Front calipers

[Johnj]

There was a topic about what front calipers fit without adapters. And I think I heard a SV-650 front calipers were a bolt on. 

[GF-in-CA]

Yes, the SV650 calipers are a direct fit to the later C10 (1994-2006).  The same calipers are used on a number of bikes, including the V-strom (both 650 and 1000), the GPz1100 (ZX11E), and the ZR7S.  The caliper pistons actually have a smaller area than on the C10 calipers, so on paper, they don't have the same clamping force as the C10 calipers.  They may be stiffer calipers, leading to better lever feel, but until someone does the swap, we won't know that for sure.  HTH,

[throb]

  Just an update on that.  Yesterday I swapped the Tokico caliper (presumably from a V-Strom or similar) that was on the left side of my front brakes with an OE from an '04.  I also rebuilt the caliper prior to installation and it has new EBC HH pads.  The lines were bled as well (got some nasty brown stuff out from the right side)! 
  On a test run, I noticed no remarkable improvements nor did it seems any worse.  Mind you, I was purposefully doing some hard, controlled front braking to make certain all worked as it should when I may need it to, but there was nothing that felt different by the seat of the pants.
 So I guess the best I can tell you is the DL650 bracket bolts right up and will work on these bikes, but if you are just going to use the stock calipers there's probably no real incentive.  Getting the adapter to go to upgraded calipers would probably be an entirely different story.

[jfman]

Did you use the Concours Bracket or othe bracket from the suzuki?

[enim57]

There are 2 things that give better braking:
1) radius of force (caliper to axle distance), torque - think of extending a spanner to make it easier to undo a nut.
2) force (being friction), 3 things acheive more friction: 1) better friction materials, 2) more friction area, 3) more pressure. 4 piston calipers acheive the last 2 (area & pressure). When I converted from OEM '86 calipers to 4 piston Nissin calipers I got 33% more pad area and 136% more piston area - which is pressure.

If you do the maths you will find a change of calipers yeilds a far greater result than going to a 20mm diameter bigger disc which is only 10mm bigger on radius.

Regards, Russell

[George R. Young]

. . . 3 things acheive more friction: 1) better friction materials, 2) more friction area, 3) more pressure. 4 piston calipers acheive the last 2 (area & pressure). . . .

My mind balked at the "more friction area", so I went googling and found
http://stoptech.com/technical-support/technical-white-papers/brake-system-and-upgrade-selection
It says "3) Only increasing the effective radius of the disc, the caliper piston area, the line pressure, or the coefficient of friction can increase brake torque. Increasing the pad area will decrease pad wear and improve the fade characteristics of the pads but it will not increase the brake torque."

So more pad area is a good thing but not for increasing braking force (says the guy with the bone stock brake caliper setup).

[jim snyder]

Going to the 4 pots was a no brainer. The first time I applied the front brakes I knew it was money well spent. I even put a 4 pot rear caliper from a 900 Vulcan on the "silverbullet" (with slight modification of course) Many have asked why I bothered with changing the rear, as you can lock up the rear brake with the stock rear caliper.
My answer is simple, the 4 pot rear gives more braking ability with much less effort. And surprisingly its not as grabby as it was with the stock 2 pot.   

[enim57]

My mind balked at the "more friction area", so I went googling and found
http://stoptech.com/technical-support/technical-white-papers/brake-system-and-upgrade-selection
It says "3) Only increasing the effective radius of the disc, the caliper piston area, the line pressure, or the coefficient of friction can increase brake torque. Increasing the pad area will decrease pad wear and improve the fade characteristics of the pads but it will not increase the brake torque."

So more pad area is a good thing but not for increasing braking force (says the guy with the bone stock brake caliper setup).

That sounds contradictory to me, it states increasing the piston area works but increasing the pad area (the pistons are pushing on) doesn't? Why should it work on one area but not on the other? Imagine if the pad area was only the size of a small postage stamp, how much braking do you think you would have? You would be squeezing that brake lever a lot harder to get the same braking result. Notice when vehicles get heavier (bikes-cars-trucks-trains) the friction area of their brakes is bigger?. Why have some manufactureres gone to 6 piston calipers? More friction area.
What can be hard to visualise is the force that is applied to the disc is done so via pressure and the formula for pressure is P=F/A, to get this back to force alone the formula becomes F=PxA. Therefore, for a given pressure an increase or decrease in area will result in a corresponding increase or decrease in force.

I hope this makes sense.

Regards, Russell

[George R. Young]

If you increase the piston area, the force increases. The fluid only pushes on the piston area. If you increase the pad area (without increasing the piston area), the force doesn't increase.

[jworth]

Friction works independently of area, at least the friction we're talking about here.  The force of friction is equal to the coefficient of friction time normal force.  Not trying to beat anyone up here, just spread some knowledge.  Pressure here really only applies to the hydraulic pressure.  Pressure within a hydraulic system is equivalent at all points within the system.  Therefore, given a greater piston area, the total force applied to the break pads is greater.  So say the pressure is 50 psi.  If there is a total of 6 square inches of piston area, then that's a total of 300 pounds of force being applied to the brake pads/rotor.  This is also why the piston at the master cylinder is so small in relation.  You can apply via the leverage of he brake lever so much force.  If that force is applied to a smaller area the resultant pressure is greater. 

[Daytona_Mike]

Interesting discussion. We also know for a fact that 6 pots dont work or stop as well as 4 pots. Same line  pressure, more area.
Also, 320mm  rotors stop much better than 300mm. The increase is very dramatic and another benefit of 320 rotors, they last much longer.

