Judy 95 steerer, is it knurled or even?

[henrysthreeironbands]

I have a Judy crown with a too short steel steerer and am considering pressing it out and replacing with a longer ti steerer.

Before attacking this it would be good to know if the steerer is knurled because of course then the steerer-crown is likely to be destroyed if I press out the steerer. Does anyone know, and any pics?

Alternatively, if anyone has a cheap billet crown for Judy or Mag I could play with

 

[Lhatch4]

The steerers on on my Mag forks are not knurled. I have a Marzocchi fork with a clamp type crown. The steerer isn't knurled on that one either. I have no idea if Judy steerers are knurled. I'm curious to find out.

 

[henrysthreeironbands]

Which model is it, 10, 20, 21, 30, quadra, and which year?

This one below seems knurled. I was surprised to see it like this, but it doesn't seem as an unreasonable method. Also bare in mind they made 1 million forks per year in top years, and clearly went through several processes over the years (CNC first, then forging) and different forging tools with different shapes, so it is likely they also tried many different processes. Methods could also vary between steerer sizes, as a smaller size means there is more material in the crown to support around the steerer tube.

https://www.ebay.com/itm/305593167338

 

[dyna-ti]

I doubt it is knurled or it would damage the crown on the way in when originally fitted. Plus knurling isnt going to give a tight interference fit

 

[henrysthreeironbands]

But the Mag steerer above is knurled. Of course a knurled steerer surface cuts into the crown, that is the whole point. However, if the tolerances are made correctly, it will not cut more than necessary.

I've made commercial bike parts with knurling and it was the right method in our case.