Subframe help/ideas wanted

First off do not laugh too hard at my high tech artwork! I want to build a new subframe if that is the correct terminology. Anyhow the backhalf of the frame. I mono shocked the frame and want to build or purchase a tail/seat like this unit.


In my blueprint(part of it is blue) the larger is stock and the smaller is what I am thinking of doing.
Question 1-How does one address area B after removing that tube?

2- How far down and out does the brace need to be (see red ?)

3- What type of material is used?




THANKS
Wayne

didnt dutch's z1 have a custom rear sub frame of some sort?
Havent seen him on in a while

Wayne, have a look at Arnold's Retro Fighter 2.0 build, he deals with the issues at point B in a very cool way and has some subframe ideas too. Look in the projects section.

Good going,

Alec

wireman is right sander (dutchz)did some real nice subframe work on his bike.



it can be as simple as a triangle,




but the lower support tubes need to be behind your a$$ to properly support you.
if you plan to have a passenger the lower tubes need to be behind the passengers a$$.

the slickest i have seen area "b" capped is by bending tubing to make the radius and then cut a section out of the bent tube and weld it in and blend it out.
like arnold did ,










leon

Thanks guys! Arnolds stuff is killer. I like the way he handled point B. I could maybe do that if I could source the bends. Thanks for the input on butt placement Leon! Going to be a single seater.

I assume triangulation will be strongest if supporting tubes are at 45 degrees or less?
Wayne

the lower tube is in compression,so it is going to be very strong.

i would use 1" .065 wall thickness 4130 chromoly if it were me (because that is what i use on everyting ).
but some nice 1" d.o.m. would be sufficient.

www.shapirosupply.com/index.php?main_pag...45738109aec79fdf8075

i would use the same size tubing top and bottom.

hth,
leon

a lil inspiration .




leon

YOWSA

Nice 750, very well done.

now that is SEXY