GT550 forks and swingarm interchange with GS650

[PistonHoles]

Not sure if this goes here but GS 650 dual disc front end slides right in the triple clamps on a GT550 - maybe others. Swiingarm fits too but you have to notch the fender for the caliper torque rod. Rear master cylinder mounting and actuating was a little tricky but just make sure you have freeplay.

[Evans Ward]

Yep but you need either the 1981-83 GS650E or GS650G forks and not the 650 cruiser ones that have the offset front axle. I did this conversion on my GT750. You can also fit larger rotors (many makes and models) and the popular Kawasaki EX500/ Ninja front brake calipers work well with an adapter kit sold on the GS Resources website by member salty monk. You can't use the stock cross braced factory front fender though but the ones from an early GS550/ 750 and GS850 bolt right in. Here's a pic of mine with Honda Valkyrie 296mm front rotors, EX500 dual front calipers, salty monks adapter kit, and a chrome GS850 front fender. A friend of mine used 320mm Honda Blackbird rotors on his. Your rear disc brake is very cool! I didn't go that route and elected to stay with the factory spoked wheels.

[Evans Ward]

More great reference info on this subject:

Comprehensive list of caliper and rotor candidates
I had been putting together a list of all possible candidates for rotors for the Tokico twinpot caliper swap, so I thought I'd share this info that I've gathered from all over the internet. Some of the sources may not be 100% accurate, so check measurements/photos before handing over any cash, but hope this will help out those searching for parts.

A few of the 296mm rotors have a 21.5/22/23mm offset already, but they are almost impossible to find used, where as the 74mm pcd 296mm rotors are readily available for $75 give or take used. If you have luck finding them, I think the 78mm PCD 296's will be the easiest to drill out accurately using my drill press method of aligning with drill bit of existing hole size, clamping down, swapping to ~8mm-ish drill bit.

I have also listed a few 310mm rotors, which are also useable, as the Tokico twinpot calipers' pads are skinnier than the friction surface height of any of these Honda rotors, but with the 310, you will have about 4mm of excess rotor on the outside that is unused. by slightly angling the caliper, you can get a full sweep over the drilled area of the rotors. This all takes custom modifications to the brackets or different custom adapters, or just use a dremel and grind off the edge of the pad that will hang over 1mm on the single disc application. The 78mm PCD 296mm rotors with Salty's kit is by far the most painless setup.

Here is a fairly comprehensive list, please check all info:
Suzuki GS 2-piston caliper dual brake mod parts

MASTER CYLINDER:
must use 5/8" / 16mm dual disc brake master cylinder & lever
CALIPERS:
Notes from EBC FA129 front brake pad fitment + additional)

1988-2007 Kawasaki EX250F Ninja 250R
EX500A 1987-93
EX500D Ninja 500R 1994-04
1987-1993 Kawasaki EX500A
1994-2004 Kawasaki EX500D(?)
1994-1996 Kawasaki EX500 Ninja 500
1997-2009 Kawasaki EX500 Ninja 500R Frt. Right
1994-2006 Kawasaki ZG1000 Concours dual disc
1996-1997 Kawasaki ZL600B Eliminator (95-98?)
1990-1993 Kawasaki ZR550 Zephyr dual disc
1991-1992 Kawasaki ZR750C Zephyr dual disc
1988-1990 Kawasaki ZX1000 Ninja ZX-10 dual disc
1988-1996 Kawasaki ZX600 Ninja 600R dual disc
1987-1990 Kawasaki ZX750F Ninja 750R dual disc

1998 ZX-6E
1993-1995 ZX7
1995-1996 Kawasaki ZX9
1994-2004 Kawasaki ZG1000A Concours (94-06?)
1993-2001 ZX11

1991-1993 Suzuki GSF400 Bandit Front
1991-1993 Suzuki GSX1100G dual disc
1989-1995 Suzuki GS500 Front Right
1990-1993 Suzuki VX800 Front



296mm DUAL ROTORS: (Make sure you get the Non-ABS version rotors)


