Author Topic: Twin disc caliper modification?  (Read 593 times)

Offline SteveD CB500K0

  • Administrator
  • SOHC Jedi
  • Posts: 3678
  • Ride on the Steel Breeze...
    • View Profile
    • Steve's Blog
Re: Twin disc caliper modification?
« Reply #15 on: February 12, 2020, 12:27:49 PM »
I didn’t even know the cunifer was a thing.

Had to Google it


Sent from my iPhone using Tapatalk
2015 Tiger 800 XRT
1971 CB500K0

Offline sprinta

  • SOHC Member
  • Posts: 179
    • View Profile
Re: Twin disc caliper modification?
« Reply #16 on: February 12, 2020, 02:37:09 PM »
The internal dimension of the brake line inlet on the Caliper is identical to bleed nipple inlet except the port to the piston chamber is approx 0.5 mm larger. As Bryan mentions it is not threaded all the way. The thread is 1.25mm pitch.

Photo of the olive below.



(Attachment Link)

Are you indicating that with the 'olive' removed both sides have the same seat face such that the nipple can be fitted to either side without any further modification?

Offline 71 V12

  • Newbie
  • Posts: 49
    • View Profile
Re: Twin disc caliper modification?
« Reply #17 on: February 12, 2020, 04:38:46 PM »
Hi Andy,

Visually the inlets look the same. The only difference that I can see is the hole at the bottom of the inlet on the brake pipe side is about 0.5mm bigger than the bleed inlet to allow for the olive insert.

Therefore to fit the olive in the bleed inlet that hole would need to careful enlarged. I guess you would want The olive to be a slight interference fit and perhaps a small tab of thread lock to seal it well.

Having said all of this, I really hope that the pipe will seal with right brake tube nut and OP1 flare.

Offline Bryanj

  • SOHC Jedi
  • Posts: 6220
    • View Profile
Re: Twin disc caliper modification?
« Reply #18 on: February 12, 2020, 05:45:41 PM »
Kunifer is way easier to bend, never rusts and seals better as it forms to the shapes better.
The only vehicle i would use original steel on would be a Citroen with hydromatic suspension as they have very odd ends with rubber seals

Offline sprinta

  • SOHC Member
  • Posts: 179
    • View Profile
Re: Twin disc caliper modification?
« Reply #19 on: February 26, 2020, 02:11:34 PM »
I am considering doing a twin disc conversion on my 73 CB750 K2 and currently looking at all the parts I would require to do the modification.

On looking at the caliper whilst it it is straightforward to fit to the RH side they are handed in the sense that the nipple will now be closer to the fork tube and the hydraulic pipe now furthest away as the seats for the nipple and hydraulic pipe are different with the nipple using an inverse cone shape and the pipe a raised cone seat.

On looking at the relevant parts book page, see attached, there is an unnumbered part that looks to be some sort of olive insert above the pipe connection position.

Can anybody advise if this a push in seat that can be removed or if there is a relatively simple process so the nipple and hydraulic can be fitted as a mirror image of the LH side with the hydraulic pipe close to the fork leg?

Removing the 'olive' is fairly straightforward.

The bore of the olive is around 3.2mm dia and as such will take an M4 tap.

After tapping a few threads into the olive it can simply be drawn out with an M4 screw, nut and washers, see attached.

With the olive removed both threaded holes and seats are the same, at least on my caliper. So all that is required is to press the olive into the original nipple bleed hole and the screw the bleed nipple into the original brake pipe position.

Offline 71 V12

  • Newbie
  • Posts: 49
    • View Profile
Re: Twin disc caliper modification?
« Reply #20 on: February 26, 2020, 08:40:57 PM »
Neat job Andy.

Any thoughts on how to insert the olive into its new location?

Cheers,

Kevin

Offline sprinta

  • SOHC Member
  • Posts: 179
    • View Profile
Re: Twin disc caliper modification?
« Reply #21 on: February 27, 2020, 01:32:41 PM »
Neat job Andy.

Any thoughts on how to insert the olive into its new location?

Cheers,

Kevin

Not 100% sure at the moment?

Need to put a couple or so more threads in the hole first to be sure the brake pipe flared end will clamp up and seal against the olive face once fitted.

Andy

Offline sprinta

  • SOHC Member
  • Posts: 179
    • View Profile
Re: Twin disc caliper modification?
« Reply #22 on: February 29, 2020, 11:31:13 AM »
Thread just needed cleaning up.

Using the M4 screw just tapped it in and then screwed in the flared brake pipe to fully seat it.

Offline 71 V12

  • Newbie
  • Posts: 49
    • View Profile
Re: Twin disc caliper modification?
« Reply #23 on: February 29, 2020, 06:48:31 PM »
Simples, well done👍👍👍👍

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal