According to the UK brochure, it's 180mm standard (155mm for Greenline models). OK for firm beaches, muddy paddocks, forest roads, easy fire trails, but would be vulnerable to deep soft sand (especially with low profile tyres), large rocks, deep ruts, fallen logs or even big erosion mounds. Even so, that is probably enough for most people's needs - just need to be aware of the limitations.
Interesting that you have seen so few of the Yetis in Europe. People at Briskoda report the same thing. Skoda have built more than 100,000 so far. Where are they all?
Bookmarks