Radial calipers & M/Cyl on REX
- laidback
- VIP MEMBER
- Posts: 3307
- Joined: Mon Mar 02, 2009 4:55 pm
- Bike: ZRX
- State: New South Wales
- Location: Wagga Wagga, NSW
Re: Radial calipers on REX
ZX9 F1/F2...
Roady - ZRX1200R
Tracky - ZX9R F1 Team Jerry Atric
I've reached the age where 'happy hour' is a nap.
Tracky - ZX9R F1 Team Jerry Atric
I've reached the age where 'happy hour' is a nap.
- Wattie
- VIP MEMBER
- Posts: 10041
- Joined: Mon Oct 31, 2005 12:23 pm
- Bike: ZX10R
- State: New South Wales
- Location: Bligh Park
Re: Radial calipers on REX
he's talking about the radial nissins.laidback1952 wrote:ZX9 F1/F2...

Wattie #55
ZX10R "The Crim"
ZX10R "Gumby"
Proudly Supported by Allfixed Automotive 9634 1455
sam & srt, survived
RGM, left a message
ZX10R "The Crim"
ZX10R "Gumby"
Proudly Supported by Allfixed Automotive 9634 1455
sam & srt, survived
RGM, left a message
- Gosling1
- Team Donut
- Posts: 13826
- Joined: Mon Jun 20, 2005 9:30 pm
- Bike: ZX2R
- State: New South Wales
- Location: Anarchy Road
- Contact:
Re: Radial calipers on REX
I reckon HH's are the greatest brake pad known to mankind.TopCat wrote:...If I was to change anything it would be to fit EBC HH pads - is there much diff these days between stock sintered pads and EBC HHs....


I'll check that link out and see what sort of gobblydook they speak....and what a lot of interesting gobblygook they spoke of.
In true yank fashion, one know-it-all HIllbilly just rubbishes anyone who dares to disagree with his opinion about hydraulic theory.....and the one bloke who did actually know what he was talking about, gave up in disgust about 1/2 way through the thread. He was the bloke arguing against the use of a smaller-piston m/c on a Rex. Sometimes you don't get all the story with threads like that - the bloke who reckoned that the EX500 m/c was great, only said so after a lot of other mods had been done to his bike - braided lines, HH pads etc etc. These things alone make a heap of difference. He also made no mention of the different ratio on the stock EX500 brake lever, compared to the OEM Rex lever.......this is a small, but critical issue...........
When I converted from the stock OEM 5/8" m/c (16mm) on the MFP12, to a radial 3/4" (19mm) m/c - the difference in the braking force was incredible. Also, the effort at the lever was much reduced. Basically, my experience was everything that HIllbilly said could NOT happen when you go to a larger m/c piston size. So based on my experience, I reckon old mate Hillbilly has been smoking too much corn-cob pipes........but that is just imho of course ! According to him, I should have experienced much reduced braking !!!




Unfortunately - I have to throw a spanner in the works as well !!!

I have a good mate who is an hydraulic engineer at the ANU. He knows shit about hydraulics, I just listen to him.....He told me years ago when I went racing......to improve the brakes on the Black Pearl (1980 Z1000) - I should change the m/c from a 5/8" to 1/2" !! So I did - and fitted a 1978 RD400 m/c. It worked really well - but there was one important other change - the brake lever we used on the RD400 m/c, was not a stock Yamaha part - it was a modified Kawasaki lever, with a longer 'arm' that pressed onto the end of the piston. We had to change the leverage ratio of the brake lever, in order to get the best action out of the smaller m/c. It made the brakes feel a bit 'wooden' - ie - the feedback through the lever was not as precise as it was with the OEM 5/8" m/c - but the braking 'force' was improved......this is where all the gobblygook on the US forum fell in a heap. Instead of just saying - '...Heh man, use a different leverage ratio on your brake lever, so the extra travel required on a smaller m/c can be achieved easily...' - they carry on with a lot of mud-slinging.
Glad this place is nothing like that !! eh Seiko you raving queer !!

