Braced my swingarm
 

Got my swingarm done. Found a nice carbon fiber chainguard for a 900rr that fits. Still not sure what the final finish will be, maybe silver powdercoat, but whatever I choose, won't do it till next winter....:D

looks very nice steve. did you do it or find a local welder? any problems?

I cut the brace off the original 900rr arm,used a plasma cutter.Had a mate do the welding,only cost me $25 and dinner.No problems to speak off,but spent a few hours filing and cleaning up the welds......

Steve the swingarm looks great, but is there that much of an advantage to a braced swingarm? or is it more for looks?

Brace will stiffen the rear,helps with handling.Had Hawkrider (Greg) modify my forks and in the process of upgrading the rear shock,so she should be sweet in the curves..

A braced swingarm on a SuperHawk really has a marginal effect. The pivotless frame has a lot of flex in it by design. That's one of the weak points in the VTR chassis in fact. It's great for the street and makes for a very stable platform. The problem is that once you start to push it hard the flex becomes a limiting factor. A braced swingarm will help, but without something to connect the swingarm pivot to the main frame you aren't going to realize the full potential of it.

Harris in the UK used to offer weld-in frame connectors but they didn't make very many of them. I've been working on a bolt-on design but simply haven't had the time to get it finished.

Do you have a picture of this brace?

i have been blessed.

Jamie go ahead and finish it,hell could make you a few bucks.

I remember an article about the "frame connectors" in a Performance Bikes magazine back in 97 or 98. I doubt you'd be able to find it though. All that I remember is that they were welded in parts that spanned the footpeg bracket and the main frame. It looked cool when finished. You might try contacting Harris??

I believe Spondon did one as well. Here you go:
http://www.spondonownersclub.co.uk/i...esbikes/18.jpg

I think that may be the sexiest thing i have ever seen.

That looks awesome:)

That picture gives me SOOOOO many ideas

Oh no, now we'll never hear your bike run.. you'll just keep improving it. :rolleyes:

Wow !!

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?
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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?
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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.

That brace brings the frame closer to the frame of the RC51 in that area. Welding a brace on there is not a problem for me since I have the equipment for that. Is there any cross bracing that we can not see in the picture?

Roger Ditchfield (Revolution Racing in the UK; built a pretty serious racing VTR for the British Superbike series in the late 90's) suggested welding a brace close to the steering head to stiffen things up. I may get around to that eventually (have my braced arm on now) :)

To reply to an earlier query, bracing the arm requires the use of the 900RR caliper bracket as well as cutting and remplacing the bracket stay on the OEM arm (with the 900RR stay).

Having ditched my stock airbox, Welding a 1/4 aluminium plate between the tubular brace and the rest or the steering head could be an awesome mod, I would avoid welding too close from the bearing aera tough.

i braced my frame like this.

if you look inside frame you will see diagonal braces.

Used a 900rr caliper mount bracket.Cut off the stock bracket channel inside the swingarm and welded in the channel from a 900rr swingarm.See the pics

I would almost guarantee the frame is not heat treated due to the cast pieces that are part of it. Unless in 1997 Honda decided to start using a vacuum casting process, which I seriously doubt, they would not be able to heat treat the finished frame.
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