Swingarm brace install + Underslung caliper mount
 

So another swing arm brace install thread.. WHY?...Why not the internet is free :D

Bike is a 1998 (built Jun 1997) VTR1000F
Donor swing arm is a 94 Honda CBR 900rr
I choose the early year (pre 1998) 900rr because I wanted the brace with the box style front leg. I believe it makes a more stable, better looking swap, then the twin leg version.
https://www.superhawkforum.com/forum...1&d=1388242325

The 1998-1999 CBR 900 rr used the twin leg brace.. and I've seen it work out ok, but the sculpted part needed for clearance near the shock, just never looked right to me.. cept one, and that rider boxed in the two legs with sheet aluminum once they were welded.
https://www.superhawkforum.com/forum...1&d=1388242354

The 2000 CBR900rr uses a much different swing arm and the brace is not really useable for this mod.
https://www.superhawkforum.com/forum...1&d=1388242392

With the donor swingarm in hand, the project started by cutting off the brace
https://www.superhawkforum.com/forum...1&d=1388239744

The OEM chain guard tabs were already cut off, so I will just clean up that work and fit a huger chain guard combo.. it does keep chain lube somewhat contained.

As I will be building a under-slung rear brake caliper mount for this MOD, I do not need the 900rr caliper bracket, or the bracket stop from the swing arm.

I will be machining off the OEM caliper bracket stop from the VTR arm as it will no longer be used .

Next step is machining up a caliper bracket strut mount to be welded to the swingarm.

I have ordered materials for the strut, so waiting on those to arrive.

Fitting the brace to the VTR swingarm.. well waiting for that package from the guy in brown....(UPS) on Monday as well.

I'll keep this thread going with updates as I work things out.

I don't believe the line drawing above for the 98-99 is accurate. The twin spar versions I've seen (in pics on-line) have the rear side of the spars enclosed. Are there variations of this design, anyone? I agree with the OP that the full box version makes for a cleaner finished install, but I like the twin spar look better. So, I'm torn, but will probably attemp a mod using the later year version 900rr brace. My idea is too cut the backside of the front spars down to allow a smooth blend with the shock cutout on the SH arm at the front of the spar. This would lower the front of the brace a little, but I don't think that would present any problems.

Erik, are you going to add tabs for swingarm spools?

While it would not surprise me if the lineart is wrong,, it is directly from Mother Honda's OEM parts pages. (I just cut them from the whole pic and removed the other parts of the image)

And yes, I've seen the 99's with the back of the two front legs enclosed.. but others with just the two legs or at least looked that way in the pics I viewed... in any case, I wanted the single boxed front leg, so picked up one of those.
https://www.superhawkforum.com/forum...1&d=1388253379


What I did find is a lot of the ebay ads do not correctly identify the year of the swing arm, with many ads showing fitment from 1997 to 2000. :banghead: .. May be that they all will physically fit, but they are clearly not all the same.

Yes I'll will be welding on tabs for spools :D

Looking forward to this.

Keep us posted!

The boxed braced is also smaller and weeker that's why the other is used mostly .
I have had both braces side by side and the boxed is noticeably smaller .

Just curious, but why the under slung rear brake?

Define weaker? In what axis? weaker at what?

and smaller in what, material cross section? sq mm of contact surface one design to another? sq mm of surface area the boxed base spans compared to the other twin foot?
And then we have the fact the twin foot version is only partially welded to the swing arm (though, that is on the 900rr, a MOD'er could fully weld it on the VTR swingarm)

Have you seen how many of the twin foot braces are mounted? cutting away much of the footing surface of the right foot base to clear the shock? Some have cut most of the leading part of both twin foot base for fitment.

How did you determine one was "weaker" than the other? destructive testing? Computer aided software failure modeling?



Or was it a Mark I calibrated eye :D

Not a flame for your opinion.. just really wanting to know how you came to your opinion.

Thanks

To be different

To move weight lower and forward

To not have to source a 900RR caliper bracket.

To be different.
:D

https://www.superhawkforum.com/forum...1&d=1388285360

Anyone have this version 900rr brace and can measure this?

Better if you can get three measurements for me.. the one depicted above, if you have cut the brace off already, the material thickness (cross section), and the depth of the foot front to rear.

Thanks

In my estimate any brace is an improvement.

This opinion is not based on fact ,but more on feel having recently used the box brace on my bike it just feels better and more settled on the road.

I also believe that the hawks have a certain amount of flex built into them that does nothing to help the bike when you fettle and improve the suspension and then combine that with the latest tyres that are designed for bikes with stiff chassis dynamics that don't flex like the hawk does.

Thats why I think that any brace will help the Hawk to feel taughter, especialy on undulating surfaces.

Just my 2 cents worth and a very interesting thread.

Please keep us informed of your thoughts and progress.

Sorry I didn't take measurements . The weeker brace was lighter thiner material and had more flex .
If I get time later I will measure the brace requested above

This is the brace that I have. For what it's worth it was listed by the seller as a '97. As you stated, the years are miss identified or there were productions changes during a model year.
Anyway, I will get that measurement for later today.

Please get the depth where it contacts the swingarm, too. Can you post some pictures of your brace mod? Especially the area around this front spar?

Just to confuse the issue here is a pic of my boxed brace.

As you can see it fills the space provided and still had to be relieved for the rear shock so that there was no interference.


Some folks cut 10mm of the boxed section where it mounts, I didn't do that and it all fitted up O.K.
http://i1000.photobucket.com/albums/...ps18af0607.jpg

From the rear.

Attachment 23061


And the top.


