Any suggestions how to model a custom chopper frame in Catia?

Its look like you had already done with most of design. ( I mean preparing splines ) You just need rib comment in Part design module to make them pipe frame. Because of some personal reasons i always preffer to use "sweep" command in GSD module rather than "Rib" in PD. Sweep comman providing many more options to handle with complex profiles. Then you can make them solid by "close surface" or " thicken" command. Iam adding my edition for your file. You can check my progress in "ONR_PARTS" body. I just tried to show its logic so steps are simple. You can have much better results with improving it. I wish that helps.

EDIT: Iam not sure whats problem about my data. I think reason is versiron differences. Iam using V5 R21 version of CATIA. Past versions like R20,R18,R17 couldnt open my file. So ive decided to provide more shots to describe my steps for data.

Answered with a tutorial: https://grabcad.com/tutorials/any-suggestions-how-to-model-a-custom-chopper-frame-in-catia

I can't open your file, maybe because of the release. I think the polyline will help you much for a parametric construction.

Greetings

error in opening file . upload another file.

Hey friends I made my Chassis which is modified on royal enfield 350.
Thank you to all of u to support me.
i attached my Catia file

it gives me an error too, but doesn't seem to be about releases...
however, i dont have any other idea, so... what is your release?

Thank you friend ..
i will try ...
and if any problem i will inform u ...
thank u very much..

When I've done this mostly in Proe I create a base model that I then merge by reference into other part files. That way when you change the base model, for example change the rake it will change all other models. The base model is made up of all most 100% lines and curves.

I've attached a picture of my custom frame / bike.