This rack will not only carry 4" and 5" bikes . . . but will also carry roadies (Yea I have one) and mountain bike (I got one too). I have not tested it yet, but it looks like it will fit the new 5+" Vee Snowshow 2XL which comes in a tad under 5.5".
I really like the platform way of transporting bikes.
And I discovered this evening that it doubles as a great wash stand.