| Dual Disc Conversion.
Thanks to Ben Hiles for this section!! I am going to try and write a bit on how I changed my front end to double disc. First things first. Need, 1x caliper arm 1x caliper 1x disc 6x8mmx110mm bolt (for disc) 1xlower brake line (that makes two all up) 1x steel brake line to caliper (which again makes two all up) 1xdouble banjo fitting (for the two lower brake lines) 1x bigger master cylinder (some say GL goldwing mastercylinder are ok.. I used one off a modern dual disc bike) 1xcb500/550 speedo drive plate (no modification) 2x6mmx30mm bolts and washers 1x8mmx35mm bolt and washer You will also need some patients and some spare 6mm washers for shims, and anything else I may have forgotten now..:P |
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| OK for starters, put the bike on the centre stand, and jack the front off the ground, take the wheel off, remove the axle and the factory disc bolts. Remove the speedo drive, chrome retainer plate, Speedo gearbox drive, and the rubber ‘O’ ring on the hub. Now get your two discs… when you look through them back to back, they will line up, but only on a couple of spots, mark them so when you bolt them together on you hub, they will look the same… when looked though… this is just cosmetic, but I am fussy with stuff like that, and its easier to do now, than when you get it all back together and realize..!!!. Right now that you have made sure they line up, and have marked them, get the 6 110mm long bolts and pass them through disc number one.. this disc is going onto the speedo drive side… if you put them in from the other side the nuts will hit the speedo gear box.. so bolt heads MUST be on the speedo side (fig 1)… now feed the disc over the hub, with the bolts going right through the hub, and put disc number two on, with holes that were marked lined up, and do up the nuts..sorry couldn’t find a torque setting for these bolts |
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| Now put the CB500/550 speedo drive plate in the middle of the second disc, it should be a really neat fit, but it should fit, you wont be able to use you chrome dress ring… no room, next put you speedo gearbox on then refit your axle..if you have forgotten which side the shaft goes into… it insets from the speedo side, once this is done, your front double disc wheel is complete… no the
caliper. Now for starters, remove your front guard. Now you are going to have to refit the wheel for this… and from now on it is a lot of fitting, and removing of the caliper arm to get right. Firstly I fitted the caliper arm, and didn’t check anything…BIG mistake… what happened was, when I squeezed the front brake the caliper wasn’t parallel to the disc, and jammed the whole show up!!!, I mean major drama just to get the caliper mount bolts undone so I could just move the bike… So what you need to do is place the 8mmx35mm bolt and washer into the lower hole on the caliper pivot arm and just nip up…. This will give a good idea of how out of shape the mounts on this fork leg are…. Mine had a gap of more than 20mm between the top mounts on the fork, to the top mount of the pivot arm. Now this is where the patients and trial and error are coming into there own…you need to take the pivot arm off again, and file the lower mount little by little till you can mount the pivot arm parallel to the disc (fig 2), you can use a straight ruler along the side of the pivot arm to check parallel. |
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| now what I did was try and file the lower mount as close as I could to the fork leg, without fowling up the pivot arm, b4 I started shimming the top of the mount (fig 3) |
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| this took some time to get right, because you have to file the pivot mount parallel to the disc
as well, otherwise the top of the pivot arm wont mount to the fork… take your time, you can always take metal off… its bloody hard to put it back on though, and also remember that there is metal filings going into the threads, blow these out b4 screwing a bolt into them… it will destroy the thread, and that’s not a good thing… |