Inspired by a post on instagram by fpgeeks (http://instagram.com...vwT/?modal=true) about fitting a Nikko G nib on a TWSBI 540, I decided to try it out with my TWSBI 580.
Here are the steps:
1) procure Nikko G nibs
Easy enough, just ordered them on ebay and received them in about a week time.
2) fitting the nib on the TWSBI
Nikko G nibs are not designed for fountain pens. So, in its origina shape, it will not fit the TWSBI 580.
In order to be able to mount it, it is necessary to make the nib shorter and thinner.
The picture below (from left to right) shows the original nib, the nib shortened and finally thinned (by grinding).
Each square in the background has sides 5 mm long (for reference).
Shortening the nib is quickly done with a file.
What takes a lot of time and patience is the thinning.
However, if you persevere, results are very satisfactory as shown below:
Once you manage to fit the Nikko G nib on the TWSBI you have a superflex pen.
Railroading is not an issue (unless you want to write real fast) and it is quite enjoyable to use.