Twinpot Brake upgrade on 78 Skunk

[Chuck78]

Buy a set for both left & right, but I "THINK" it may work with the 310mm rotor and the bracket salty makes. Not guaranteed by any means though! I mocked it up, as I plan on making my own bracket for a single disc gs550b, and the angle of the bracket needed to be just slightly different on a single disc leg with the 310mm rotor vs dual disc leg with 296mm rotor.

If I had more time & were in town more than 2-1/2 days a week, I'd pull my bracket off my bike & mock it up for you with my spare wheel, 310mm cbr rotor & gs750b fork, but I am struggling to even get my bike tuned properly with the little time off of work that I have left.

The single disc bikes had 295(?)mm rotors and higher caliper mounts. The dual disc bikes had maybe 275mm rotors if I remember correctly. To run a twinpot ninja/gs500 Tokico caliper and 296mm floating rotor, you need the dual disc fork legs with their lower brake mounts.

[Chuck78]

I think I do recall seeing a few GG550's that had smaller rotors, come to think of it. It was a dual disc model. those fork lefs would most likely not work at all unless you found an alternate rotor size that would work, maybe 275mm honda rotors, and the bracket angle might be slightly different again.

the beauty of the 310 single disc or 296 dual disc setup is at the upper caliper bracket mounting bolt remains in the same place, it is just the lower that needs swung out. 310 with the dual disc fork legs does not work so well with bracket fabrication the way I made mine to look factory original, the lower mounting bolt hole overlaps with where the new hole needs to be. making an adapter plate would probably not work like that, but with more work fabricating, it would have been possible to do the brackets as I did mine but it was just too much effort involved, and the 296 setup stops superbly.

[mattfeet]

So the bracket WILL fit, it just may be angled a bit awry? If that's the case, I imagine it'd still be a much better setup than my spongy OEM setup.

-Matt

Any insight?

[althomas101]

Are there any kits available? If so PM me with details I'd like to order a set. Also I was digging a bunch about possible rotors and I came up with this information. It seems that in a 296 rotor size the VFR800 rotor is the best match for the stock GS rotor. Tell me if I'm missing something.

Use http://metalgear.com.au to get specs on a bike.

1980- 1984 GS1000, 77-83 GS750, all years GS850, all years GS1100
(mm)

Outside Diameter 275
Inside Diameter 56
Bolt Hole Circumference 78
Bolt Hole Quantity 6
Bolt Hole Size 8.5
Thickness 5.0
Minimum Thickness 4.5
Offset 21.5

CBR 600 F3 95-98 or CBR900RR 95-97, VTR1000 superhawk 1997-2006
Rotors:

(mm)
Outside Diameter 296
Inside Diameter 58
Bolt Hole Circumference 74
Bolt Hole Quantity 6
Bolt Hole Size 6.5
Thickness 4.0
Minimum Thickness 3.5
Offset 17.0

VFR800 all versions 4th,5th,and 6th gens, 99-00 CBR600F4, 1997-2010 or GL 1500 Valkyrie 1997-2003
(mm)

Outside Diameter 296
Inside Diameter 62
Bolt Hole Circumference 78
Bolt Hole Quantity 6
Bolt Hole Size 6.5
Thickness 4.5
Minimum Thickness 3.5
Offset 17.5

CBR1100XX 1999-2008 Probably best fit but would require custom brackets due to 310MM diameter.
(mm)

Outside Diameter 310
Inside Diameter 62
Bolt Hole Circumference 78
Bolt Hole Quantity 6
Bolt Hole Size 6.5
Thickness 5.0
Minimum Thickness 4.5
Offset 18.5

EBC rotor specs:
MD1003 296mm 58mm center 17.2mm offset 74mm PCD
95-98 CBR600RR F3
94-97 VFR-750
94-97 CBR900RR Fireblade
98-05 VTR 1000

MD1014 296mm 62.2 center 17.2 offset 78mm PCD
99-00 CBR600RR F4
98-05 VFR-800
93-94 CBR900RR
97-03 GL1500
01-08 GL1800

Calipers and Master cylinder from 88-96 zx 600 r
KAWASAKI
ZX 600 Ninja R C1,C10,C1-C9

They are the Calipers without writing on them and the bracket underneath.

