Ex 500 16" to17" conversion

[vintage ex race]

I have a 89 ex 500 that I started racing this past season at Loudon LRRS #442, well I want to convert it over to 17" wheels I already have the wheels , the rear swing arm and all the rear brake parts to convert the rear to disc , The Question is does any one know what I have to do on the front? is it necessary to change the front forks? or can I just flip the 17" wheel so the brake rotor is on the left like it is with the 16" wheels and make up some spacers for a good fit?

[daviid]

you need to make a spacer that will replace the speedo sensor. i believe it is 29 or 30mm