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Twin discs on 2008 Streetbob

  • Lozz
    Lozz
    5 years ago
    Is there another set of forklegs & master cylinder that would be a reasonably easy swap & not extremely expensive
  • Ken in Cairns
    Ken in Cairns
    5 years ago
    Lower leg off a twin disc model, maybe a FatBob, master cylinder on the twin disc models are a bigger bore again maybe a FatBob one would fit.
    Cheers Ken 
  • DJP_120ci
    DJP_120ci
    5 years ago
    Is the ‘08 49mm fork tubes? And are the hubs set up for twin disk? I’m not familiar with that year. 
    If it is 49mm and the hub Will accept a second disk it is a relatively easy job. 

    Fatbob fork sliders work but will require machining a slider and modifying the mounts for the front guard. 

    Easiest way to do it is twin disk lowrider parts. 2014 on.

    Cheers 
  • Ratbob
    Ratbob
    5 years ago
    Nice idea Lozz,
    Good thing is both the 08 Street and Fat bobs run 49mm fork tubes, I reckon they'd be the same length but don't know for sure.
    In the OEM parts list the two bikes have different part numbers for the lower legs but I reckon that's because the Fatbob sliders are black.
    As Ken said, the master cylinders differ in that the Street has a 9/16 bore and the Fatbob 11/16 bore for the twin disc but your existing lever has the same part number. There's different part numbers all the way through to the calipers so I'm not sure how much of your existing brake lines you can use, bit of trial and error.
    The two bikes run the same left hand brake caliper assembly so the right side off a Fatbob part will match your existing assembly.

    Does the wheel need to changed or can you attach a rotor to the right side as well?

    I noticed someone posted their conversion on the US HD forum stating that "The only thing that doesn't line up perfectly is the fender tabs on the fatbob slider. But all you have to do is drill a new hole and you've got that handled."

    Post a pic of your results, cheers
  • Ken in Cairns
    Ken in Cairns
    5 years ago
    The add to what the others have said.
    You will probably have to either do custom aftermarket brake lines or change them to OEM twin disc ones as the splitting block has swaged fittings.

    Didn't think of lowrider parts as I don't own one.
    Talk to your local dealer if they are any good and they shouldbe able to help.
    Good luck.
    Cheers Ken 

  • Daggs
    Daggs
    5 years ago
    yes it would be a pretty easy mod to do with the parts mentioned above and I've often thought about doing it. 
    However I've been riding my street bob for 10 years, (most of it quite aggressively) and although I admit they aren't in the league of sports bike brakes, they have never let me down.
  • DJP_120ci
    DJP_120ci
    5 years ago
    It’s easy enough to do, braking performance is improved, and in my opinion twin looks better on the front. 
    I just used the brake line assembly for a non abs fatbob and it all fits nicely. 


    IMG_2403_1.jpg
  • Ratbob
    Ratbob
    5 years ago
    Come on Loopie mate, In addition to the added custom look, safety and performance benefits, if anyone finds standard HD brakes good enough, they ain’t riding hard enough :)
  • Lozz
    Lozz
    5 years ago

    DJP 120, love the look of the setup & sounds like the easiest & most logical way to go. Yep, it does have 49mm legs. Pic of your bike looks great .


    Thanks for all the input & I know the standard disc will stop you ok but every bit helps with all the cockheads out on the road.


    Now to start looking for the bits...... 

  • DJP_120ci
    DJP_120ci
    5 years ago
    Quoting Lozz on 23 Sep 2018 10:10 PM

    DJP 120, love the look of the setup & sounds like the easiest & most logical way to go. Yep, it does have 49mm legs. Pic of your bike looks great .


    Thanks for all the input & I know the standard disc will stop you ok but every bit helps with all the cockheads out on the road.


    Now to start looking for the bits...... 

    Thanks mate, she is a work in progress that’s for sure. 
    I will be building up a complete new set of forks when my Ohlins cartridges arrive, so will have this set just sitting around. 

    Progressive springs, rsd preload adjusters and already machined for twin disc. If your interested send me a direct message. 

    Cheers 
  • Muzza Wa
    Muzza Wa
    5 years ago
    Arlen Ness big brake rotor? They promise 30% increased stopping power!
  • Muzza Wa
    Muzza Wa
    5 years ago
    Oh! Better stay away from them then. Was unaware of that, thanks 
  • Lucky09
    Lucky09
    5 years ago
    Quoting Muzza Wa on 27 Sep 2018 04:31 AM

    Oh! Better stay away from them then. Was unaware of that, thanks 

    Ive fitted the big brake kit to my 09 nightrain with Lyndall pads with no issues at all. 
    Braking is improved, by how much not to sure. 

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