[T Cro ®]

Interesting discussion. We also know for a fact that 6 pots dont work or stop as well as 4 pots. Same line  pressure, more area.
Also, 320mm  rotors stop much better than 300mm. The increase is very dramatic and another benefit of 320 rotors, they last much longer.

But what 4 potters? Newer ones that have improved design features and less flexation.

[Daytona_Mike]

But what 4 potters? Newer ones that have improved design features and less flexation.

All 4 pot calipers stop better and are less prone to issues than all 6 pot calipers.
Did I say it wrong the first time?

[Uglydog56]

6 pots like to hang up in the bore because there is so little movement, and contribute to unsprung weight.  That's what makes them inferior I believe.

[T Cro ®]

All 4 pot calipers stop better and are less prone to issues than all 6 pot calipers.
Did I say it wrong the first time?

No you speaky just fine..... And yes I do tend to agree that the 4 pot calipers are superior to the 6-potters but I have to wonder if at the time of their conception were they then superior to the then current crop of 4-potters. With that being said I see no reason to pull the stock 6-pot calipers from my ZRX front end or get rid of my spare set as I have no issue whatsoever with the braking power they provide and don't think I'll have issue with the pistons sticking as I tend to actually follow the service guidelines by performing periodic complete cleaning.

Braking systems have so many variables to consider in their overall performance.... Oddly I run a smaller bore master cylinder than stock (with DOT 5) as while it has less flow it can produce an overall higher pressure and makes for a very light feathery brake with one finger but once you grab a fistful it really applies the clamps.

[Boomer]

All you ever needed or wanted to know about the mathematics of braking.
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=7210853&an=0&page=0

Essentially, increased rotor radius = increased braking.
Increased pressure on the pads (different master cylinder) = increased braking.
Increased piston area with same master cylinder = increased braking.
Increased pad area with the same calipers (so the same force pressing on the pads) = less wear

Now, replacing the OEM 2 piston calipers on a 94-06 with a 4 piston Nissin/Tokico will lead to a better feel but no real increase in braking force.
Replacing the OEM single piston caliper on an 86-93 with a 4 piston Nissin/Tokico will lead to a better feel and an increase in braking force due to the increase in pad area.

[enim57]

Boy hasn't this opened a can of worms.
I see a lot of confusion between Force and Pressure, and what we are really talking about is Torque, Torque is being used to stop the wheel rotating just like it is used screw or unscrew a bolt.

Interesting discussion. We also know for a fact that 6 pots dont work or stop as well as 4 pots. Same line  pressure, more area.
Also, 320mm  rotors stop much better than 300mm. The increase is very dramatic and another benefit of 320 rotors, they last much longer.

I think the jury is still out on whether 4 or 6 pots stop better, 6 potters are extremely powerful and I wouldn't ride one without ABS. Larger discs that much better? Not really, that is only an increase of 6.7%, Torque = Force x Radius, for a given Force the improvement is only the increase of the radii (160/150).

Friction area, pad area, surface contact patch, call it what you want, it makes sense that it gives more grip. That is why dragsters use such wide tyres. Imagine leaving all braking elements unchanged and trying to stop your bike on push bike tyres, you won't stop due to lack of friction area. The same applies to brake pads.

Regards, Russell

[Daytona_Mike]

Bigger is better.
 6.7% ? 
Doesn't sound like much but it sure feels like a lot and I like the feel.
I am jealous of the 6 pot guys so I have to make up something to make me feel better about my 4 pots.
Seems like lateley I am singling out you Tony. That's because I am my friend !!

By the way, an increase in pad size is a reduction in pressure per square inch and results in less friction.
 That is why skinny tires are better in the winter. Higher pressure will dig down through the snow. Wide tires will ski on top of the snow. Same force (gravity and the mass of the vehicle is constant) yet more friction with less area.

Sorry  to tell you this Russel but your logic is backwards, Dan explained it correctly.
Think of it this way, put downhill skiis on and have someone push you across the ice. Now put on football cleats and have that same someone push you again. Less surface touching the ice, much more friction yet the force stayed the same.

Drag tires are  different in that the engine can easily overcome the coeffient of friction of skinny tires and there will little no weight transfer (as they quickly melt) from the front of the drag car to the back wheels.  Once you go to a wider tire  the initial   coeffient of friction is the same but now the weight (increase in force) transfers from the front onto the rear tires. This is why drag street pro cars use super soft front shocks. It needs that increase in force which is like installing six pots (or a bigger master cylinder)

[T Cro ®]

Bigger is better.
 6.7% ? 
Doesn't sound like much but it sure feels like a lot and I like the feel.
I am jealous of the 6 pot guys so I have to make up something to make me feel better about my 4 pots.
Seems like lately I am singling out you Tony. That's because I am my friend !!

Seems to me that it has been mutual.... We must both be bored at work eh?

I'll agree with bigger is better to a point of diminishing returns as sooner or later the added weight of huge rotors will increase the gyro affect on the wheel and adversely affect how the bike handles. Otherwise why stop at 320 mm rotors; heck lets go for 340 mm rotors. Yeah!

None of us are re-engineering the wheel here anyway all we are doing is coping in varing stages what the bike manf have figured out along the way and applying it to our dated time machines. If I could go back with the info that I've gleaned since installing my ZRX front end I would have selected the 4-pot binders over the 6-potters as they fit my sliders without adapters.... Or do I open Pandora's box and get 320 mm rotors as well as adapters to fit Radial mount calipers then source a power boosted master cylinder from a BMW 

[Daytona_Mike]

ROFL !! That was great. I needed a good laugh.