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Gixxer front brake upgrade


scordiaboy515

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thomascrown

You can buy an an aftermarket nissin radial mc that is setup for naked bikes with a mirror mount. Same with the brembo rcs mc.

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thomascrown

FYI, one of the cool things with buying the aftermarket nissin is you can choose the piston diameter on the mc. The gixxers come with the big 18 or 19mm piston, which is higher effort. To give you an idea, the 98 R1, which pioneered the use of the advics calipers on our bike, only runs a 14mm piston, so Yamaha intended for a lower effort mc. You can get the Nissin aftermarket mc in a 16mm, which is the equivalent of of 14mm non radial. Which would essentially give you gen 1 R1 brakes in a radial format. Plus a mount for the mirror.
 
Not bad for 160 bucks:
 
79884_1_l.jpg
 
79886_1_l_2.jpg
 
 

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I know, that looks real nice and I was looking at that gold one on a website just yesterday.
 
I believe the one I'm using is 17.5 mm (11/16 is written in the master cylinder), but I do wonder what
a master cylinder with a smaller piston would feel like.

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  • 5 months later...

I'm going to be doing the same thing iv got the master, brake light switch, and lever, and aftermarket mirror perch. What did you end up doing for the brake lines. Are they custom or are they fz07 or are they gixxer.

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  • 1 month later...

Would have replied much sooner, but I haven't been on here as much, lately.
 
On my FZ07, I used the stock front brake line without a problem.

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  • 3 years later...
On 7/3/2015 at 5:01 PM, scordiaboy515 said:

It's the diameter of the piston inside the master...the bigger the piston the more powerful but less feel....and vice versa 

I know this is a really older thread, but I had to comment.   

 

The exact opposite is true.  The smaller piston will increase braking power, but will increase lever travel.  Bigger piston will decrease braking pressure, but have less lever travel.  The reason for less feel is that you have to squeeze harder to get the same pressure.   I dealt with this when I was installing a single master cylinder to operate all three calipers on an 89 Gold Wing.  I contacted Dr. John Wittner of 80s-90s MotoGuzzi endurance racing fame along with joining Guzzi in redesigning their sport models going into the new millenium.   He filled me in.  The smaller bore increases the power from the lever (of course there is the actual mechanical leverage of the hand lever too), it moves less fluid so the lever will travel closer to the handlebar, but more pressure from the master cylinder.   That is from basic fluid power.   

It is best to know what the brake caliper piston area is and compare to master cylinder piston size.    If you can squeeze one pound at the lever and the piston is one square inch you have one PSI, if the piston is two square inches you have 1/2 PSI .  That is how the master cylinder works.

Now at the caliper if you have one PSI in the line and your piston area is 4 square inches you have 4 pounds pressure.  If you have 8 square inches you have 8 lb pressure.   

That's why you need to know what is what in piston sizes both at the master cylinder and at the calipers.

 

An example of what I'm saying, look at any hydraulic ram,  the pump piston is very small in comparison to the actual ram.   The reason for that is if it is bigger it would take too much effort to work for heavy loads.

Edited by klx678
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On 5/22/2016 at 9:22 PM, YZEtc said:

I know, that looks real nice and I was looking at that gold one on a website just yesterday.
 
I believe the one I'm using is 17.5 mm (11/16 is written in the master cylinder), but I do wonder what
a master cylinder with a smaller piston would feel like.

Again, I know... ancient thread, but the information may help someone.

If you drop from a 17.5 to a 16 you will increase the line pressure, increasing braking power at the caliper.  The question will be if it will move enough fluid to not pull back to the handlebar.   Small changes like 1mm diameter may not be a problem.

I remember a document I had that listed Honda calipers and master cylinders.   One of the old Hurricane master cylinders was like a 14 mm piston operating two twin piston calipers.  When paired up with bigger calipers the brake pressure was huge, but unfortunately pulled virtually back to the handlebar.   

So the trick is to find what the brake caliper piston size is and compare to the master cylinder piston size.   Not easy information to attain.      

Edited by klx678
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Some trial and error experimentation may be required.

I'm going to be doing just that with the 2020 CB300R I got in October. Even though reviews of the bike typically claim the front brake is good, my opinion of it is the opposite:

It stinks, stock, as far as actually braking power goes, and I could not disagree more on that topic.

The 2020 CB300R master cylinder piston diameter is 1/2 inch (12.7 mm). I'm in possession of a 12mm Magura HC1 master cylinder.

I'll let you know how it works once I try it.

