upgrading the OEM master cylinder?

[nsrrider]

I'm currently using 1100F rotors and calipers w/stainless lines on my 79. Wondering if there would be a benefit to going to a different master cylinder with increased hydraulic pressure. Any ideas? Thanks!

[alimey4u2]

Not sure if the ratios are different but I would think a matching 1100F master cylinder may be in order. Others who have done this mod may offer a better contribution....

[EMS]

I would agree with Larry. Matching the master with the calipers is a good idea. Everything else is a gamble. The CB1100F calipers are dual pucks. I have no idea how the displaceable fluid volume in there compares to that of the CBX and how the stock master cylinder copes with that. Pressure is a function of piston size and flow (travel).

[Mike Barone #123]

I'm currently using 1100F rotors and calipers w/stainless lines on my 79. Wondering if there would be a benefit to going to a different master cylinder with increased hydraulic pressure. Any ideas? Thanks!

I had a 1100f front and back for years.......the stock 1100f master cylinder worked fine for me at track days and sport rides, but over time it needed rebuilding so my son had a Suz TL1000 master cylinder laying around and this was mounted up quickly so I could give it a try. We did not measure either. Will let you know how this works out once the weather gets above 40 degrees.

Another option to think about would be upgrading the pads ........ big difference. You might ask around on what company and compounds the fast club racer guys use as a start (WERA...or AHRMA HWSB). Dr Tom might be another good source on this since he roadraced CBXs for years. PM me on this and I will get ahold of him for you.

Lets know how it all turns out and welcome to the forums


Mike

[Randakk]

Spend some time here: http://www.vintagebrake.com/mastercylinder.htm

...courtesy of Michael "Mercury" Morse for more useful background info. This will answer all your questions about brake leverage ratios, etc.

Michael is an absolute genius with vintage brake matters. He operates Vintage Brake a terrific source for vintage brake information.

[nsrrider]

I'm currently using 1100F rotors and calipers w/stainless lines on my 79. Wondering if there would be a benefit to going to a different master cylinder with increased hydraulic pressure. Any ideas? Thanks!

update:

I ended up "winging it" and trying out a M/C from a 2008 Kawasaki 1400. Lost the right side mirror mount with this set-up. Dramatic improvement overall with the front brakes. Had to shim the lever (slightly depressed) to get the lever travel and lever position closer to where it needed to be. Brakes are significantly stronger now and I now need to increase fork spring preload to reduce the more noticeable front end dive on the brakes. Not a perfect modification, especially with the loss of the mirror mount but, I would not go back to the OEM.

[Mike Barone #123]

I'm currently using 1100F rotors and calipers w/stainless lines on my 79. Wondering if there would be a benefit to going to a different master cylinder with increased hydraulic pressure. Any ideas? Thanks!

update:

I ended up "winging it" and trying out a M/C from a 2008 Kawasaki 1400. Lost the right side mirror mount with this set-up. Dramatic improvement overall with the front brakes. Had to shim the lever (slightly depressed) to get the lever travel and lever position closer to where it needed to be. Brakes are significantly stronger now and I now need to increase fork spring preload to reduce the more noticeable front end dive on the brakes. Not a perfect modification, especially with the loss of the mirror mount but, I would not go back to the OEM.

Thank you for your update. Updates on technical matters is one of the most important things we can all do on this forum to help each other. In seeing your post I am happy to report updates below like yours which were also based on fitment and testing....the best way in my view.

Master Cylinder
Thanks to John Smarsh another alternative to the stock master cylinder is one from the VFR1000. Fitment was a snap and it is easier to bleed. The results were clearly superior to the 1100f and stock CBX. I think John said the master cylinder piston for the CBX and 1100f was 5mm, but will confirm this with him and adjust this post/update if this is not correct.

However, in saying this I would have liked to have tried your fix since the Kawa 1400 master cylinder is newer and easier to find...plus I do not think the VFR1000 fitment results were quite as good as yours with the Kawa 1400 master cylinder. Maybe someday we will meet up and give a tradeup ride a try.

Few q I have on your Kawa 1400 master cylinder fix
1. Was it from...ZX-1400 or the Concours 1400.
2. Was it used or new
3. What was the price you paid.


Alternative solution for your missing mirror issue when installing the Kawi 1400 Master Cylinder. Bar end mirrors fit either side or both...though I elect to run only the left side.


