On 10/4/2010 8:43 PM, Snag wrote:
wrote:
On Mon, 4 Oct 2010 16:21:34 -0500,
wrote:

wrote:
On Mon, 4 Oct 2010 08:00:32 -0500,
wrote:

Karl Townsend wrote:
I'd settle for a set of sketches of the geometry ... the budget
on this one is "do it yourself or you can't afford it" .
We've decided to sell her Kawasaki since she's just not all that
hot on leaning into turns , and my budget is whatever I can get
for it . Probably somewhere in the $700-$900 range - which will
buy the materials (I hope !) .

If you're rolling yer own...

Can you start with a shaft drive bike? (That would not be the
Honda 750, its chain drive) Then take the smallest rear wheel
drive car you can find for drive and suspension parts.

I've seen a few people that can just do this. For most it would
be a nightmare to design.

Karl

Well , the thing is that I already have the CB750 , and it's paid
for . Got some ideas for casting a housing for the diff out of
aluminum I have on hand ... start with a lost-foam casting , or
maybe make a wood pattern that I can alter for offset depth to
accomodate the sprocket , since it's off-center . Might be able to
incorporate a single 4-pot caliper on the diff housing , that'd
simplify things a lot too . Ideas , ideas , streaming thru my head
... I had a hard time getting to sleep last night .
You do NOT want a single rear wheel brake on a trike - trust me.

It wouldn't be on a wheel , but on the spider/differential housing .
Still , there is a chance of unequal braking with a normal
differential - but if it's limited slip ...
Likited slip on a short coupled trike with a light front end is
asking for trouble. You DO want to be able to steer it on damp or wet
pavement.

Be safe. Use a brake on each rear wheel (inboard or outboard doesn't
matter) and an open differential.

And it's just this sort of input I was looking for ! Everyone who has
contributed to this thread has given me a perspective on the project that I
might have missed . And I want to thank all of you for your help !!
Got some studying to do . I understand the basic principles of the subject
, now to really dig in and learn some of the finer points . Balsa wood and
straight pins , since I don't have the modeling software I can do some scale
models to verify that my calcs are right ... and to better understand how
changing one thing can affect the entire system .
--
Snag
Inboard brakes lower unsprung weight ...

I'd be looking at ATVs. They have sophisticated front suspensions scaled
correctly to your project, usually of welded tubes that look good. All
the geometry is done. And they have rear differentials and IRS
all-around. So you could get components for either 2(front)-1(Rear) or
1-2 configuration.
I'd keep an eye out on both Craigslist and also any active hunting
forums. You might find a wrecked or locked-up ATV for cheap. You might
also see if there is someone who repairs them, who might have some in
back that he salvages from.
Sounds like you are leaning toward 1-2. I'd prefer the 2-1, but then
I'm a sporty-car kinda guy.

Here's an example. Sounds like he values it around $500

http://dallas.craigslist.org/dal/rvs/1989355251.html

Wow, here's your deal:

http://dallas.craigslist.org/ndf/rvs/1988740364.html


--
I can see November from my front porch