CBF1000

CBF1000 => Brakes and ABS/CBS => Topic started by: StealthAu on 04 June, 2018, 11:31:41 AM

Title: 3 Piston Rear Caliper
Post by: StealthAu on 04 June, 2018, 11:31:41 AM
Greetings CBF1000 gurus,
I don't own a CBF1000, rather a Honda Magna which has become a compilation of various Honda models.
I converted the rear drum brake to disc of a cbr, recently upgrading to a 3 piston caliper off a CBF1000 ABS model.
I'm looking for a little info from those in know.

Firstly, what are the torque specs of the two bleed screws and the banjo bolt?

Second, what is the bleeding proceedure?
I have only come across calipers with two bleed nipples on models with combined braking. Combined braking models have two bleed nipples as well as two banjos. Basically two circuits within one caliper.

Am I meant to bleed this from both nipples? If so, what is the sequence?
Title: Re: 3 Piston Rear Caliper
Post by: alan sh on 04 June, 2018, 03:13:13 PM
The rear brake of a CBF is not combined, so there should only be one bleed nipple - and two pistons, not 3 on the MK1 CBF (and 1 piston on the MK2).

So, I am not sure what you have, but I don't think it's a CBF rear caliper.

Could it be a FRONT caliper you are using?

Alan
Title: Re: 3 Piston Rear Caliper
Post by: richardcbf on 04 June, 2018, 06:30:46 PM
*Originally Posted by StealthAu [+]
.....
Second, what is the bleeding proceedure?
I have only come across calipers with two bleed nipples on models with combined braking. Combined braking models have two bleed nipples as well as two banjos. Basically two circuits within one caliper.

Am I meant to bleed this from both nipples? If so, what is the sequence?
Have you looked in the bleeding manual?!  :007:
https://www.cbf1000.com/index.php/topic,20598.msg247195.html#msg247195

Shortcut... http://bob.ollis-brown.co.uk/manuals/cbf1000/2006-2008-CBF1000-A-16%20HYDRAULIC%20BRAKE.pdf
Title: Re: 3 Piston Rear Caliper
Post by: StealthAu on 04 June, 2018, 10:07:27 PM
*Originally Posted by richardcbf [+]
Have you looked in the bleeding manual?!  :007:
https://www.cbf1000.com/index.php/topic,20598.msg247195.html#msg247195

Shortcut... http://bob.ollis-brown.co.uk/manuals/cbf1000/2006-2008-CBF1000-A-16%20HYDRAULIC%20BRAKE.pdf

Thank you! I was looking everywhere for the service manuals, all the links I found were dead.
Title: Re: 3 Piston Rear Caliper
Post by: StealthAu on 04 June, 2018, 10:08:48 PM
*Originally Posted by alan sh [+]
The rear brake of a CBF is not combined, so there should only be one bleed nipple - and two pistons, not 3 on the MK1 CBF (and 1 piston on the MK2).

So, I am not sure what you have, but I don't think it's a CBF rear caliper.

Could it be a FRONT caliper you are using?

Alan

It is a Mk1 caliper, detailed in the mk1 service manual. Seems there were several varieties with different brakes. 
Title: Re: 3 Piston Rear Caliper
Post by: Whirlwind on 17 August, 2018, 12:26:01 AM
I would always bleed the one farthest away from the master cylinder first (horizontal one) then the vertical one
Title: Re: 3 Piston Rear Caliper
Post by: jm2 on 17 August, 2018, 05:46:34 PM
What?   :005:

One of the front's has two bleeds because they are on different systems (C-ABS).

If the OP really has managed to stick a front caliper on the rear of his magna;
a) he's done well so far,
b) most likely using two out of the three pots anyway and only one bleed nipple will actually work
c) so for the extra effort has now got a 2-pot rear

I think we need pictures ....
Title: Re: 3 Piston Rear Caliper
Post by: Whirlwind on 17 August, 2018, 06:49:03 PM
If he has used a REAR then my reply is right. One banjo bolt, 2 bleed nipples ...
Title: Re: 3 Piston Rear Caliper
Post by: Biffern on 18 August, 2018, 09:59:24 AM
My rear caliper is also a 3 piston, only one banjo and 2 bleed nipples. Recently bought OEM pads and the rear set are for 3 piston  caliper. Still can't get my head round the fact it only has 1 brake line.
Title: Re: 3 Piston Rear Caliper
Post by: StealthAu on 18 August, 2018, 10:48:53 AM
I'm back, worked out how to bleed it. I'm surprised there is so much confusion regarding the brakes given this is the cbf1000 forum.

there were a few variants of this model with different brakes. There was a mk1 model with linked brakes, hade a three piston rear and two three piston fronts.

