Let's offroad / mountain bike / mtb / ride dirt

I'm carrying my XL Honzo ESD (which the geo chart says should have a 1285mm wheelbase but it is slightly overforked so might be a bit higher) in a good old Proride 591, but with the following provisos,

1. I moved the bit with the arm back (to move the aluminium tray and front plastic wheel tray forward) further than Thule say you should.
   
2. Even with the above, the plastic tray for the front wheel was still hanging waaay off the front of the aluminium tray.
   
3. Even with both of the above, the front wheel was barely on plastic tray and the strap only just fit over the tyre.
   
4. Even with all of that, it had been fine for quite a few trips... but going up the a9 to the Cairngorms a couple weeks ago it was really windy and my front wheel pulled the plastic tray almost right out of the aluminium tray and the wheel flopped to 90deg. My solution for this was to turn the wheel 180 deg and that put it far enough back that the plastic tray engaged the aluminium tray completely and it's been fine like that since including driving around in the cairngorms and coming back down the a9 at the end of the week.
   
   

Thule says the max wheelbase for the 591 is 1255mm so my experience is that their figures are somewhat conservative.

BTW, what size are you/how slack is your bike that your wheelbase is over 1300mm? I thought my Honzo was an oil tanker of likely unparalleled length!

I've considered airing down the fork to put it on the rack, or building a boost hub onto a bmx rim and fitting that and sticking the 29er wheel inside the car.