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750 Twin Disc....should I?

Discussion in 'Supersport (1974-2007)' started by oldandslow, Jan 8, 2020.

  1. Hi all,
    I have a single disc 750ss and was wondering if it was worth getting a twin disc set-up? I have seen various bikes bikes being broken with twin discs, so would that be an option? Would I need a different front wheel? To be honest the bike is not raced or thrashed, so it would be more of an aesthetics (vanity!) upgrade.

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  2. I would! Its fun to change and meddle and mod - especially since its miserble riding weather...
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  3. it would be straight forward if you wanted to, same wheel and you have the redundant fork fixing as you know. You can even use a caliper and disc from a Cagiva Mito if a good set comes up. Master cylinder might be the biggest outlay.
  4. IME well worth it for the initial bite that a single disc can’t match on a bike of this weight. One day it could give you the extra space between close shave and hospital food.
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  5. That bike looks amazing but is crying out for a second disc, JDI :)
  6. Go for it - will look well cool :upyeah:
  7. do it.
    Your front wheel just has a blanking plate on the disc mounting face.
    You'd need the caliper, so I'd look to not just Supersport but monster and Aprilia stuff - you're looking for the 40mm mounting and it was common across all the Italian stuff of the time.

    I think your master cylinder is a PS13, which was common across all the supersport range a the time, so all you'd need is the brake lines, banjo bolt and the right hand caliper. :)
  8. and a disc :). Not sure if you saw my earlier post Sev, I’ve done it a couple of times using Cagiva Mito even, same caliper, same disc and really lucky that the standard Mito chose the right-hand fork leg. .
    Interesting about the PS 13, my memory is shot but had a feeling the bore or stroke was different for two slaves instead of one?
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  9. oh yes and a disk!
    Thanks Chris!
    Top tip about the mito caliper :)

    Re master cylinder - I'm talking shit, its a PS16 on the brakes not 13, that's the clutch master - my mistake!
    Common across 900ss / 900M and the 916 family.

    if you're no fussed about period correct the 18mm radial that came shortly after works really nicely on these calipers.
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  10. KTM caliper and master could be an option too........I can't recall which model, sorry.

    But new KTM parts were about half the cost of Ducati.
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  11. Hospital food can be very good! The Vale Hospital in Dursley (where I was a 'guest' for some weeks!) uses Apetito https://www.apetito.co.uk. It's very good!
  12. KTM Dukes of the era had similar I think. Better with a later remote reservoir master imo
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  13. Thanks everyone! I'm on the case and hunting fleabay.....
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  14. Don't I also need a right side fork?
  15. no, as said, the little cover will reveal the presently redundant caliper fixing on the R/H fork leg.
    • Agree Agree x 2
  16. This one. 5023B829-4560-41EA-B673-B5666E006D52.png
  17. The 750SS single disc brake master cylinder is a PS13.
    The 900SS twin disc brake master cylinder is a PS15.

    Bore diameter 0.512" and 0.59" respectively.

    As the calipers and discs on the twin disc set-up of both the 750 and 900 are the same; the applied logic is that the OP needs a PS15 master cylinder.
  18. Those lovely white wheels will be a lot harder to clean with a disc on the right... just a thought. Personally I would do 4 pad caliper & master cyl upgrade, may give the same braking with less mass. I know you stated this would be an asthetic upgeade.
  19. And it is crucial that you change the master cylinder, back in the day people used to mod CB750 SOHC’s and then complain that the mod was useless, it’s because they failed to change the master cylinder, I did the mod on mine and used a Fireblade master cylinder, the result?, I can chirp the front tyre at 30!.
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