EBC brake pad FA129HH
Fits the following bikes (caliper interchange??)
1997-2009 Kawasaki EX500 Ninja 500R, Application: Front
1988-2007 Kawasaki EX250F Ninja 250R, Application: Front
1994-2006 Kawasaki ZG1000 Concours, Application: Front, Fitment Notes: 2x Required.
1996-1997 Kawasaki ZL600 Eliminator, Application: Front
1988-1996 Kawasaki ZX600 Ninja 600R, Application: Front, Fitment Notes: 2x Required.
1988-1996 Kawasaki ZX600 Ninja 600R, Application: Rear
1994-1996 Kawasaki EX500 Ninja 500, Application: Front
1992-1995 Kawasaki ZR1100, Application: Rear
1989-1995 Suzuki GS500, Application: Front
1987-1993 Kawasaki EX500, Application: Front
1990-1993 Kawasaki ZX600 Ninja ZX-6, Application: Rear
1990-1993 Kawasaki ZX1100 Ninja ZX-11, Application: Rear
1990-1993 Kawasaki ZR550 Zephyr, Application: Front, Fitment Notes: 2x Required.
1991-1993 Kawasaki ZR750C Zephyr, Application: Front, Fitment Notes: 2x Required.
1991-1993 Kawasaki ZR750C Zephyr, Application: Rear
1990-1993 Suzuki VX800, Application: Front
1991-1993 Suzuki GSX1100G, Application: Front, Fitment Notes: 2x Required.
1991-1993 Suzuki GSF400 Bandit, Application: Front
1988-1990 Kawasaki ZX1000 Ninja ZX-10, Application: Front, Fitment Notes: 2x Required.
1988-1990 Kawasaki ZX1000

[salty_monk]

Nope, will likely work fine but you'll probably still need a spacer behind it as the offset is not enough.

I used the CBR rotors just because that was the info I had available at the time. I bought about 3 different sets on EBay until I got to where I got... then I stopped. There may be other different rotors that will work as well.

It seems like demand is picking up again just as I run out of parts. I'll have to get some more cut & it will take 2-3 weeks.

[althomas101]

Ok Great, I'll look for a post saying you have some then. Thanks.

[mattfeet]

Ok, I'm going to do this over the winter and will be using new fork legs with dual caliper mounts. I have a 79 base model gs750. Which bikes would be my best option for dual mount fork legs? Is just about any Suzuki GS model compatible? Thanks.

Matt

[tkent02]

Ok, I'm going to do this over the winter and will be using new fork legs with dual caliper mounts. I have a 79 base model gs750. Which bikes would be my best option for dual mount fork legs? Is just about any Suzuki GS model compatible? Thanks.

Matt

I have an extra set of forks from a dual brake 750.

[mattfeet]

Message me a price shipped to 45236, please!

[Brodie]

Are there any back in stock Salty?

[Govee]

Salty,
I am also looking for a set. Will keep checking for your restock.

[salty_monk]

I got a quote on having some cut but the price has gone up quite dramatically since last time... (more than 50%).

Give me a bit of time to see if I can work something else out. I might have to go overseas for them again

[mattfeet]

Question: Do I need a new wheel or can I just affix a second rotor to my OEM '79 single-sided-rotor wheel?

[Govee]

Most just have a cover on the side with no rotor. Behind the cover it is drilled for a rotor. You just need to pull the wheel and look(my 77 was this way). I'm not sure if one of the parts sites has a picture to show that detail.

[salty_monk]

Question: Do I need a new wheel or can I just affix a second rotor to my OEM '79 single-sided-rotor wheel?

Pull the plastic cover. 80% of the time it will just bolt on, 20% of the time you need to run a tap down the holes to extend the length of the thread.
I suspect Suzuki use those holes to mount it to some kind of Jig at the factory so they had to have some thread cut there but saved some time (time = cost) by not cutting it to full depth.

Either way you can certainly use that wheel. Several people have done so.