Why Copernik's trail?
Easy biking, althought somewhat sandy roads. Very nice Walcza river "canyon" (!) in Warmia region. Lot of churches!
Weather is very predictible in this region, and in end of July we had beautiful not too hot weather.
GPS is definitely recommended because in some places the trail is sparsely indicated. I saved the trail in the Garmin Mapsource file, and OziExplorer waypoints and tracks (Day 1 and Day 2) files.
Although the region (Warmia, north-east of Poland) is flat (post-glacial) the trail follows hills so the denivellations are definitely positive.
Mountain bike is needed because of sandy and sometimes weedy forest roads.
For finding lodging we used Lonely Planet "Poland" but there is many "agrotouristic" pensions in the region aimed at German visitors in the region.
Some links: Olsztynska Strona Rowerowa [and photo of Lyna hills], Maporama.com
Walsza river reserve
From the hotel's windows (rooms are just under the roof! on the last floor) we could see the cathedral (link). Food shops open in Poland at 6am so we bought some milk and bread, and prepared the "biker's breakfast" in the hotel. After Lidzbark Warminski the trail becomes more sandy, following flat forest routes. In Pieniezno (link in Polish) we stopped in a "bar" (excellent polish folklor :-) but pizza wasn't too good), the trail passes by the big church and soon dives into the beautiful Walsza river valley (reserve). It was very surprising to follow the river (or rather the stream) in seemingly mountainous setting (see the zigzagging profile from 35th km!). Many fallen trees blocks the trail, many small streams descend into the "gorge". In some places one must carry one's bike because of steep humid walls. We got very tired and got out of the canyon not following the trail. A man in the bar told us that one can sleep in the cloister (some photos and info here, in Polish) which seem to be also a museum.
Wanting to catch the train from Frombork we speeded up on slightly descending roads. Frombork is on Wisla bay and has a huge castle known for Copernic works. It tourned out that there was NO train from Frombork to Elblag :-) on this day of week instead lucky we catched a PKS bus to Elblag. The driver was very kind and helped us to put the bikes (without dismounting anything!) in the bus trunk (we had to pay a small supplement for this luggage). From the bus we saw lot of hills/forests. I think there is possibility to follow the Copernik trail from Frombork to Elblag but we had no time to do so. In Elblag the train station is just by the PKS bus station (last stop of the bus).
Here is the Ozi Explorer track.