hi guys,,just happened to cruise the new posts and found this well worn topic,,,
here's a thread that shares the experience of folks having ridden on 19/17 and then tried the 21''
check out what jimmy lewis one of several adv/dual-sport riding gurus,,i\first american to podium ona bmw in the paris/dakar rallye several years ago,,,test/development rider for BMWs HP-2 project and learn to ride maestro...has to say not to mention his wife Heather even commented on her experience in post #106
i tend to create solutions that you will appreciate in real world riding....
so tell me/us what ya noticed whe riding your bike with different wheel diameters on different types of terrain....