Last edited by Gosling1 on Wed Feb 17, 2010 10:11 pm, edited 1 time in total.
".....shut the gate on this one Maxie......it's the ducks guts !!............."
- laidback
- VIP MEMBER
- Posts: 3307
- Joined: Mon Mar 02, 2009 4:55 pm
- Bike: ZRX
- State: New South Wales
- Location: Wagga Wagga, NSW
Re: Radial calipers on REX
Better leave it until the morning Gos...or some time when you are refreshed...hehehe.Gosling1 wrote:..............
I reckon HH's are the greatest brake pad known to mankind.![]()
just awesome. Cupcake loves his OEM pads, but on the 12 with stock Tokicos, the OEM pads just don't have the same 'bite' as the HH's do. Maybe the OEM pads on a 10 are a different compound anyway ??
I'll check that link out and see what sort of gobblydook they speak....

Mathematics are one thing but gees they make it complicated.
Roady - ZRX1200R
Tracky - ZX9R F1 Team Jerry Atric
I've reached the age where 'happy hour' is a nap.
Tracky - ZX9R F1 Team Jerry Atric
I've reached the age where 'happy hour' is a nap.
-
- KSRC Contributor
- Posts: 2075
- Joined: Sun Apr 17, 2005 1:00 pm
- Location: Toowoomba/Ipswich Queensland
Re: Radial calipers on REX
I know someone *ahem* who uses 5c pieces to shim brakelevers to to master cylinders on GT Kawasakis when the brakes are insufficient.the brake lever we used on the RD400 m/c, was not a stock Yamaha part - it was a modified Kawasaki lever, with a longer 'arm' that pressed onto the end of the piston. We had to change the leverage ratio of the brake lever, in order to get the best action out of the smaller m/c.

2 X ZRX1200R 4 X ER6N, GT550, 1988 ZX-10, 4 X GPZ250R, 4 X GPZ900R and GPZ750R
Yeah I like Kawasakis.

- Gosling1
- Team Donut
- Posts: 13826
- Joined: Mon Jun 20, 2005 9:30 pm
- Bike: ZX2R
- State: New South Wales
- Location: Anarchy Road
- Contact:
Re: Radial calipers on REX




".....shut the gate on this one Maxie......it's the ducks guts !!............."
- seiko1
- Apprentice Post Whore :-)
- Posts: 7643
- Joined: Wed Jan 14, 2009 8:36 pm
- Bike: ZX14R
- State: Victoria
- Location: Geelong
Re: Radial calipers on REX
If it works....use it!Gosling1 wrote:![]()
![]()
really ?? that sounds like my type of engineering solution !!!

Policy - Find something simple.....and Complicate it!
-
- KSRC Contributor
- Posts: 2075
- Joined: Sun Apr 17, 2005 1:00 pm
- Location: Toowoomba/Ipswich Queensland
Re: Radial calipers on REX
It is a cheap mod, but don't overdo it- brakes lose freeplay and drag. 

2 X ZRX1200R 4 X ER6N, GT550, 1988 ZX-10, 4 X GPZ250R, 4 X GPZ900R and GPZ750R
Yeah I like Kawasakis.

- TopCat
- KSRC Member
- Posts: 266
- Joined: Thu Oct 21, 2004 10:30 pm
- Bike: ZRX
- State: Victoria
- Location: Melb
Re: Radial calipers on REX
Thanks, now I understandGosling1 wrote:blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
Seiko you raving queer !!

TopCat
73% of internet statistics are made up on the spot
73% of internet statistics are made up on the spot
- TopCat
- KSRC Member
- Posts: 266
- Joined: Thu Oct 21, 2004 10:30 pm
- Bike: ZRX
- State: Victoria
- Location: Melb
Re: Radial calipers on REX
Gedday, looking for advice / help
The radial calipers were a great improvement over the stockers.After bleeding them I had a beautiful firm lever with little movement. However there was little feel at the lever. So I shelled out and bought the radial m/cyl from the 09 ZX-6R (same as the calipers).
Bleeding them tonight, there are no more bubbles coming from the lines, just clear fluid. However the lever travels straight back to the bar. If I pump the lever a few times, it builds up pressure and seems to hold that pressure. However, there's still a fair bit of movement at the lever. I was careful not to let the fluid drop below the "low level" in the master cylinder when bleeding the brakes.
Never having owned a bike with a radial m/cyl before, should I expect more travel at the lever compared to a non-radial m/cyl. Talking to a guy in work today, before I started bleeding the brakes, he mentioned to tie the lever back to the bar as far as possible when finished and leave overnight (using an ocky strap / clamp). He maintained that this will facilitate any air still trapped being released. I've done this.
I would really appreciate any advice as to whether all is ok or to try something else.
Thanks,
Tony