This linked brake system was vary different from the usual Honda linked brake system, as found on VFR's and CBXX's.
On the CBF, the front brake lever operated the 3 piston front left caliper and two of the pistons on the front right. No effect on the rear at all.
The rear master when applied would operate all three of the rear pistons, there is a pressure valve in the rear system, when the pedal is applied to a point, it would also operate one front left piston.

Thanks for the help from those in the know, I hope this helps clear things up for those unaware of this variant.   
Title: Re: 3 Piston Rear Caliper
Post by: Biffern on 18 August, 2018, 10:54:04 AM
Thanks for the helpful reply.
Title: Re: 3 Piston Rear Caliper
Post by: Shed on 18 August, 2018, 11:56:31 AM
*Originally Posted by StealthAu [+]
I'm surprised there is so much confusion regarding the brakes given this is the cbf1000 forum.

What confusion?!  :mfrlol:

*Originally Posted by StealthAu [+]
there is a pressure valve in the rear system, when the pedal is applied to a point, it would also operate one front left piston.


The proportional control valve actually activates the centre piston in the front right caliper, not the left.

For reference MK1:

CBF1000 - Conventional brake system, two twin pistons at the front, one single piston at the rear.

CBF1000A - Combined ABS system, two triple pistons at the the front, one triple piston at the rear.
Title: Re: 3 Piston Rear Caliper
Post by: StealthAu on 18 August, 2018, 12:07:08 PM
*Originally Posted by Shed [+]
What confusion?!  :mfrlol:


The proportional control valve actually activates the centre piston in the front right caliper, not the left.

For reference MK1:

CBF1000 - Conventional brake system, two twin pistons at the front, one single piston at the rear.

CBF1000A - Combined ABS system, two triple pistons at the the front, one triple piston at the rear.

Yep, it's the front right. Typo/brainfart
Title: Re: 3 Piston Rear Caliper
Post by: jm2 on 18 August, 2018, 12:14:11 PM
*Originally Posted by Whirlwind [+]
If he has used a REAR then my reply is right. One banjo bolt, 2 bleed nipples ...
Then I apologise for casting doubt and being off the ball on this.
A genuine  :431:  from me.


I was actually thinking this wasn't as straight forward as a rear cbf (a) capiler fitted.
I know some very good modifiers but worry somewhat when I hear people messing about with brakes that may not really know what they are swapping.
Title: Re: 3 Piston Rear Caliper
Post by: alan sh on 18 August, 2018, 03:27:52 PM
As far as I know, the front brake has NEVER operated a rear piston. It's only ever been rear-front.

Ala
Title: Re: 3 Piston Rear Caliper
Post by: richardcbf on 18 August, 2018, 06:04:53 PM
*Originally Posted by alan sh [+]
As far as I know, the front brake has NEVER operated a rear piston. It's only ever been rear-front.

Ala
Yeh, not on a CBF1000, but on other Honda motorcycles....

In the dual CBS, the hydraulic pressure generated on operation of the right lever will act on the pistons on both ends of "three-pot" calipers on the left and right of the front. The braking force generated then will move the calipers on the left to generate new hydraulic pressure on the secondary master cylinder.

The hydraulic pressure will act on the pistons on both ends of three-pot calipers through the proportional control valve, PCV, having the function of pressure reduction, to general braking force on the rear wheel. Furthermore, the hydraulic pressure generated by operation of the pedal will act on the piston in the middle of three-pot calipers in the fore and aft. Similarly to the lever brake, the braking force generated on the front calipers on the left will generate hydraulic pressure in the secondary master cylinder, which will act on the pistons on both ends of the rear calipers. As the result, braking force higher than the time of lever operation will be generated on the rear wheel since all three pistons of the calipers are actuated.