Attachment 23062


As you can see not much room to work with.


Am extremely interested in how the non box type brace mounts and what if any clearance issues there are with the rear shock!


I believe that the brace I used was from a 93-94 900RR but I could of been misinformed.


As I have a brace now I am more interested in the underslung caliper and am looking forward to seeing how this is achieved as I am not happy with the way my top mounted caliper looks and performs.


The Blade caliper bracket is big and ugly!! And in my opinion looks out of place.


http://i1000.photobucket.com/albums/...psnftl8caj.jpg


http://i1000.photobucket.com/albums/...ps0idn01ry.jpg

Kenmoore, your install is what i plan on doing.

Not planning on cutting the front leg box.. but was going to weld in the rear legs, and the sides and back of the front leg... as well as the left portion of the front box, then use a soft faced dead blow hammer to form the right front part of the box to conform to the shock relief area of the swing arm...then complete the weld.

How was yours done?

Just like yours , I cut the brace of the 900RR swing arm very carefully as I still wanted to keep the taper on the rear of the brace unlike some others I have seen that have been cut square to finish it off.

I didn't shorten the front box like some others have done and like you I used a soft mallet to relieve the front box.


I also thought about enclosing the brace to swing arm but didn't.


I now rate this mod as No 1 followed closely by the lightened flywheel.


Both mods transform the bike immensley.

Brake caliper strut mount
 

Spent some time on the Mil today....

The brake caliper strut mount is done
https://www.superhawkforum.com/forum...1&d=1388355918

https://www.superhawkforum.com/forum...1&d=1388355925

https://www.superhawkforum.com/forum...1&d=1388355932

Milled from 7075 Aluminum
I decided on a captive mount for the Spherical rod end, vice single sided.. Took longer to make, but will provide more strength.

Teflon lined three piece FK Rod end specs at more than 10,027 ftlb Static load... if this application needs more than that... the mount is going to get ripped off the swing arm...:shock:

The strut rod will be steel tube with tube ends weld in or 7075 Aluminum round bar... have not yet decided.

Man, That looks cool!!!

Wish I had a lathe and your talent.

I am restricted by a basic workshop and engineering companies that charge $$$$ like a wounded bull.

Cut the VTR caliper bracket down last night and did a little bit of finish work.
https://www.superhawkforum.com/forum...1&d=1388417820

https://www.superhawkforum.com/forum...1&d=1388417824

https://www.superhawkforum.com/forum...1&d=1388417829

Realized doing it this way, besides having to remove the caliper to bleed, it will require a new brake line. Another $50 to the mod...

If Im spending another $50..... perhaps scrap this plan and go with a proper caliper to start with...

Thinking> Garage > 3rd beer = Bad idea :shock:

Fresh at it this morning :D and after some research... I think a rather common GSX1300R rear caliper and bracket may be a better option.

Buy in will be $60 or so, but I can re use the SS line I already have saving a bit.
The Hayabusa rear axle is 25mm dia, vs our 20mm.. but that is just making a simple bushing to correct. If the alignment of the Busa caliper and bracket is not good for the VTR, I can fix that by milling the Busa bracket, and or building a spacer as part of the bushing to get proper alignment.

The last concern is the distance from axle center to caliper pad swept surface area..
The Busa uses a 240mm disk
The VTR a 220mm disk
So 10mm difference in radius

I think this last point is pretty big, and makes the GSX1300 caliper bracket unusable... unless I buy a 240mm disk.... which adds cost and rotating mass I don't want.. Worse is I just bought a brand new 220mm Galfer wave rotor for the VTR...

Thoughts?

I wonder if there's any way to get a Busa disc to fit?

Or if you can get VTR pads on the Busa caliper and locate it in a way that the radius matches....

Can you find an under slung caliper that's a bolt-on for the VTR bracket? Seems like a longshot, but...

Finding a 240mm disc that fits the VTR wheel is not hard.. heck I could even cut down a larger one if needed and all i could find to fit the wheel..

It's just another part, more cost. Which I would like to avoid.

Hmmmm, perhaps an off set bushing for the busa bracket.

I could bore the 20mm hole in the 25mm bushing off set...that could account for about 4mm. Leaving me 6mm difference :evillaugh:

Have not yet... and truly.. Im about ready to just get a caliper designed for under the swing arm, and machine up a bracket from scratch...

Crap load of work on a limited capacity manual mil.... and the material would be pricey ... plus one slip of a tool... wrong turn of a carriage hand wheel..and you turn a $$ Al billet into scrap

Saw this on another forum.

Yes the caliper bread nipple is upside down so removal for bleeding.


Sure looks neat though!
http://i1000.photobucket.com/albums/...ps0dwo5xqf.jpg

If I use the VTR parts, that is what mine will look like

That looks pretty neat, except the brake line I would run it under the arm and up behind the rear set

Now Erik has to re-make his caliper strut mount with an integrated brake line hold-down.

Hey, if using the VTR caliper and modified bracket, couldn't you just disconnect the strut and rotate the assembly upright to bleed the rear?

I don't know about you guys but when I do mods I get impatient and just want to get it done.

In this case I found it easy to follow the tried and proven method of using the 900RR caliper bracket but I don't like the look of it.


The effort required to undersling the caliper is worth it in my opinion as it gives the bike a totally different personalised look.


Of course cost is a consideration, and as I still wanted to ride my bike I had to purchase 2 used swingarms and a caliper bracket, then weld and paint, as well as buy a hugger.


My all up cost was approx $450- Oz and then there was my time as well.


Looking forward to the finished item


God knows what all this would cost if you got a custom builder to do it!!!