The radial calipers were a great improvement over the stockers.After bleeding them I had a beautiful firm lever with little movement. However there was little feel at the lever. So I shelled out and bought the radial m/cyl from the 09 ZX-6R (same as the calipers).
Bleeding them tonight, there are no more bubbles coming from the lines, just clear fluid. However the lever travels straight back to the bar. If I pump the lever a few times, it builds up pressure and seems to hold that pressure. However, there's still a fair bit of movement at the lever. I was careful not to let the fluid drop below the "low level" in the master cylinder when bleeding the brakes.
Never having owned a bike with a radial m/cyl before, should I expect more travel at the lever compared to a non-radial m/cyl. Talking to a guy in work today, before I started bleeding the brakes, he mentioned to tie the lever back to the bar as far as possible when finished and leave overnight (using an ocky strap / clamp). He maintained that this will facilitate any air still trapped being released. I've done this.
I would really appreciate any advice as to whether all is ok or to try something else.
Thanks,
Tony

TopCat
73% of internet statistics are made up on the spot
73% of internet statistics are made up on the spot
- seiko1
- Apprentice Post Whore :-)
- Posts: 7643
- Joined: Wed Jan 14, 2009 8:36 pm
- Bike: ZX14R
- State: Victoria
- Location: Geelong
Re: Radial calipers on REX
Sounds like that Master is rooted TC 

Policy - Find something simple.....and Complicate it!
- TopCat
- KSRC Member
- Posts: 266
- Joined: Thu Oct 21, 2004 10:30 pm
- Bike: ZRX
- State: Victoria
- Location: Melb
Re: Radial calipers on REX
.. shouldn't be as it's a brand newyseiko1 wrote:Sounds like that Master is rooted TC

TopCat
73% of internet statistics are made up on the spot
73% of internet statistics are made up on the spot
- seiko1
- Apprentice Post Whore :-)
- Posts: 7643
- Joined: Wed Jan 14, 2009 8:36 pm
- Bike: ZX14R
- State: Victoria
- Location: Geelong
Re: Radial calipers on REX
And...........................?TopCat wrote:.. shouldn't be as it's a brand newyseiko1 wrote:Sounds like that Master is rooted TC

Ever heard of D.O.A?
I see it a lot

Policy - Find something simple.....and Complicate it!
- plane
- KSRC Member
- Posts: 307
- Joined: Mon Sep 13, 2004 11:29 pm
- Bike: ZRX
- State: Queensland
- Location: Whitsundays
- Contact:
Re: Radial calipers on REX
Hi Tony,
Make sure you bleed the master cylinder itself. Crack the banjo bolt at the master cylinder and I bet you get bubbles. Or you could tilt the mastercylinder upwards (unbolt it from the bars of course) and very slowly apply the lever.
Cheers,
Pete
Make sure you bleed the master cylinder itself. Crack the banjo bolt at the master cylinder and I bet you get bubbles. Or you could tilt the mastercylinder upwards (unbolt it from the bars of course) and very slowly apply the lever.
Cheers,
Pete
Live Fast, Die Sideways


Re: Radial calipers on REX
Did that when I bled the new lines onto the zed, it worksplane wrote:Hi Tony,
Make sure you bleed the master cylinder itself. Crack the banjo bolt at the master cylinder and I bet you get bubbles. Or you could tilt the mastercylinder upwards (unbolt it from the bars of course) and very slowly apply the lever.

Good to see ya back Pete
Phil
2018 Z900RS
2017 Z125 Pro
HCC - Road Captain
2018 Z900RS
2017 Z125 Pro
HCC - Road Captain