BSA B50 -500 APG Build

[fredvance]

No part of the tailpiece can be less than 4" from the ground. If you do not attach the belly pan to the tail you are good. If you attach the tail to the belly pan it all has to be 4" or more from the ground.

[Koncretekid]

No part of the tailpiece can be less than 4" from the ground. If you do not attach the belly pan to the tail you are good. If you attach the tail to the belly pan it all has to be 4" or more from the ground.

Thanks,Fred,
That partially answers the question, but I still don't know where the tailpiece officially starts, if I want it to be a continuous straight line.  I could come up at a steeper angle to the 4" level at say the front edge of the tire, then straight back at 4 " from the ground.  Or I could continue the line from that point (4" above the ground at the front of the tire) and end at the tailpiece which would then be something like 6 or 7" above the ground.  Which would be better aerodynamically?  The first would enclose more of the rear wheel and tire, but the second might allow the boundary layer to stay attached longer.  It's probably not all that important, because the boundary layer probably gets unattached when it passes my feet and legs anyway.
Tom

[Graham in Aus]

Tom,
         That's a great looking shape, certainly 'looks' fast!

Without wishing to detract from your eligibilty and technical issues, I am intrigued to know a bit about the technique used to create these mouldings?

Maybe your 'glass man would allow us to share the methods, they look like they've come off a male mould? Did you create the shape around the bike somehow, then wet glass up over the top? You say they are very thin sheets, were these cured flat then bent around the bike?

Hope you don't consider this a thread hijack, and that you could help me with my enquiring mind!  

[Koncretekid]

Graham,
The front is of course, the little Can Am fairing sold by Airtech.  I made a plywood tail end and attached it with two pieces of perforated metal strips and one piece of same material on top to support it (on top of last years tailpiece.)  My fiberglass man, Doug Murphy, made those sheets on a flat surface and draped them over the whole thing.  He also bowed out a couple of sheets at the handlebar ends at my request, and attached that piece with pop rivets, with a small bow beneath.  He will now thicken the sheets up to give it a more rigid shape, and we will start cutting out the necessary parts.  I will then fabricate some metal supports, and hopefully we'll be able to figure out a way to split it horizontally in order to make it easier to remove.  The top part of the front fairing will have to be cut off, as my view plane in thru the headstock.  I will send this cut-off and a template to Gustafsson in Florida to hopefully make me a plastic bubble for the front.  I will, of course, keep everyone posted as to the success and/or problems of this scenario. There are so many others out there that know more than I do, and I appreciate their feedback.
Tom

[Graham in Aus]

Thanks Tom,
                  That's kind of what I had figured out by looking at the pictures, it's interesting that you can even get a bit of a compound curve going, like the additions to the side of your fairing (with the curved former underneath).

I really like this idea, very thin flat sheets, easily curved to suit, then glassed up thicker as required, excellent.

Still a fair bit of finishing to do afterwards, but a lot quicker than making a female mould etc.

Thanks to you (and Doug) for sharing! 

Graham

[Koncretekid]

Doug added 3 layers of glass to my bodywork, and this morning we did some cutting. The foot pegs are moved ahead a foot from before, and it's pretty darn hard to pull my feet up to get them on the pegs.  However, I think that I can tuck them in somewhere in the first mile.  We bumped out the front of the fairing 1-1/2" on each side to about 17" (Can Am fairing was only 14" wide.)  But I'm still not comfortable with my handlebars only 14" apart, to give about 1-1/2" on each side for turning.  So at the cost of a little more time and money, I asked him to bump it out another inch on each side.  Better now than not to be comfortable at 125 mph or more!  The old bikes had cut-outs for the hands and forearms, which of course would allow some steering to get on and off the course. Now we are allowed to enclose the hands and forearms, so it gets pretty tight trying to turn.  We still have to get on and off the course, and negotiate around the pits some.  After he's got that done, we're going to cut down the front and try to get a windscreen made.
Tom

[saltwheels262]

tom,

using a big arc to get off of the course isn't a problem with my bike.
the steering is 15 degrees on either side.

bf

[55chevr]

Bonneville is no problem ... widdddde arc ... paved courses will be an adventure

[saltwheels262]

tom,

using a big arc to get off of the course isn't a problem with my bike.
the steering is 15 degrees on either side.

bf

something I should have added-- you should be at a minimum speed when you head into that 90° or so. otherwise, you have a chance of washing out or going into a 45° if you
straighten up.

works for me at loring and was able to do a 180 at maxton.

bill

[wobblywalrus]

Tom, there are some cafe racer fairings with plexiglas bubbles that fits over 8-inch diameter headlights.  Is an 8 inch wide circular opening enough.  That fairing looks great.  Your method is a lot smarter than mine. 

[Koncretekid]

We cut the fairing today, after bumping out the sides, compare original Can Am fairing, front view, with current view.  Width is now up to 23".  It feels good, being able to turn the handlebars without restriction.  Maybe a bit more frontal area, but hopefully the new shape will still be good. Side view before and after cutting. Hopefully, I'll be able to get someone (trying Gustafsson first) to make me a bubble for the front. In the front view with the rider, you can see what is left of the original Can Am fairing in white.  Not much, but Doug said it was still a huge help to get the compound curves of the front and lower fairing right.  Another problem I have to deal with it ground clearance.  Because of the belly of the new fairing, I am down to 1".  Bumps will be a problem!  New front tire will add 1/4", and I can squeeze another 1/4" at the triple clamps.  That's all!

Tom

[55chevr]

1" is too low ... I found out the hard way ...

Joe

[NSF Ed]

We cut the fairing today, after bumping out the sides, compare original Can Am fairing, front view, with current view.  Width is now up to 23".  It feels good, being able to turn the handlebars without restriction.  Maybe a bit more frontal area, but hopefully the new shape will still be good. Side view before and after cutting. Hopefully, I'll be able to get someone (trying Gustafsson first) to make me a bubble for the front. In the front view with the rider, you can see what is left of the original Can Am fairing in white.  Not much, but Doug said it was still a huge help to get the compound curves of the front and lower fairing right.  Another problem I have to deal with it ground clearance.  Because of the belly of the new fairing, I am down to 1".  Bumps will be a problem!  New front tire will add 1/4", and I can squeeze another 1/4" at the triple clamps.  That's all!

Tom

:roll:Looking good Tom.  The 1.5" clearance worries me though.  We might consider a "drop down" upper tripple clamp to lower the forks a little more.  Can Doug machine a set?
"I love the smell of styrene in the morning"!

[ol38y]

1" is too low ... I found out the hard way ...

Joe

I have a friend who found out sometimes 2" is not enough also.

[Koncretekid]

The easiest way to raise the front end is to get some longer forks.  Honda CX 500, for example; Jim L should have a spare set of these.  Also, Kawasaki 440, and Suzuki GS models have 33mm forks.  The Honda CB360 ones that I'm using are only 27-3/4" long, so I should be able to find some longer ones.  Also, I could just lengthen the damper rods in the ones I have.  Without front brakes, I don't think there is much bending force being applied to this front end. I have a larger rear tire as well which will raise the rear up 3/4" or more.
Tom