(*78MM PCD - BUT JUST NEED TO ENLARGE BOLT HOLES)
***MD1014X / XC / CC & VR1014BLK / BLU / RED***
296mm 62.2 center 17.2 offset 78mm PCD
to fit:
98-09 VFR800
99-00 CBR600F4
93-94 CBR900RR Fireblade
08 XL1000 VA8 Varadero (Canada)
97-03 GL1500C/CT Valkyrie (all models)
00-03 GL1500CF/CD Valkyrie touring (all models)
01-17 GL1800/1800A Goldwing (all models)
99-00 CBR600F4 (not F4I)



***OEM only, no EBC aftermarket available, only Chinese or MetalGear.com.au ***
CB1 400 1989-1990 EDIT - CB1's are single 310mm 74pcd 20mm offset
CB400 FOUR 1997-2000 (non-USA only?)
CB400 SUPER BOL D'OR 2005 (non-USA only?)
CB400 SUPER FOUR 2005 (non-USA only?)
CB400SF 2002-2004 (92-97?) (non-USA only?)
CB600F "599" HORNET 1998-1999 (USA & international) (a good used score but not common, 2yrs only, no EBC aftermarket available)
Outer Diameter: 296mm
Inside Diameter: 62mm
Bolt Circle Diameter: 78mm
Bolt Hole Diameter: 6.4mm
Bolts:6
Disc Thickness: 5mm
Total Thickness (width/offset): 23mm (NOTE - THESE ARE SAME HEIGHT/OFFSET AS OUR STOCK GS ROTORS, DO NOT NEED 5mm HUB SPACERS or speedo drive sheetmetal dust cap modifications required on some GS models)
"Arashi" Brand DBS007MB Chinese aftermarket in fancy packaging and cloned Arai helmets logo...


(*REDRILL NEW BOLT PATTERN TO USE THESE 74MM PCD ROTORS)
***EBC # MD1139***
Honda CB600 F/S-Y,1,2,3,4,5,6 HORNET 2000-2006
OD:296MM
ID:58MM
THICKNESS:5MM
NO OF HOLES:6
BOLT PATTERN:74MM
HOLE SIZE:6.4MM
HEIGHT:23.5MM

(*REDRILL NEW BOLT PATTERN TO USE THESE 74MM PCD ROTORS)
***EBC # MD1003X / XC / CC & VR1003BLK / BLU / RED***
296mm 58mm center 17.2mm offset 74mm PCD
94-97 CBR900RR Fireblade
95-98 CBR600RR F3
94-97 VFR-750 (non-ABS only)
98-05 VTR 1000 F Superhawk
88-02 Honda RS250
88-07 Honda RS125 (single disc, right rotor only)


I found this info on the internet. I can't vouch for its accuracy.

‪http://www.thechopperunderground.com/forum/index.ph‬" onclick="window.open(this.href);return false;

