And those are the stock sizes.

https://cdn.powersports.honda.com/documentum/MWOM/ml.remawmom.2014_31mjr600_gl1800c_a_valkyrie.pdf

 

I dont see much point in sticking with the stock sized front when there are more and better 120/70R19 options easily available.

180/55R17 rear is plenty available but you could do a 190/55R17 and probably be a bit more accurate on the speedo or even a 200/50R17 if you like the look.

 

I was wondering if our bikes will take an 18” Front Goldwing wheel.

 

Maybe... But I bet there would be some challenges to overcome as the Valkyrie and Goldwing use COMPLETELY different front braking assemblies, I don't think there is really anything substantial even shared between the two.

 

Engine, Frame and rear wheel 🤷‍♂️

Try reading what I wrote again:

the Valkyrie and Goldwing use COMPLETELY different front braking assemblies, I don't think there is really anything substantial even shared between the two.

The whole front wheel braking assembly including how the rotors attach to the wheel, the rotor diameter, the brake calipers, the lack of the whole ADV, is all completely different between the Goldwing and 2014 Valkyrie. So the spacing may or may not align between the two setups left to right, but regardless you would either need to do something to move the brakes in with a Goldwing front wheel on a Valkyrie or have the pads over the edge of the discs.