yea its strong enough if you make it thick enough

here is a step by step
http://www.streetfighters.com.au/forum/topic.asp?TOPIC_ID=5801

 

You can reinforce fiberglass with strips of wood, and use rubber gaskets at all your mounts. You'll be fine, as long as you have a decent grasp of what works and what doesn't.

 

Agreed!:knucks:

 

your subframe should still hold all of the weight and teh glass tail being cosmetic or ar you trying to build a monaque <----------sp way off

 

the subframe will still hold all the weight...

I was going to glass a tail and slip it over the subframe. Then i would place or create a seat to fit on top of this tail, still supported by the subframe beneath.

 

Are you building it off the bike and then mounting it by slipping it over the subframe? I'd be as worried about it cracking during installation if any bending/prying is necessary to fit it.
My stock subframe and many others have a brace that is raised up off the frame and fits under the plastic right between both seats if you need support.

 

I agree with post #3 - - you can surely reinforce the fiberglass with strips of wood. The surfboard I had in the 80's had stringers glassed into it; it was plenty strong. Good luck with your project.

 

race bikes uses foam glued onto the fiberglass

 

The strength is just gonna depend on how you design it. I built a little fiberglass/honeycomb beam in my engineering intro class that was 1.5 inch thick but supported 4500 lbs pushing in the center over a one foot gap.

Are you building the tail and the seat as one piece? If you do that you will have to do what chandler said and glue foam or a cover on there. If you make the seat a separate piece, then you can actually wrap a seat cover around it.

 

Thanks for all the advice. I'm using the stock seat for now until I can figure out how I want to mold my tail.