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will a katana master cylinder improve my braking?

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I was playing around with idea of throwing a katana or some streetbike master cylinder on my bike along with a ss line to improve my sm's braking for better stoppies.I see that the katanas master cylinder size is 14mm while ours is only 12mm I believe? I also think the factory brake light will plug right in and hopefully my asv lever will work also.anybody got any ideas?

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all i can tell you is that i tryed an after market rear caliper on my harley and used the stock master cyl. and it kept dragging and locking up. I would try it unless someone know's it will not work.

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Before upgrading the caliper and rotor on my SM, I installed a 14mm master from a 2005 Katana to be sure that it fit and worked properly before installing the new caliper. (The stock SM master is 12.7mm and I think the "S" has a 12mm master) Just installing the 14mm master made a HUGE difference and it uses the same brake light switch, however the lever is different than the DRZ. The banjo fitting for the DRZ is also a different thread, so be sure you get the right banjo for the Katana master.

I ran the 14mm master for about 2 weeks before finishing the new front wheel and brake set-up. I wish I would have changed the master a long time ago, I only went to a 14mm because I felt it was needed for the 4 piston caliper I was planning to install. I am still running my stock brake line and I am very happy with the feel. At some point I may get a steel line but I think the master makes a bigger improvement than just a line and it is a lot cheaper... I found a 2005 master for $20.00 and then spent $35.00 for the pair of levers...

I'm not sure how this would work for the "S" model, it may be a little too much for off-road, but it works great for pavement.

The angle of the top is a little different, but it also seems to have a larger capacity than the stock DRZ master.

DRZ%252014mm%2520master%25202.jpg

I bought some levers for a Katana / SV650 and only had to modify the clutch lever a little to make it work properly. I'm not sure if you can modify a DRZ brake lever to fit the Katana master.

DRZ_2-5-12%2520ktm%2520guards_sm.jpg

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you also have the best possible grips on display too. those cut my pain down to almost nothing on 8 hour rides. nice bit of info you provided, kudos !

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The answer is - what do you mean by better brakes? A 14mm master to replace a 12 master will give a firmer lever feel and require more lever pressure to achieve the same braking force. My guess is you want a smaller master for more hydraulic leverage. An "E" model comes with a smaller master for the same caliper piston size and same rotor diameter as the "S". 10 or 11mm, I don't remember right off.

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More effort would be required. It translates to a "stiffer" feel. But there would be more fluid pressure at the caliper with less movement of the lever. More required force at the lever, but less lever movement. It all depends on what you want out of your brakes. With the DRZ, a lot of folks find that they are wanting more braking power. At that point, upgrading to a slightly larger master cylinder might be the solution. Going larger than 16mm would be too much. 14mm should be a really good size. More force at the caliper than what the stock unit can provide, but not too stiff with a good amount of interpreted feel.

Going to a smaller master means less force being exerted on the rotor. More potential control of the force available too you, but just less of it.

Edited by fish_bate

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More effort would be required. It translates to a "stiffer" feel. But there would be more fluid pressure at the caliper with less movement of the lever. More required force at the lever, but less lever movement. It all depends on what you want out of your brakes. With the DRZ, a lot of folks find that they are wanting more braking power. At that point, upgrading to a slightly larger master cylinder might be the solution. Going larger than 16mm would be too much. 14mm should be a really good size. More force at the caliper than what the stock unit can provide, but not too stiff with a good amount of interpreted feel.

Going to a smaller master means less force being exerted on the rotor. More potential control of the force available too you, but just less of it.

i think i like the idea of a firmer leaver a lot more than a squeshy one thats easier to pull.ill get one ordered.anybody know if my asv lever i got on there now will work with it?

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I run a master cylinder off of an R1 on my bike, with standard caliper and SS lines. The piston size is 15.8mm (5/8ths). I love it. The lever is VERY firm but when you ride it it's actually also very progressive. As others have said you need more force to get the same braking, but i find you get a very good feel through the lever and it stops incredibly well as long as you have strong enough fingers! LOL.

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I just wanted to chime in with some hydraulic brake theroy 101...

Frcition is caused by force on the pads, force is caused by pressure. (at the caliper) assuming the same caliper is used, the only thing that will change the pressure is force applied to the master cylinder piston (swqueeze the lever). because the force generated is determined by the fluid pressure and the applied area (piston bore), a larger piston will develop a higher force for a given pressure.

Think of it this way, when the pressure is suplied (caliper) a big piston is needed to generate a large force from a small pressure. but when your scrawny hand (master cylinder) is providing the force, a small area is needed to generate the same pressure.

In short, a largeer MC bore will create LOWER pressure in the system and LESS stopping power for the same amount of "squeeze" at the lever. of course, if the stock (smaller bore) MC is running out of lever travel all is moot...

so the katana MC will get you: a better lever feel, less lever travel, and LESS ultimate stopping power unless lever travel is an issue with the other setup.