Front Forks
I have a hybrid front on my 80...da Dawgie...with VFR/Interceptor tubes and 1100f lower. This was a fitment by happenstance in needing parts the day it was being worked on vs planning it this way and Jan figured it all out and did the install. The result was about the same as the stock 1100f I had before since there was no techinical or parts reason for it be better....though again....clearly superior to stock

Early this spring I had the Race Tech Gold Valve and springs installed and the results were a big improvement compared to any stock or 1100f. There was concern before doing this since the Gold Valve actually over rides all the 1100f suspension adjustments including anti-dive ...but fear not ...the result was far better in every way compared to the 1100f or stock CBX including initial compliance over cracks in the road, reduced nose dive on hard braking and all other areas including a real plus....no need for spring pre-load adjuster....the Gold Valve does it all.

Perspective: The Gold Valve was the biggest front end improvement in over 30 years of plodding along with Da Dawgie and trying to get it to realllly handle, but keeping period major components. http://www.racetech.com/





Best and thank you for the update



Mike

[nsrrider]

m/c was used from ebay, off an 2008 ZG1400 concour.....it was maybe 85 bucks or so.....hope this helps!

[Mike Barone #123]

m/c was used from ebay, off an 2008 ZG1400 concour.....it was maybe 85 bucks or so.....hope this helps!

Exactly what I wanted to know and thanks for your reply. I consider this is a great find on your part.


Like I said...actual riding impressions by owners like you that have had success with fixes like this on a CBX is of great value to us all.


Mike

[Jeff Bennetts]

Basically this is the rule of thumb for M/C bore size.

Actually...you don't have to match the bore size, but you do need to be close. If you don't like the way your brakes are now, changing the m/c bore size slightly will make things different.

A smaller m/c bore = less area = less fluid moved per unit of lever travel = more leverage with the lever/less work with a given lever stroke, the downside is that lockup will be easier.

A larger one will do the opposite, ie: require more lever pressure for a given amount of brake force...just the thing if what you've got now is touchy.

If you like your brakes just the way they are, stay with the same size.

[Mike Cecchini]

It's really about how the brakes and brake lever feels presently.

Generally if it's not firm enough you need to go with 1--3 mm larger master cylinder. If it feels "wooden" and takes a lot of lever pressure to make something happen, then dromp down 1--3 mm bore size.

If the lever feels fine (and you're damn sure everything is bled 100% )....... then adjust the pad material compound.

I rebuilt my stock 80 system completely 5--6 yrs ago, installed braided line and some of TIMS "HH" pads..... I couldn't believe the diff and still see no need to install the late model rotors I bought as an upgrade.

Bottom line..... most times if everything is working the way it's designed......the X brakes work fine.

$.02

[zxbob]

F.W.I.W.

I took a master cylinder off of a 2002 Kawasaki ZRX (cause I had a spare) and put it on the CBX. You'll retain your
mirror, it will use your stock levers, and the braking is way better than stock. The ZRX masters are the same from
2000 - 2005 . . . . and you can get them cheap on ebay !

And they dont look bad fitted up on the bike eaither !




Bob

[EMS]

Bob! You should ride with both hands on the handlebars

[barryadam]

F.W.I.W.

I took a master cylinder off of a 2002 Kawasaki ZRX (cause I had a spare) and put it on the CBX. You'll retain your
mirror, it will use your stock levers, and the braking is way better than stock. The ZRX masters are the same from
2000 - 2005 . . . . and you can get them cheap on ebay !

And they dont look bad fitted up on the bike eaither !

Bob

+1
I got a 2002 ZXR12 m/c for my project. It's the same as on my FZ-1. I like that it includes an adjustable lever. These standard Nissin m/c are getting cheaper as most newer bikes have gone to the newer radial m/c with sep reservoir. That upgrade for the CBX was not as economical for me.

Barry

[SanDogDewey]

+1 on the Master Cylinder to Caliper ratios offered at . You should match your master cylinder to the caliper.


I'm using a 2002 919 Master Cylinder on my '80 CBX. You can get a nice one for the cost of the rebuild kit of the CBX Master cylinder. There are usually several on eBay. On my bike it is a good match for the dual piston 900F calipers.

...oh and Dot 5 and stainless lines...hands down. nuff said.