That's actually the Moriwaki race bike I think. The Harris parts were very similar but I think they reused the stock rearsets.

 

jamie

that is the spondon bike.
the moriwaki had ram air.
im sure it is full of moriwaki parts though

 

This is what I found on a old article that I print in 2000.
This adress at this time was
(www.interactivemotorcycle.com/index/features/s-hawk.htm) I think it dosnt exist anymore.
The article were about the Erion Racing Superhawk:

Bla bla bla... While this "flex-by-design" characteristicmay be useful on the street at quasi-legal speeds, it is anathema on a racetrack. Razor sharp front end feedback is vital, and a flexing chassis that whallows as the rider rolls on the throttle exiting a turn while cranked over is about as welcom as a visit from an IRS auditor. The Superhawk provides too little of the former and too much of the latter. Therefore, one of the first things Erion did was to strip the project race bike down to the bare frame and determine a way to get rid of the built-in flex.

The accomplished their goal in two ways: First they fabricated custom aluminium plates wich were welded to the inside of the open, webbed sastings at the base of the fraim rails. Second, they braced the swingarm by cutting off the top of a CBR900RR swingarm and welding it directly to the Superhawk unit; it just happens to be a perfect match. These modifications yielded an extremely rigid chassis wich would now respond positively and predictably to suspention upgrade. An Ohlins shock and inverted forks were fitted to the chassis , along with Brembo brakes to handle deceleration duty. Bla bla bla...

So it have been done before...
I am planning to do more track day this year with my new baby, so if someone could find more information about those aluminum plate that reduce the flex and mayby built them, I will be the first buyers...

Thanks,

 

Im thinking about doing it to mine, next time I rebuild it. I may make an extra set or two of plates.

Someone on here has their bike done like that, but I forget who.

 

So it's basically a plate that extends down to the swingarm mount to tie it in to the frame?
________
HERBAL HEALTH

 

what im talking about, NO. Its a plate to box in the cast rear portion of the frame. Its hollow if you didnt know, not box tubing like the rest of the frame. Boxing it in makes it much more rigid

 

Oh, from the pic I saw I thought it was a brace going from the frame to the swingarm pivot point.

Hey Steve, did you have to redo the mount for your rear caliper when you did the brace?
________
Piero Taruffi

 

I've been working on a bolt-on design off-and-on for the past year or so. Most folks won't want to weld something in place. Having something like that CNC machined is no sweat and probably would cost less than $100. A bolt-on design would be a tad more expensive but without the need/cost of TIG welding it would actually be more cost effective. The design is not finished yet, mostly because I can't decide if I want to keep the stock rearsets or incorporate provisions for something else (sort of like what's shown in the photo posted above).

 

I guess that the swing arm brace is probably the best bang for the buck, I could question how much stiffness could be gained from the rear castings, since the engine is a frame component and bolted very strongly ahead of that, so improvement yes, but probably very little compared to the weak swingarm.
There's other aera to check for, healthy, tight head bearings, better forks, forks brace, healthy wheels bearings good tires well inflated....... and then and only then, if I'm still bored as hell, I could yank the engine out and weld those castings. Not sure if the frame is heat treated tough, but if I ever rebuild my engine I may consider this.
Just redoing my left side weld may be an improvement, this bike was built Friday at 4 :30 PM or made in Zimbabwe by an 8 year old kid.

Edit : just checked the bike a little and the engine is bolted to the lower frame brace, maybe there is more to gain, kinda hard to eyeball.
I'm gonna try and chain the front and rear wheel to the trees and pull the engine with a pickup truck to measure flex, I'll be right back.