Because of these mechanisms, the dual CBS turns out to be CBS also when the lever is operated unlike the case of Combi Brake. In addition to it, distribution characteristics different from the time of operating pedal will be obtained.

https://world.honda.com/motorcycle-technology/brake/

 :028:
Title: Re: 3 Piston Rear Caliper
Post by: StealthAu on 19 August, 2018, 12:15:40 AM
*Originally Posted by jm2 [+]
Then I apologise for casting doubt and being off the ball on this.
A genuine  :431:  from me.


I was actually thinking this wasn't as straight forward as a rear cbf (a) capiler fitted.
I know some very good modifiers but worry somewhat when I hear people messing about with brakes that may not really know what they are swapping.

No one knows everything about any subject and everyone makes mistakes. Don't sweat it.
No need to worry about me, I know what I'm doing. If I knew how to upload pictures to this site I'd show you the bike in question.
I've converted the rear brake from drum to disc, front brake from single to dual disc. I've built a custom fuel tank by welding the bottom half of a Magna tank to the top half of a Valkyrie tank. All done in a profession and safe manner.

Also, just so you know, mounting front calipers to rear brakes is also very doable. I've done this to other bikes and considered it for my Magna. For my Magna it would have been overkill, it was my backup plan if I couldn't find a suitable rear setup to work with my cbr rear wheel. Thankfully, I came across the cbf model and the specs match what I was trying to do.
When my bike had a cbr single piston rear brake, it was rather underwhelming. The 3 piston cbf rear performs perfectly for my application.
Title: Re: 3 Piston Rear Caliper
Post by: alan sh on 19 August, 2018, 01:22:29 PM
Richard,

it is not hydraulic pressure that operates the rear piston from the front, but a lever at the side of the brakes that operates when the front brake comes on and moves a little bit. I had a VFR with this system and, as far as I know, it is how all the dual ABS systems work from Honda.

Alan
Title: Re: 3 Piston Rear Caliper
Post by: richardcbf on 20 August, 2018, 05:34:20 PM
*Originally Posted by richardcbf [+]
Yeh, not on a CBF1000, but on other Honda motorcycles....

In the dual CBS, the hydraulic pressure generated on operation of the right lever will act on the pistons on both ends of "three-pot" calipers on the left and right of the front. The braking force generated then will move the calipers on the left to generate new hydraulic pressure on the secondary master cylinder.

The hydraulic pressure will act on the pistons on both ends of three-pot calipers through the proportional control valve, PCV, having the function of pressure reduction, to general braking force on the rear wheel. Furthermore, the hydraulic pressure generated by operation of the pedal will act on the piston in the middle of three-pot calipers in the fore and aft. Similarly to the lever brake, the braking force generated on the front calipers on the left will generate hydraulic pressure in the secondary master cylinder, which will act on the pistons on both ends of the rear calipers. As the result, braking force higher than the time of lever operation will be generated on the rear wheel since all three pistons of the calipers are actuated.

Because of these mechanisms, the dual CBS turns out to be CBS also when the lever is operated unlike the case of Combi Brake. In addition to it, distribution characteristics different from the time of operating pedal will be obtained.

https://world.honda.com/motorcycle-technology/brake/

 :028:

*Originally Posted by alan sh [+]
Richard,

it is not hydraulic pressure that operates the rear piston from the front, but a lever at the side of the brakes that operates when the front brake comes on and moves a little bit. I had a VFR with this system and, as far as I know, it is how all the dual ABS systems work from Honda.

Alan
Alan, if you mean me, note that what I posted is quoted from Honda's own web site for which I gave the link.
Title: Re: 3 Piston Rear Caliper
Post by: Shed on 20 August, 2018, 07:11:21 PM
*Originally Posted by alan sh [+]
but a lever at the side of the brakes that operates when the front brake comes on and moves a little bit. I had a VFR with this system and, as far as I know, it is how all the dual ABS systems work from Honda.
Alan

 :435:

Is this referring to the secondary master cylinder, with link rod to the left front caliper?
As found on VFR's, and Honda Blackbird's etc? Is that what you're on about?

 :084:

Title: Re: 3 Piston Rear Caliper
Post by: alan sh on 21 August, 2018, 09:24:45 AM
Yes