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Twinpot Brake upgrade on 78 Skunk

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    Originally posted by salty_monk View Post
    The Ninja MC is a 14mm (aka Ninja 250) if you use one or 5/8" (aka bigger ninja, concourse etc) if you use two...
    Does this Vintage Brake chart still make sense? http://www.vintagebrake.com/mastercylinder.htm


    What is the master cylinder ratio for the single disk + 14mm Ninja 250 MC?

    Comment


      I see EBC offers their pro-lite rotors for the CBR900RR. Do aftermarkets fit the GS wheels also?
      The current garage:
      1978 GS750
      1975 GT750M
      1984 CB700SC
      1982 XJ650 Seca Turbo
      1975 RD250 - 350 conversion

      Comment


        Originally posted by jabcb View Post
        Does this Vintage Brake chart still make sense? http://www.vintagebrake.com/mastercylinder.htm


        What is the master cylinder ratio for the single disk + 14mm Ninja 250 MC?
        Without doing a lot of measuring I can't say... but the stock is 5/8" and the stock Kawasaki is 5/8" and both feel ok. The Stock 250 is 14mm (as is the twin piston KLR) and the stock Suzuki single is also 14mm.
        1980 GS1000G - Sold
        1978 GS1000E - Finished!
        1980 GS550E - Fixed & given to a friend
        1983 GS750ES Special - Sold
        2009 KLR 650 - Sold - gone to TX!
        1982 GS1100G - Rebuilt and finished. - Sold
        2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

        www.parasiticsanalytics.com

        TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

        Comment


          Originally posted by The1970's View Post
          I see EBC offers their pro-lite rotors for the CBR900RR. Do aftermarkets fit the GS wheels also?
          They fit as much as the stock ones do... that's to say all of them need drilling / spacing correctly. I have fitted a few sets of EBC
          1980 GS1000G - Sold
          1978 GS1000E - Finished!
          1980 GS550E - Fixed & given to a friend
          1983 GS750ES Special - Sold
          2009 KLR 650 - Sold - gone to TX!
          1982 GS1100G - Rebuilt and finished. - Sold
          2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

          www.parasiticsanalytics.com

          TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

          Comment


            A question about clearances from the caliper bracket to rotor: How does this look? This is with a 40mm bolt on all three fork mount/bracket positions. Is this what you guys are running? In the first pic, I'm concerned about the lower fork mount to caliper bracket bolt shown without a nut. The second pic shows the same lower fork mount bolt without a nut and the caliper bracket bolts.





            rotor clearance.jpg
            Last edited by hannibal; 08-26-2018, 04:02 PM.
            Jordan

            1977 Suzuki GS750 (My first bike)
            2000 Kawasaki ZRX1100
            1973 BMW R75/5

            Comment


              Second pic
              Jordan

              1977 Suzuki GS750 (My first bike)
              2000 Kawasaki ZRX1100
              1973 BMW R75/5

              Comment


                2nd Pic doesn't show but it looks completely normal. After you put a nut on there you should have in the region of 1/8th inch of clearance (3-4mm).

                By the way I wouldn't run a washer under the bolt head if you are using 40mm bolts (same as stock - 40mm bolts, no washer) - use a bit of blue loctite on the thread. We should be able to see the end of the bolt poking through on the back of the caliper in your picture & I can't (then I looked closer & appears that you're using a washer).

                The bracket is steel in any case so it's basically already a giant washer...

                (also looks like your speedo drive is not located right in that first pic or you didn't fit the dust shield yet as I see a gap).

                Cheers,

                Dan
                Last edited by salty_monk; 08-27-2018, 03:01 PM.
                1980 GS1000G - Sold
                1978 GS1000E - Finished!
                1980 GS550E - Fixed & given to a friend
                1983 GS750ES Special - Sold
                2009 KLR 650 - Sold - gone to TX!
                1982 GS1100G - Rebuilt and finished. - Sold
                2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

                www.parasiticsanalytics.com

                TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

                Comment


                  Thanks Dan. Here's the second pic:
                  bracket clearance.jpg

                  You're right. I had a regular washer and lock washer on the two caliper bracket bolts.

                  The lower fork mount has the Kawa bolt which is a bit shorter (36mm or 38mm?). If I use a 40mm bolt with washer and lock washer, I have the same amount of thread sticking out the back as with the plain Kawa bolt. Without a washer, the 40mm sits REALLY close to the buttons on the floating rotor.

                  I feel like I should be using at least a lock washer on all three of these.

                  And yes the speedo drive was just thrown on there. It's upside down and missing the dust shield. I'm checking everything upside down with the new dual disc lower forks bolted to the fender and the wheel sitting on the forks.