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On 7/23/2015 at 7:24 AM, YZEtc said:

I did this to my 2007 SV650K7 back then.
I did it mainly (or, the most apparent advantage that came to my attention after doing it) because of the better shape and feel of the front brake lever.The lever is flatter and longer for more leverage, and the feel when using the brake was very good, indeed.If it actually makes the brake stronger, that's an added bonus.
 
At least the stock front brakes of the FZ-07, with a change to EBC HH pads, in my opinion, are excellent to begin with.
The SV?
Not so excellent, stock.

Where did you buy your pads from?

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13 minutes ago, Jay Z said:

Where did you buy your pads from?

My local Yamaha dealer, the same place I bought my FZ-07 from.

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48 minutes ago, YZEtc said:

Some trial and error experimentation may be required.

I'm going to be doing just that with the 2020 CB300R I got in October. Even though reviews of the bike typically claim the front brake is good, my opinion of it is the opposite:

It stinks, stock, as far as actually braking power goes, and I could not disagree more on that topic.

The 2020 CB300R master cylinder piston diameter is 1/2 inch (12.7 mm). I'm in possession of a 12mm Magura HC1 master cylinder.

I'll let you know how it works once I try it.

Should be more lever travel, but harder braking with less effort.   

One other trick you could try would be to use a single 4 piston caliper if it could be fitted.  They're low buck on ebay.  But definitely do the master cylinder first.  It will be interesting to hear your results.

I understand and believe the radial style master cylinder adds to power, if for no other reason than a straight push on the piston.  Another plus mentioned earlier is if the leverage ratio of the actual lever is higher.  

 

I still have a project I've not gotten done, adapting a CBR900RR brake set up to a Zephyr 550.  If it works it would work on several other models like the Eliminator and the Concours.   Just never got the adapters cut.

Edited by klx678
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11 minutes ago, klx678 said:

Should be more lever travel, but harder braking with less effort.   

One other trick you could try would be to use a single 4 piston caliper if it could be fitted.  They're low buck on ebay.  But definitely do the master cylinder first.  It will be interesting to hear your results.

I understand and believe the radial style master cylinder adds to power, if for no other reason than a straight push on the piston.  Another plus mentioned earlier is if the leverage ratio of the actual lever is higher.  

Honda already took care of the caliper by producing the bike with a 4-piston front caliper, stock. The crummy part of it was the stock pads. I replaced them with EBC HH pads and the brake performance went all the way up to not-bad-at-all, which was a huge improvement.

I do believe the HC1 master cylinder will offer more leverage at the expense of more lever travel required, but since the lever needs to travel very little in order to activate the brake as it sits right now, I think it will be a good trade-off.

Actually, if the stock master cylinder simply had a brake lever that was positioned closer to the handlebar and was not so I had to make a slightly awkward reach for the brake lever, that alone would be a step up. That's what I realized with the 11/16 inch Nissin master cylinder I installed on my FZ-07:

Just the much better positioning of the lever made it feel better by being able to get a more efficient pull on it with my fingers. Then, beside that, was the added leverage and brake power.

Edited by YZEtc
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It would make sense that they might make the brake master cylinder to caliper ratio a bit low, wouldn't want a new rider crashing with too sensitive a brake on the front.  That might explain why the media found the brake to be okay, not too strong, but not too weak.

Clearly your experience tells you that you want that extra power since you can control it.  Makes sense to do the higher ratio.  Sounds like fun trying out something new.   We actually hooked up the OEM master cylinder on the 89 Wing to see what happened.  The lever pulled in to the grip, just catching braking at the grip and hard when it hit.  Just not a good set up for our needs.  For some reason I'm thinking we had a 23.5mm master cylinder (15/16"), the biggest Grimeca made and was recommended for our use by both Wittner and Grimeca.  It had to be fairly big since it was working all three twin piston calipers.  It did the job fairly well, lever travel about half way to the grip and with decent control.

Here is Wittner's Guzzi, notice no rear brake lever.  They used the hand lever only and a proportioning valve between the front and rear circuits:

tumblr_o7pcpxXAY01qelkhfo1_1280.jpg

 

When it comes to levers I went to adjustable short levers on my XSR to get levers closer to the grip, I have smaller hands (no jokes please😁) and like to use two/three finger brake and three finger clutch.  The stock set up on the front was fine with some adjustment, but the clutch was fixed.  

Edited by klx678
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  • 3 weeks later...

so what size piston does the gixxer master have? also what size piston would i need in radial to match the fz axial set up? 

