Author Topic: Single disc to dual disc front brake  (Read 1797 times)

Offline Mag1

  • SOHC Member
  • Posts: 163
    • View Profile
Single disc to dual disc front brake
« on: January 15, 2017, 10:51:27 AM »
Looking at making my 750k7 single front disc to dual braking, what works? Basically the same parts for single disc and fix to other side of forks, or is the brake calliper arm different from each side, looked at various conversions others have done and it looks the same set-up. Will a brake system from 550 work?
Honda CB750K7 1977
Yamaha XS750e 1977
Vespa 100 (being restored)

Offline hairygit

  • SOHC Jedi
  • Posts: 2708
    • View Profile
Re: Single disc to dual disc front brake
« Reply #1 on: January 15, 2017, 11:20:59 AM »
No! you will need 750 parts, the 550 has a smaller disc and while the 550 caliper looks the same, it isn't, the bolts that hold the 2 halves of the caliper together are spaced differently, and the actual piston is larger. The arm for a 550 brake wont fit either, it needs to all be 750 parts.
If it's got tits or wheels, it's hassle, if it's got both, RUN!!!

Offline Johnwebley

  • SOHC Jedi
  • Posts: 3252
    • View Profile
Re: Single disc to dual disc front brake
« Reply #2 on: January 15, 2017, 12:46:08 PM »
I did a twin disc on my 500,

  I got a GL1000 mastercylinder from David Silver.,
 also a double length banjo bolt to accept a second pipe on the tree,

 you just have to sort out the speedo drive ,
lifelong motorcycle rider,and fan

Offline Mag1

  • SOHC Member
  • Posts: 163
    • View Profile
Re: Single disc to dual disc front brake
« Reply #3 on: January 15, 2017, 01:09:14 PM »
Thanks, OK 750 parts only, will investigate speedo drive. What mods are required to existing drive unit?. Have already refurbished and fixed cbr600 master cylinder to my single disc and was no problem and fits well. Will see if I can find more info on this. Thanks again
Honda CB750K7 1977
Yamaha XS750e 1977
Vespa 100 (being restored)

Offline kevski

  • SOHC Pro
  • Posts: 508
    • View Profile
Re: Single disc to dual disc front brake
« Reply #4 on: January 15, 2017, 03:12:45 PM »
I done a twin disc on my old K3 500, new master cylinder matching calipers and and mounts, i had to spin the speedo drive up on my lathe to reduce it's thickness so the second disc would go on, hopefully you won't need to do it on the 750.

Offline Mag1

  • SOHC Member
  • Posts: 163
    • View Profile
Re: Single disc to dual disc front brake
« Reply #5 on: January 15, 2017, 06:35:31 PM »
Thanks, will look into this, if to costly will leave till next winter mods once I have had a chance to ride and tweek.
Honda CB750K7 1977
Yamaha XS750e 1977
Vespa 100 (being restored)

Offline Bryanj

  • Grogu
  • *
  • Posts: 10840
    • View Profile
Re: Single disc to dual disc front brake
« Reply #6 on: January 15, 2017, 07:54:36 PM »
This has been discussed many times before and if you search twin disc speedo drive you will get an answer

Offline MarkCR750

  • Professional half wit and member
  • SOHC Master
  • Posts: 1173
    • View Profile
Re: Single disc to dual disc front brake
« Reply #7 on: January 15, 2017, 07:59:14 PM »
Suzuki GT250A (Nostalgia)
1977 K7 CR750 (lookalike, what of I’m not sure)
Ducati 900SS (Soul & Speed)
Ducati M900 Monster (Handling & character)
Thruxton 1200 (suits me)
James Captain 197 (pure adrenaline, i.e. no brakes!)
"Eff yir gitten awvestear yir gooin te farst"
Sir J.Stewart.

Offline Mag1

  • SOHC Member
  • Posts: 163
    • View Profile
Re: Single disc to dual disc front brake
« Reply #8 on: January 15, 2017, 10:13:56 PM »
Honda CB750K7 1977
Yamaha XS750e 1977
Vespa 100 (being restored)

Offline Bryanj

  • Grogu
  • *
  • Posts: 10840
    • View Profile
Re: Single disc to dual disc front brake
« Reply #9 on: January 17, 2017, 04:42:14 PM »
BUT IT IS WRONG, the 500/550 speedo drive does not work as it is exactly same as the 760-------fed up of saying this!!

Offline Johnwebley

  • SOHC Jedi
  • Posts: 3252
    • View Profile
Re: Single disc to dual disc front brake
« Reply #10 on: January 17, 2017, 05:23:40 PM »
when I did my drive,I had to get this,

 http://www.cmsnl.com/products/retainer-gear-box_44641300000/#.WH5SavmLTIU


 this I used on my 500 !! 

 check for 750 !!!
lifelong motorcycle rider,and fan

Offline Mag1

  • SOHC Member
  • Posts: 163
    • View Profile
Re: Single disc to dual disc front brake
« Reply #11 on: January 17, 2017, 05:51:25 PM »
when I did my drive,I had to get this,

 http://www.cmsnl.com/products/retainer-gear-box_44641300000/#.WH5SavmLTIU


 this I used on my 500 !! 

 check for 750 !!!
Many thanks for your help guys, will review what I need to make this conversion work in regards to the speedo drive.
Honda CB750K7 1977
Yamaha XS750e 1977
Vespa 100 (being restored)

Offline El__burro

  • SOHC Expert
  • Posts: 476
    • View Profile
Single disc to dual disc front brake
« Reply #12 on: January 17, 2017, 09:20:40 PM »
Hello,
Here's a link to my older post about the same issue, mind you mine is a K2.
Cb750 dual disk upgrade http://www.sohc.co.uk/index.php?topic=8469
and my little guide about speedo drive cutting.
cb750 vs cb500/550 speedo drive plate http://www.dotheton.com/forum/index.php?topic=66389

I hope it helps.
el__burro
« Last Edit: January 17, 2017, 09:46:28 PM by El__burro »

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal