Longboard rails

I know this has been on topic maybe a thousand times but I decided to make a thread and clarify some questions I have.

So I am working on my third board that is a 9"3 longboard with 50/50 rails.

Gonna mark the apex in the middle of the rail and then make one small mark a little bit above and below that depending on how round I want them to be? Make something around 2"/4" bands on the deck, but what about the bottom? do I make them exactly the same?

I’ve also made a hard edge around the fin on my last board but should I continue with the 50/50 shape all the way? and what would the difference be?


I know some of you don`t like numbers but for me its easier so far. 

Please correct me if Ii got something wrong. 


In my experience 50/50 rails are more like 60/40 rails… In relation to board thickness and how they get mapped out. Due to deck dome/bottom roll , But not always the case.

I dome my bottom and deck first, then mark my rails and blend them together. -

What do you want this thing to do?

From my experience when someone says 50/50 rails they are usually talking a low soft egg rail. But a 50/50 rail could be 3" thick. You can always sit down with a piece of paper and map out your rail bands.

Your hard edge in the tail will release water better than a 50/50 which depending on your end goal could be good or maybe not. Your soft rail will hold into the wave better/go slower/drag (think nose rider) - hard edge will be a better performer. Lots of discussion in the archives. Spend a few days sifting through it and reading.

I’ve spent numerous hours reading the old rail threads, seems like there are many ways to skin a cat. 

I am working on a longboard that my girlfriend can practice cross stepping on. I am surfing wind made swell that is often slow fat and mushy.

Yeh it seems that 50/50 ends up more like 60/40.


How many bottom “bands” do people use? On my last board I was aiming for 60/40 and made 3 rail bands and 2 on the deck side, then made a tuck line on the bottom. 

I have also watched the video where he uses the fred tool but are they used for softer longboard rails as well?



Hi - I have some pics that might help.  Not sure if they still exist on the original threads(?)  The rail contour is of a Frye longboard at mid-board.  The tail is of a Jim Phillips longboard that I’ve always thought represented a nice blend at the tailblock. The rail band photo is from the classic Bill Barnfield post.