                  One more question about the floating rotors. I read that the buttons should spin freely. Mine don't which means they need a good cleaning. Is this a job for PB Blaster or WD40?
                  Jordan

                  1977 Suzuki GS750 (My first bike)
                  2000 Kawasaki ZRX1100
                  1973 BMW R75/5

                  Comment


                    Hmm the Kawi bolts I've had are all the same. Just make sure you have at least 1mm of thread out the back and 3-4mm of clearance between the two & you should be fine.

                    They don't spin until the get hot.. just make sure they are clean

                    I use blue loctite rather than a lock washer.
                    1980 GS1000G - Sold
                    1978 GS1000E - Finished!
                    1980 GS550E - Fixed & given to a friend
                    1983 GS750ES Special - Sold
                    2009 KLR 650 - Sold - gone to TX!
                    1982 GS1100G - Rebuilt and finished. - Sold
                    2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

                    www.parasiticsanalytics.com

                    TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

                    Comment


                      Just wanted to share a pic of my new setup. Single caliper with a Honda Blackbird rotor.

                      20181002_231641.jpg

                      Only problem I ran into was I bought a caliper listed for an ex500 but it was in fact for the 250 so it was a right hand caliper and the bleeder is at the bottom. I got it bled off the bike just to test everything and it is working great. Although I will order the correct one.

                      Does anyone have a template for the area of pad that needs to be chamfered? Otherwise I'm thinking of letting my used pads wear a little so I can make a template that others can follow.

                      Thanks again Dan for putting this kit together. Everything bolted up beautifully

                      Edit: one question I forgot to ask is that the blackbird rotors have arrows on them indicating a direction. Is this important at all? And also should I be using the factory lock rings on the rotor bolts or loctite?
                      Last edited by The1970's; 10-03-2018, 12:38 AM.
                      The current garage:
                      1978 GS750
                      1975 GT750M
                      1984 CB700SC
                      1982 XJ650 Seca Turbo
                      1975 RD250 - 350 conversion

                      Comment


                        What chamfering?
                        1982 Katana 1100, 1997 HD Ultra Classic, 1996 Buell S2T, 2002 BMW K1200RS, 1969 Royal Enfield Interceptor Triton project
                        New project 1979 GS1000S
                        Recently sold 1979 Honda CBX1000

                        Comment


                          Originally posted by johnod View Post
                          What chamfering?
                          When converting a single rotor GS with the single rotor salty_monk kit the brake pads overhang the rotor slightly and require a chamfer to avoid wearing a lip into the pads
                          The current garage:
                          1978 GS750
                          1975 GT750M
                          1984 CB700SC
                          1982 XJ650 Seca Turbo
                          1975 RD250 - 350 conversion

                          Comment


                            NOTE: THIS ONLY APPLIES TO SINGLE SIDED APPLICATION WITH A 310mm BLACKBIRD ROTOR (CBR1100XX)

                            When you line it up with the rotor it's fairly easy to see where the overhang is. Nobody has ever laid up a template though - that's a great idea. Some pics of the pad once done would help too. I don't think I have any good ones.

                            It's approx 3mm-4mm in from the edge from memory.

                            The chamfering stops the rotor from wearing a step/lip into the brake pad over time (1,000's of miles) which could be at risk of jamming up on outside edge of the rotor or breaking off & getting caught between the pads & rotor.

                            It's annoying that the left calipers are harder to source than the right ones! Would be much better for our purposes if the left was used on the Ninja 250! They can provide a good source of parts for an older left caliper though as pistons, bracket etc are the same.
                            1980 GS1000G - Sold
                            1978 GS1000E - Finished!
                            1980 GS550E - Fixed & given to a friend
                            1983 GS750ES Special - Sold
                            2009 KLR 650 - Sold - gone to TX!
                            1982 GS1100G - Rebuilt and finished. - Sold
                            2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

                            www.parasiticsanalytics.com

                            TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

                            Comment


                              Ah, ok thanks, dual caliper here, that's why it didn't sound familiar.
                              1982 Katana 1100, 1997 HD Ultra Classic, 1996 Buell S2T, 2002 BMW K1200RS, 1969 Royal Enfield Interceptor Triton project
                              New project 1979 GS1000S
                              Recently sold 1979 Honda CBX1000

                              Comment


                                Yep, not an issue with the Dual caliper & CBR or GS550 solid rotors.
                                1980 GS1000G - Sold
                                1978 GS1000E - Finished!
                                1980 GS550E - Fixed & given to a friend
                                1983 GS750ES Special - Sold
                                2009 KLR 650 - Sold - gone to TX!
                                1982 GS1100G - Rebuilt and finished. - Sold
                                2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

                                www.parasiticsanalytics.com

                                TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

                                Comment

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