Another Swingarm brace, with a twist,, under slung caliper

[E.Marquez]

Not that another brace added to a VTR swingarm is groundbreaking... Just thought another thread might get someone motivated to do there own, or an idea of something different.

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

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.


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.


The 2000 CBR900rr uses a much different swing arm and the brace is not really useable for this mod.


With the donor swingarm in hand, the project started by cutting off the brace


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.

[E.Marquez]

Spent some time on the Mil today....

The brake caliper strut mount is done






Milled from 6061Aluminum
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 crouton 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.

[E.Marquez]

Cut the VTR caliper bracket down last night and did a little bit of finish work.




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...

[E.Marquez]

Long past my drinking and partying days, so in the shop I go on this New years eve...

My used VTR swing arm came in today.. so removed the chain guard and chain slider, and fired up the cut off wheel and air sander.

Setting the brace on the swing arm it was clear the casting point center of the top cast section had to go



Chain guard tab and caliper mount tab removed.


Initial fitment looks way off.

[E.Marquez]

Left rear foot initial fitment


Right foot initial fitment


Initial look at where I'll weld the brake caliper strut front mount


I'll start with cleaning up the brace cut ends, removing all weld fill material down to base metal.

Then radius the front mount to fit the general shape of the swing arm...

[E.Marquez]

Spent some time building a simple jig.




As I was shaping the brace to fit, was having a hard time returning it to the same location on the swing arm to check fit.

an hour making a jig saved frustrating and time over all.

[E.Marquez]

Started fitting the brace, but it was getting tiresome,, so I whittled some spool mounts as a distraction.

Rough shaping done, holes bored for the thread to be made.

Will be installing M8x1.25 Stainless steel thread coils.


All taped for thread inserts


Thread inserts installed and locked in place with Locktite #680 retaining compound


Trimming down to final length and facing the back side


All done... when welded in place, the outside face will be just inboard of the swingarm. I'll make the spools tomorrow .

[E.Marquez]

Finished the caliper strut today.

7075 Aluminum bar .750 dia.

Cut and finished to 100mm long


Turned to 15mm on one end tapered to 13mm about mid way to the other end.

15mm end drilled and taped for a M8x1.25 Stainless steel coil thread insert.
13mm end drilled and taped for a M6x1.0 Stainless steel coil thread insert.

8mm three piece high strength rodend on one side that the caliper mount bolt will pass though.
6mm three piece high strength rodend on the other side that will be held in a clevis mount welded to the swing arm.



Need to go pick up a box of M8x1.25 SS nuts as all I had on hand were zinc flange nuts.. But other than that Im about ready to weld it all up.

[E.Marquez]

Old swing arm off

New one on,,, and brace test fit


Test fit caliper strut location, and the placement of the lift mount.

Had to mil some off the lift mounts for better clearance, but still plenty of material left for a strong bond.


Looking at it from a partial rear view


Looking ok, may do some more fitting of the brace today so there is less gap to fill.

Then it all gets welded up tomorrow

[lumpyv]

very impressive mate.

like your wokshop.

[grumpyfrog]

That's me well and truly pissed off now: why was I not blessed with any sort of ability to even think about ideas like that, never mind having any ability to carry it out.
Some very sweet touches going on there. looking forward to seeing it all back together.

[VTRDark]

I like your wokshop.

+1

Nice write up Erik, I especially like the line drawings at the beginning describing the differences between years.

Bike looks fantastic keep up the good work. I think you may even be a first to go with an unslung calliper.

(:-})

[gl_s_r]

I like your wokshop.

+1

Nice write up Erik, I especially like the line drawings at the beginning describing the differences between years.

Bike looks fantastic keep up the good work. I think you may even be a first to go with an unslung calliper.

(:-})

I like all the pictures as well but I'm terrible at it and hardly take any when I do something... It's good for anyone following it and seeing how much goes into it all.

Carl take a search at underslung calipers as there was a whole thread about it

[E.Marquez]

For sure gl_s_r was well before me on the under slung caliber and likely others as well

[VTRDark]

Of course I forgot about your one Mark My memory is getting worse as I get older! And how I missed Rear caliper mounting locations I don't know.

(:-})