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Various reasons , but ultimately it boils down to the total weight ,and what the tires and suspension is rated for .

I looked into this before

RT per the manual is
259kg (570lbs) unladen with fuel at 90%
495kg (1091lbs) Max vehicle weight

Payload ie everything else 236kg (520lbs)

K1600GT
319kg (703lbs)unladen
540kg (1190lbs)Max vehicle

Payload 22kg (487lbs)

Tire size base on Michelin Road pilot 2
Front tires for both are 58W which is good for 236kg at 270km hr
Rear tire RT 73W which is 365 at 270 km hr
Rear tire GT 75W which is 387kg at 270 km hr

According to that say 601 (1324lbs) and 628 (1373lbs)

There seems to be a bit of leeway on the RT , not as much on the GT, and assuming you are doing 270km an hour,say 167 mph


You should look at the rating for a Honda st1300

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I believe the Honda Gold wing is rated for 402 lbs before it gets to its GVWR.

Seems to be a bit of a hot topic in some circles, its interesting to do a google search on it.

For the record though last year on a two week trip camping I actually weighed my side cases and my top cases before and after being filled ,and it is interesting to find out what is considered in the base weight. for the R1200RT.

Maybe its because everything we brought was hiking style, light weight, but I was surprised that the total weight was about 60 lbs ,which is a good thing since the missus and I are not light weights . We exceeded the gvwr but only by about 20 lbs total.I was 260 ,she was 160.


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