CHOP CULT HOME
Email Password
Search
  1. #1

    Default Proper rake for extended springer

    Hey guys, Im going to be raking the neck on my 73 swing arm FX frame and just want to post up my calculations to see if Im going about this the right way. The bike is staying a swing arm and Im not stretching it up or out only raking the neck.

    I used the rake trail calculator found here https://www.rbracing-rsr.com/rakeandtrail.html

    Im going to be using a +12 over Harley repop springer made by samwel that has 3* of positive rake in the steering stem.
    Im running a 16 Avon mkII out back and a 21 speed master up front. Below is a picture of my numbers punched into the calculator. I used the distance from the center point of the rear leg rocker pivot bolt to the center of the axel hole in the rocker as my measurement for my triple clamp offset. When I measure from the top of the rear leg to the center of the axel hole in the rocker I got a total length of 39.437 inches. I set the bike up on a jack at the stance I want it to sit at and then I made sure it was level side to side. It has a stock 30* neck, I put an angle finder on the neck and found that it is at 36.8* when sitting the way I want it to sit (slightly lifted look in the front). To my understanding I want the trail number to be between 4 to 6? Using the calculator I found that I would need to rake my neck to 38.2*. Once its on wheels and sitting in the proper stance the neck will be at 45*. If I did everything right then the calculator is saying that Ill end up with 5.51 of trail. Does this sound right? Am I making any sense at all?? Can I even use this calculator for a springer? Any feed back or input would be great. Thanks! Attachment 109420

    EDIT: you cant see shit in the photo so heres my numbers.

    Front tire diameter: 27.2
    Rake: 45*
    Triple clamp offset: 3.66
    Fork length: 39.437
    Triple tree rake: 3*
    Trail= 5.51

  2. #2
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Oct 2012
    Posts
    141

    Default

    Gary from Chopper Builders Handbook can probably help you.

  3. #3
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Dec 2017
    Posts
    3,015

    Default

    Quote Originally Posted by ncmc47 View Post
    Gary from Chopper Builders Handbook can probably help you.
    How To Measure For Springer Forks

    "In order to build a set of Springer Forks that will properly fit your particular frame configuration we need a few measurements. Please don't just guess at these dimensions. They are all critical to the proper design and fabrication of the forks and/or component parts that we will be custom making per your specifications. We want you to have a perfect fit when everything is installed on the bike...

    Click image for larger version. 

Name:	SPRINGER-MEASURE-EXH-1.jpg 
Views:	2 
Size:	54.5 KB 
ID:	109433

    Send us the measurements you've taken and we'll get back to you with a confirmation as to the length of forks needed for your particular bike.

    You can email (Gary) with questions: gww250@yahoo.com

    or call 707-738-1521"

    https://chopperbuildershandbook.com/...r-measure.html

  4. #4
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Dec 2017
    Posts
    3,015

    Default

    Do you already have the springer and front wheel?
    Is there no front end on there now?

    Set the neck height you want with rear wheel on, put the springer against the neck with center of neckpost in middle of frame neck, level wheel to be vertical, measure rake of forks. Then subtract 3 degrees (rake in trees) and rake your neck. done.

  5. #5
    Senior Member

    Content on this page requires a newer version of Adobe Flash Player.

    Get Adobe Flash player


    Join Date
    Dec 2017
    Posts
    3,015

    Default

    neck rake; 32 to 42 degrees:

    Click image for larger version. 

Name:	neck rake 32 to 42, CA, Kawasaki88Trike-07.jpg 
Views:	2 
Size:	131.0 KB 
ID:	109435

  6. #6

    Default

    Ok, after giving Gary a call he helped me out and determine that my thinking isn’t completely crazy haha. Going to cut it up this weekend and go to 38.2*. Thanks for all the help everyone. I’ll post back when it’s in one piece to give an update.

Share This



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Log in

Log in