Year Model Length OD ID

75-77 GT750 B,A,M 25 35 26

1974 GT750 L 23 35 26

72-73 GT750 J,K 25 35 26

1979 GS750 LN 28 37 28

77-79 GS750 EN,N,E,EC,C,B 23 35 26

79-80 GS550 LT,LN 28 37 28

77-80 GS550 T,ET,E,EN,N,EC,C,B 23 35 26

75-77 GT550 B,A,M 25 35 26

1974 GT550, GT550 L 25 35 26

72-73 GT550 J,K 23 35 26

75-76 RE500 A,B Rotary 23 35 26

76-77 GT500 A,B 25 35 26

68-77 T500.GT500 R,J,K,M 23 34 26

OHIO CAFE RACERS FORK TUBE SIZE CONVERSIONS
35 Honda CB-750F "Super Sport" (75-78
35 Honda CB-750F (79-80)
35 Honda CBX (79-80)
35 Kawasaki KX-80 G1/G2 (86-87)
35 Kawasaki KX-80 L1-L3/N1-N3 (88-90)
35 Kawasaki KE-175D1-D4 (80-83)
35 Kawasaki EX-250E1/E2 "Ninja" (86-87)
35 Kawasaki KE-250B1-B3 (77-79)
35 Kawasaki KZ-550H1/H2 "GP" (82-83)
35 Kawasaki ZX-550A1-A3 "GPz" (84-86)
35 Suzuki RM-80 K/L/M/N/P (89-93)
35 Suzuki RM-80 R/S/T/V/W/X/Y/K1 (94-01)
35 Suzuki RM-100 N/T/X (79-81)
35 Suzuki DR-125 G/H/J (86-88
35 Suzuki DR-125 SER/SES/SET (94-96)
35 Suzuki RM-125 M/A (75-76)
35 Suzuki SP-125 G/H/J (86-88
35 Suzuki DR-200 G/H/J (86-88
35 Suzuki DR-200 SET/SEV/SEW/SEX/SEY/SEK1/SEK2/SK3 (96-03)
35 Suzuki RL-250 L/M "Exacta" (74-75)
35 Suzuki SP-250 Z/D/F (82-83, 85)
35 Suzuki TS-250 1 "Savage" (69)
35 Suzuki TS-250 B/C/N (77-79)
35 Suzuki GN-400 T/XT/XX/TX/TZ (80-82)
35 Suzuki TM-400 K/L/M "Cyclone" (73-75)
35 Suzuki GS-450 LD (83)
35 Suzuki GS-450 LF/LG/LH/LJ (85-88
35 Suzuki GT-500 A/B "Titan" (76-77)
35 Suzuki RE-5M, A
35 Suzuki GS-550 LX/ LZ (81-82)
35 Suzuki GS-550 B/C/EC (77-78
35 Suzuki GS-550 LN/LT (79-80)
35 Suzuki GS-550 LG (86)
35 Suzuki GT-550 J/K "Indy" (72-73)
35 Suzuki GT-550 K (KAYABA)/ L (73-74)
35 Suzuki GR-650 D/XD "Tempter" (83)
35 Suzuki GS-650 EX/EZ(81-82)
35 Suzuki GS-650 GLX/GLZ/GLD(81-83)
35 Suzuki GS-750 B/C/EC (77-78
35 Suzuki GS-750 EX/EZ (81-82)
35 Suzuki GS-750 LT/LX (80-81)
35 Suzuki GS-750 TZ/TD (82-83)
35 Suzuki GT-750 J/K/L/M/A/B "Lemans" (72-77)


35 Yamaha YZ-100 G/H (80-81)
35 Yamaha IT-125 H (81)
35 Yamaha RT-180A/B/C (90-93)
35 Yamaha XT-200 J/K/KC (82-83)
35 Yamaha XT-250 G/H/J/K/KC (80-83)
35 Yamaha TZ-250 C/D/E (76-78
35 Yamaha TZ-250 F (79)
35 Yamaha RZ-350 L/N/NC/NCII (84-85)
35 Yamaha TZ-350 /C/D/E (72-78
35 Yamaha XS-400 J/K "Maxim" (82-83)
35 Yamaha SR-500 E/F/G/H (78-81)
35 Yamaha XS-500 C/D/E (76-78
35 Yamaha XJ-550 RH/RJ/RK "Seca" (81-83)
35 Yamaha XZ-550 RJ/RK "Vision" (82-83)
35 Yamaha XS-650 D/E/F/2F (77-79)
35 Yamaha XS-650 SE/SF/SG/SH/SJ (78-82)
35 Yamaha TX-750/A (73-74)
35 Yamaha XS-750 D (77)

Just completed a twin pot brake and fork upgrade on my 1976 GT750. Salty_monk's adapter kit (painted with POR15 chassis black), EBC CBR900RR 296mm rotors #MD-1014X (centers painted dark gray), ZX600C calipers (painted with POR15 chassis black and rebuilt with Kawasaki parts), EBC semi-sintered pads FA129V, forks from a 1979 GS750E (leg bottoms brushed clean and clear coated), chrome fender from a GS550. Bolts for mounting the adaptor brackets are grade 10.9 zinc plated flange head M10X40mm 1.25 pitch and 2 washers, 2 lock washers, and 2 nuts. Overall the conversion saved a bunch of weight and gave better damping and travel than the stock GT750 setup. This made the front feel better, turn better and STOP similar to my 2011 DL650. Still looks classic with a huge improvement. Thank you Salty_monk for a great adaptor kit.
Note for anyone doing this conversion: the speedo cable needs to be longer, I ordered one for a 1979 GS750E it's 3" longer and should fit the speedo, brake lines need to be custom made.