We all know that the Gen II weighs more than a Gen I FJR, but it looks like Yamaha tried to keep the weight down by going to thinner rear rotors. According to my manual and actual measurements, my 07 has a new rear rotor thickness of 5mm with a wear limit of 4.5mm. Iggy's comparison matrix shows that rear rotors are interchangeable amoung all years. Because my rear rotor is measuring 4.65mm, I checked fleabay to see what used rotors are going for. The ones I'm seeing are listed as coming off Gen I FJR's and the thickness are listed at 6mm and 5.92mm for the 2 that I have dimensions for.
So I'm wondering if Gen I rear rotors are really thicker (anyone actually mic theirs)? Can someone with a Gen I manual please check the specs? As long as the bolt pattern and diameter is the same, I don't see why a thicker rotor wouldn't work because I can't imagine you couldn't push a caliper piston another 1mm into it's bore to fit on a thicker rotor.
Assuming the Gen I rotor is thicker and would work on a Gen II, it would be good to know at replacement time. The only downside would be that it would give all you Gen II haters another reason to bash us for having wimpy rotors.
So I'm wondering if Gen I rear rotors are really thicker (anyone actually mic theirs)? Can someone with a Gen I manual please check the specs? As long as the bolt pattern and diameter is the same, I don't see why a thicker rotor wouldn't work because I can't imagine you couldn't push a caliper piston another 1mm into it's bore to fit on a thicker rotor.
Assuming the Gen I rotor is thicker and would work on a Gen II, it would be good to know at replacement time. The only downside would be that it would give all you Gen II haters another reason to bash us for having wimpy rotors.
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