So, the swap itself was fairly straight forward.
To fit the vfr400 nc30 axle in the nc24 swing arm requires the use of nc30 roller bearing .
The sealed bearings in the hub fit the nc30 axle without modding.
You'll beed a 10mm spacer between the spocket carrier and the hub as the nc24 hub is slightly narrower than the nc30 item.
To fit the swing arm in the frame you need to remove 12mm from the spacer on the right hand side inside the frame. You'll also need to use a 25mm bush inside the roller bearings on the left side of the swing arm as the nc24 uses a different pivot to the nsr. And you'll need the bearing spacer from the nsr swingarm between the to sides of the nc24 swingarm on the pivot bolt.
The nc24 uses different shock linkage arrangement but the use of mc28 linkage(from morriwaki man) sorts this. You can use the mc18 dogbone link, but if you can get the mc28 one , it's shorter and gives a nice increase in ride hight.
I had a cbr600 shock on at first but as it's taller it causes the swingarm to foul the left exhaust.
One final thing you need to space the rearsets out about 10mm as the bolt from the footpeg touches the swing arm without them.
Just stick it all in and bobs your uncle.
To get the correct chain line turn the front sprocket over.
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it wouldn't be fun if it was easy!