In my experience, i can lock the front wheel on pavement at ~15mph (haven't tried any faster) with a completely stock front brake, and i did not run out of lever travel...

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I would think that lever travel would only be an issue if you have air in the system, low fluid, worn brake line, etc.

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I just wanted to chime in with some hydraulic brake theroy 101...

Frcition is caused by force on the pads, force is caused by pressure. (at the caliper) assuming the same caliper is used, the only thing that will change the pressure is force applied to the master cylinder piston (swqueeze the lever). because the force generated is determined by the fluid pressure and the applied area (piston bore), a larger piston will develop a higher force for a given pressure.

Think of it this way, when the pressure is suplied (caliper) a big piston is needed to generate a large force from a small pressure. but when your scrawny hand (master cylinder) is providing the force, a small area is needed to generate the same pressure.

In short, a largeer MC bore will create LOWER pressure in the system and LESS stopping power for the same amount of "squeeze" at the lever. of course, if the stock (smaller bore) MC is running out of lever travel all is moot...

so the katana MC will get you: a better lever feel, less lever travel, and LESS ultimate stopping power unless lever travel is an issue with the other setup.

In my experience, i can lock the front wheel on pavement at ~15mph (haven't tried any faster) with a completely stock front brake, and i did not run out of lever travel...

The theory works if all factors are the same except the cylinder bore. The lever ratio is yet another variable...

The lever ratio of the DRZ and the Katana are NOT the same. The distance from the lever pivot to the center of the cylinder bore is greater on the Katana.

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Ah, but of course. I was indeed writing assuming bore size was the only variable. thank you for pointing that out. I should have been saying "force at the MC cylinder" not "force on the lever"

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I did a little research before buying the parts to upgrade my complete brake system. I felt the stock SM master would not be enough for the 4 piston caliper I planned to use. however, I did not expect to have just the 14mm master make the improvement that it did with the stock SM caliper.

Back to the lever ratio...

I do not think that it takes much to make a big difference and another type of 14mm master from another manufacturer could have a completely different result, I think I may have just been lucky.

Using the stock DRZ lever and the stock Katana lever, here is the difference.

Brake%2520levers.jpg

I only bought the Katana master because I felt it would be better with the new caliper. I still say that the 14mm Katana master offered a nice improvement with the stock caliper. You can buy them at a very reasonable price and it is a no-brainer swap.

The 14mm also works well with the new caliper and 320 rotor...

Using the forged magnesium wheel that I had access to, there were not any off the shelf parts that would have bolted up anyway.

Overall, I spent a lot more time than money on this, but I'm very happy with the end result...

aIMG_6243c.jpg

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There is a range if acceptable hydraulic ratios (master piston area to total caliper pistons area), That is why you see larger master pistons used with systems with multiple calipers. When you throw in largrer rotors, 6 piston calipers, brake levers with different mechanical leverage, things get confusing. So whatever works. But still, in general, everythings else staying the same - increase the master piston diameter, hydraulic system pressurre will be lower for the same force applied to the brake lever = less braking.

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I did a little research before buying the parts to upgrade my complete brake system. I felt the stock SM master would not be enough for the 4 piston caliper I planned to use. however, I did not expect to have just the 14mm master make the improvement that it did with the stock SM caliper.

Back to the lever ratio...

I do not think that it takes much to make a big difference and another type of 14mm master from another manufacturer could have a completely different result, I think I may have just been lucky.

Using the stock DRZ lever and the stock Katana lever, here is the difference.

Brake%2520levers.jpg

I only bought the Katana master because I felt it would be better with the new caliper. I still say that the 14mm Katana master offered a nice improvement with the stock caliper. You can buy them at a very reasonable price and it is a no-brainer swap.

The 14mm also works well with the new caliper and 320 rotor...

Using the forged magnesium wheel that I had access to, there were not any off the shelf parts that would have bolted up anyway.

Overall, I spent a lot more time than money on this, but I'm very happy with the end result...

aIMG_6243c.jpg

what caliper is this?

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Looks like a caliper off an 2006 and up R6....where did you get the caliper bracket? I know those won't fit a spoked wheel.

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Looks like a caliper off an 2006 and up R6....where did you get the caliper bracket? I know those won't fit a spoked wheel.

You are right, it is of a 2009 R6 and it is too wide to work with spoked wheels.

Due to the wheel I was using, there were no "bolt-on" options for brakes and I was not going to spend any time making a bracket to re-use the stock "dirt-bike" caliper. I considered several different types of sport bike calipers, and the radial mount R6 looked like the best option for my use. I had to make the caliper bracket.

I bought a 320mm Ducati/Brembo rotor that bolted up to the wheel and then designed a bracket to work with the R6 caliper. I spent less than $100 for the caliper and 320mm rotor...

DRZ%2520front%2520bracket2.jpg

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