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Some actual engineers (ze Germans at Magura) have done real math, and came up with 15mm diameter recommended for their radial brake master on the FZ07 . I run the HC1 on mine in 15mm (track & street), it works great, especially great modulation, and one finger stoppies if desired (I use Vesrah pads, so YMMV). Of ocurse, this is not for the "bigger is better" crowd ;) .

Here is the link to the German approval certificate for the HC1/HC3 master from Magura:

https://www.magura.com/media/1060842/abe-hc1_598739_61376_2019.pdf

 

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I have used this chart through the years when swapping around brake components. Read the article to understand the ratio system he is using to determine between wooden and spastic, then size up your components. 

https://www.vintagebrake.com/mastercylinder.htm

I don't know who makes the brake calipers on our bikes ( there are no markings I can see), but the master cylinders are very nicely made Brembo units. Brembo is as good of a brake component that money can buy. 

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The brake calipers are Advics, piston sizes are 30 and 27mm diameter, makes for a total of about 2559 mm^2 of piston area.

So according to the vintage chart 27:1 or 23:1 ratio) I should be using an 11 or 12mm master (so I can feel some line & caliper flex ;) ). Pretty sure that would pull all the way to the handlebar.

Brake master has no markings, Brembo usually puts their "b" logo on there.

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5 hours ago, kolby said:

Some actual engineers (ze Germans at Magura) have done real math, and came up with 15mm diameter recommended for their radial brake master on the FZ07 . I run the HC1 on mine in 15mm (track & street), it works great, especially great modulation, and one finger stoppies if desired (I use Vesrah pads, so YMMV). Of ocurse, this is not for the "bigger is better" crowd ;) .

Here is the link to the German approval certificate for the HC1/HC3 master from Magura:

https://www.magura.com/media/1060842/abe-hc1_598739_61376_2019.pdf

 

The math isn't hard, getting government approval to have the part able to be considered legal replacement equipment in Germany is what was real.   They submitted necessary engineering information to the government for said approval.  Otherwise it would be totally illegal to use the part on the bike.   No such case in the U.S.

Just sayin' if you calculate out the piston area for the calipers and work out the pressure at the master cylinder based on its area you can find what the PSI is for the stock system then figure which master cylinder would give you the performance you want by figuring the pressure output from it in comparison to stock.  But it takes the knowledge of the area of the master cylinder and the calipers.

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2 hours ago, shinyribs said:

I have used this chart through the years when swapping around brake components. Read the article to understand the ratio system he is using to determine between wooden and spastic, then size up your components. 

https://www.vintagebrake.com/mastercylinder.htm

I don't know who makes the brake calipers on our bikes ( there are no markings I can see), but the master cylinders are very nicely made Brembo units. Brembo is as good of a brake component that money can buy. 

Now THAT is of value.   There was a similar chart a Honda Superhawk/Firestorm rider set up, but with all Honda equipment.  The key is going much smaller than OEM will cause extreme lever travel.   Brembo may be helping their set up out by increasing the mechanical leverage of the lever to allow the larger piston to keep lever travel to a minimum.   

All aspects of leverage, hydraulic and mechanical, come into play.   

 

Here is a Google spread sheet to calculate the hydraulic leverage based on piston size and count only.  I don't quite know how to fit in the lever yet, maybe later after I look at a few.  Feel free to make a copy in your google drive by hitting edit and making a copy.  Then let me know if there are any problems with the cells or the work done.  They work for me, but then again I made the sheet.  Link to master cylinder to caliper hydraulic leverage sheet.

 

 

Edited by klx678
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On 1/22/2020 at 5:37 PM, kolby said:

The brake calipers are Advics, piston sizes are 30 and 27mm diameter, makes for a total of about 2559 mm^2 of piston area.

So according to the vintage chart 27:1 or 23:1 ratio) I should be using an 11 or 12mm master (so I can feel some line & caliper flex ;) ). Pretty sure that would pull all the way to the handlebar.

Brake master has no markings, Brembo usually puts their "b" logo on there.

Our stock calipers are Advics? I never heard of that company. Thanks. 

My front master has the Brembo b on the fluid cap. 

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Yep, the same Advic calipers that were used on early R1 and R6 models. Often referred to as ‘blue spot’ on these models, though they came in a range of colours.

Edited by stickshift
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I know Sumitomo was making the calipers when the YZF-R1 came out, which was 1998.

They must have dropped that company and are using another to make the same/similar calipers with the monoblock design and that distinctive plug over each piston bore.

Edited by YZEtc
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