I bought the same bike to do the same trip you are possibly doing, in 2002.
Great bike, I fell so many times in Siberia, Mongolia and Kazahkstan but the thing always got up and continued without complaints, cant say that for my legs though... You wont be dissapointed, it got me all the way to Spain without one hiccup.
The GPS didnt work in Russia.
It was working when I was riding out of Vladivostok, I was well chuffed I can tell you.
It stopped working when I was going through a small military town just south of Xhavarovsk(sp?) north of Vlad. I wasnt sure but I was humouring myself that russian sattelites fried my japanese GPS on purpose, these things go through your mind when your alone on the road dont they?
In reality I didnt need the GPS the whole trip anyway.
I hope the track from Xhavarovsk to Chita is better for you now than it was for me back then, or perhaps thats what you are after. One section was particularly tough but it was only 200m or so. Still it took me 7hours to get through it though.
Enjoy the trip, russia is great.