vladivostok then catch the propjet upto Magadan and start the journey south from there.
It is container only ,, USD 2,600 for one 20 ft container. So for two or more bikes it makes sense.
Wendy at Riding Pointers in Korea can hep you with this.
Or FESCO Magadan man is Mr. Dong Jin JANG
Djjang@fesco.com +82 2 3702 2056
FESCO LINES KOREA CO,. LTD
FESCO LINES KOREA CO,. LTD
I also understand FESCO sails out of Everette, Wasington, USA a lumber town ,, into Vladivostok then ,, feeders onto Magadan,, sharing with Han Jin ,, Korean shippping line. USD 4,500 to 6,000 was mentioned for a 20 footer.
In fact ,, FESCO can also ship your bike to Europe from Vladivostok by rail, under their inter-modial plan.