Exhaust fabricating...?

[rohorn]

I need to fab up a 2-2 exhaust system for my EX500 racer project (stock engine in a...different frame). Is there a good source of tubing bends in/around Denver? Also - can anyone recommend any good/cheap header design software - or should I just stick with the formulas in A. Graham Bell's book?

I'm not expecting to develop a killer system - I'm just hoping to build one that's no worse than stock. But better would be, uh, better. How much muffler do racers need, anyway?

Getting this done should get me one step closer to the track...

[dave.gallant]

No idea on exhaust fabricators, but what frame are you using? I love FrankenBikes.

[JWinter]

Contact Jay Wright at Bare Bones Machine, He built two custom exhausts for my supermonos. He is in Woodland Park his number is 719-687-0431.

Jeff

[rohorn]

I love FrankenBikes.

It's homebuilt - just pulled the tacked frame off the engine last weekend and finish welded it. Still have lots of details left (battery mounts, cooling system mounts, foot controls, bodywork, etc....)

Rolling it up for the tech inspection should be lots of fun - can't wait...

[rohorn]

Jeff,

Hadn't thought of that - thanks!

[JWinter]

Dave, check out this site for some conversion kits for dirtbikes (including a kit for the Ape SXV 550); www.450GP.com

Jeff

[froth]

Alright, Chris Dale:

Looks like the gauntlet has been tossed down. Let's get YOURs on the track.

[Bartman]

It would be a good idea to run it by the shop before the first race just in case you missed something you will have time to fix it. Just give me a heads up and we will check it out.
Bartman

[rohorn]

Bart,

That would be a huge help - I'd rather spend that first weekend racing rather than fixing the mistakes made before I got there.

Forgive my ignorance, but which shop would that be? The TK link is vaguely entertaining, but I'm having a hard time reading it.

[kamper11]

I have a good friend in Englewood who has his own small shop and can fab a killer exhaust. He does hi perf BMW (automotive) stuff and fabbed a custom for my Aprilia. He understands power so it wont just be a couple of pipes that fit... pm me if interested and I will connect you with him.

[Bartman]

Doh forgot to mention which shop, just used to people knowing. Fastermotosports is where you need to bring it for a look over or for the right amount of beer I could be talked into a house call. :lol:
Bartman 303-825-0975

[rohorn]

Kamper,

I'm going to try to make my own - if it is pathetic, that'll be in the Plan B file. Thanks!

An order for a bunch of bends and some tubing is going out tomorrow:
http://www.spdexhaust.com/

Bart,

Cool - thanks! The tires for this project were bought & mounted there.

[dave.gallant]

How about some pics? I would love to see this frame...

[rohorn]

Pics? These are over a year old - with lots of details missing - but they are the newest ones I have.

On the bench:

http://i19.photobucket.com/albums/b1...n/100_0258.jpg

http://i19.photobucket.com/albums/b1.../fitcheck1.jpg

The front suspension uses a hub center steering lower with an upper A-arm. The front and rear suspension, using the stock wheels, is done - no pictures of any of it - yet. It uses a CBR954 shock on the front and rear end. There's a modified rear wheel on hand that'll get a better rear suspension once I get some track time.

The seat should be 15" off the ground (static, with rider on it) and have close to 60 degree lean angle - the engine won't touch the ground.

You said you like Frankenbikes...

[dave.gallant]

I can't wait to see it finished!

[Desmodromico]

Holy crap man, so you plan to race this? You may want to leave a horn on to warn people when you come up the inside on a corner lest they turn in on top of you!

[kamper11]

My friends shop and contact info (i wanted to make sure he was ok with me posting publicly). Not only can he fab exhaust - but he's a master welder and his work is top notch.

Here is Justin's website with Info and contact.
http://www.bbfabrication.info/

Contact phone 303-719-1814

[Bartman]

I have never seen a recumbent motorcycle before, I have ridden a recumbent bicycle and while fun to putter around on I could not see racing one road style. Not to say it could not be done but there are several drawbacks I can think of right now, moving your body weight is a big part of making a bike go fast around a track and I am betting the wheel base will be rather long. Any idea as to what it will weigh and where the center of gravity will be?

[rohorn]

Bart,

It should be very close to 50/50 - with the rider on it. It will weigh around 370 lbs. That's a lot heavier than I'd like, but considering the engine, the skill level of the rider, and how little was spent on it, I can live with that for now. The wheelbase is long, but with the low CG and steep steering geometry(18 degrees), I think it will handle OK.

I built this almost 6 years ago:





I got to spend a morning with it at the Calhan kart track late 2005. It was a little weird cranking it over far enough to drag my butt (around 50 degrees on the left side, 30 degrees on the right - the engine would drag on right handers - oops). Leaning out my inside knee would leave my entire leg just off the track surface - and being that low, it takes very little body movement to make a big difference. It was front heavy and tended to push the front end, but I could push it and recover with little trouble.

The limited lean angle on the right and 40(ish) mph top speed (only so much you can do with an air cooled 40cc piston port 2-stoke) resulted in it getting turned back into a stand-up scooter and sold. But it did make me want to build something similar that is a lot faster. I thought about making a Polini powered version, but it would have cost not much less than the current project.

I've been told by someone familiar with the Gurney Alligator's racetrack behavior that a combination of a long wheelbase and low CG can make the back end "rather excitable" driving out of corners. That's the main problem I'm expecting with the new one, but the next rear suspension should theoretically compensate for that. That next unit is a lot more complicated than the current one - and I need to get some track time first - so that will get done later.

There's a lot of work left to be done before it hits the track - and a lot more work left to do after it gets there. All of which is my idea of fun.

[OUTLAWD]

awesome!

I can't wait to get my own place with a garage so I can start playing