| The 600SS uses a wheel with a 20mm front spindle, but its bearings and spacer can be fitted in the later wheels in place of their bearings and spacers that suit the 25mm spindle.
I am fairly certain my 750SS uses the same 4.5" rear wheel, I will check.
And yes the wheels are prone to damage I have a rear with a nice bit of distortion in it. | 
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