Kawasaki Concours Forum

The C10, aka Kawasaki Concours - The Original => Accessories and Modifications - C10 => Topic started by: Johnj on May 14, 2011, 12:59:53 PM

Title: Front calipers
Post by: Johnj on May 14, 2011, 12:59:53 PM
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.  :banghead:
Title: Re: Front calipers
Post by: GF-in-CA on May 14, 2011, 01:08:01 PM
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,
Title: Re: Front calipers
Post by: throb on May 15, 2011, 05:26:46 AM
  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.
Title: Re: Front calipers
Post by: jfman on July 17, 2012, 06:44:20 PM
Did you use the Concours Bracket or othe bracket from the suzuki?
Title: Re: Front calipers
Post by: enim57 on July 17, 2012, 09:10:24 PM
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
Title: Re: Front calipers
Post by: George R. Young on July 17, 2012, 09:24:09 PM
. . . 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 (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).
Title: Re: Front calipers
Post by: jim snyder on July 17, 2012, 10:32:24 PM
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.   
Title: Re: Front calipers
Post by: enim57 on July 18, 2012, 02:21:03 AM
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 (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
Title: Re: Front calipers
Post by: George R. Young on July 18, 2012, 07:06:31 AM
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.
Title: Re: Front calipers
Post by: jworth on July 18, 2012, 08:47:30 AM
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. 
Title: Re: Front calipers
Post by: Daytona_Mike on July 18, 2012, 09:00:07 AM
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.
Title: Re: Front calipers
Post by: T Cro ® on July 18, 2012, 09:35:14 AM
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.
Title: Re: Front calipers
Post by: Daytona_Mike on July 18, 2012, 10:41:27 AM
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?
Title: Re: Front calipers
Post by: Uglydog56 on July 18, 2012, 08:01:27 PM
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.
Title: Re: Front calipers
Post by: T Cro ® on July 19, 2012, 07:11:36 AM
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.
Title: Re: Front calipers
Post by: Boomer on July 19, 2012, 08:18:57 AM
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 (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.
Title: Re: Front calipers
Post by: enim57 on July 20, 2012, 03:15:56 AM
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
Title: Re: Front calipers
Post by: Daytona_Mike on July 20, 2012, 01:35:53 PM
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)
Title: Re: Front calipers
Post by: T Cro ® on July 20, 2012, 04:50:07 PM
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 
Title: Re: Front calipers
Post by: Daytona_Mike on July 20, 2012, 05:28:09 PM
ROFL !! That was great. I needed a good laugh.
Title: Re: Front calipers
Post by: T Cro ® on July 20, 2012, 06:49:58 PM
ROFL !! That was great. I needed a good laugh.

I'm glad to entertain.....  ;)
Title: Re: Front calipers
Post by: enim57 on July 22, 2012, 08:18:16 PM

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.

This does not relate to the subject in question as one of the sufaces has seriously deformed therefore giving additional mechanical grip and coefficient of friction. Conversely when traveling in sand the opposite is done and tyres are deflated or wider ones used to give a greater contact area. Both of these examples are not relevant.

I understand pressure it's been part of my working life but there is more than just pressure involved here, unfortunately people are fixating on just this part. There is no denial as vehicles have got heavier and faster that contact (friction) areas have got larger in all areas that need grip - brakes & tyres. This wouldn't have hapened if it wasn't necessary, otherwise we would still have skinny tyres and small linings.

Read these quotes below from Wikipedia:

"Surface roughness and contact area, however, do affect kinetic friction for micro- and nano-scale objects where surface area forces dominate inertial forces."

"The strength of the approximation is its simplicity and versatility – though in general the relationship between normal force and frictional force is not exactly linear (and so the frictional force is not entirely independent of the contact area of the surfaces), the Coulomb approximation is an adequate representation of friction for the analysis of many physical systems."

"Despite being a simplified model of friction, the Coulomb model is useful in many numerical simulation applications such as multibody systems and granular material. Even its most simple expression encapsulates the fundamental effects of sticking and sliding which are required in many applied cases, although specific algorithms have to be designed in order to efficiently numerically integrate mechanical systems with Coulomb friction and bilateral and/or unilateral contact.[25][26][27][28][29] Some quite nonlinear effects, such as the so-called Painlevé paradoxes, may be encountered with Coulomb friction."


This has become a sizeable thread, how much more can be said?, Now let's get on to tyres, oil, or which year was the best model. ::)

Regards, Russell
Title: Re: Front calipers
Post by: mdr on July 23, 2012, 08:25:20 AM
This has become a sizeable thread, how much more can be said?, Now let's get on to tyres, oil, or which year was the best model. ::)

Maybe just mentioning my favorite braking upgrade.  A set of 1.1 Sonic Springs + RaceTech Gold Valves.  Allows a lot more braking force before the front end dives excessively, and therefore increases pad pressure, braking torque and reduces braking distance and pucker factor.  All this with stock brake components.

Oh, and the black ones, whatever gets changed regularly and the '01.  Duh.  Next ;)
Title: Re: Front calipers
Post by: Boomer on July 23, 2012, 10:24:01 AM
Russell, thought you'd like to know that I fitted your brackets this weekend with the Chinese rotors on my '89.
All went very well but I had to put a washer (spacer) between your brackets and the fork legs to get the rotor to line up with the calipers on both sides.
Once that was done it all works great and looks so much better than it did with ZRXMopars brackets.
Thanks mate.
Title: Re: Front calipers
Post by: enim57 on July 24, 2012, 12:16:15 AM
Hi George,
Good to hear the brackets are on. The caliper will be closer to the wheel side of the disc but should not rub on it. Putting a washer in between will certainly help to even out the clearances. I thought about putting the washers on mine but have not done it - no problems so far. Glad you are pleased with the result.

Thanks & regards, Russell
Title: Re: Front calipers
Post by: Boomer on July 24, 2012, 09:16:26 AM
It was rubbing slightly with the chinese wave rotors but only on the peaks of the waves.
It's now smack bang dead centre and stops on a penny.  ;D 8)
At the moment the brakes are better than those on my C14.  ::)
That also had new chinese rotors and there is a slight vibe/rumble from the front when I brake hard.
However as the rotors/pads bed in it's getting better.
Title: Re: Front calipers
Post by: enim57 on July 25, 2012, 07:25:11 PM
Hi George,
Thanks for the feedback, interesting. You're the first person to mention the rubbing and mine have clearance regardless of which discs I used (OEM, my manufactured carbon steel, and now Chinese), I wonder what the difference is. Anyway it doesn't matter - I believe you. If I sell any more brackets I'll include stainless steel washers in the kit. Thanks again.

Regards, Russell
Title: Re: Front calipers
Post by: T Cro ® on July 25, 2012, 08:13:05 PM
Hi George,
Thanks for the feedback, interesting. You're the first person to mention the rubbing and mine have clearance regardless of which discs I used (OEM, my manufactured carbon steel, and now Chinese), I wonder what the difference is. Anyway it doesn't matter - I believe you. When I sell more brackets I'll include stainless steel washers in the kit. Thanks again.

Regards, Russell

Fixed that for ya.....  :)

If you take a look at McMaster they sell S. S. Shimming Washers as well as Precision Flat Washers that have very close tolerances for repeatability. They are more costly but this is what I sell with my Shift Linkage so that I'll never be stuck with not sending enough washers and shims with my kits.
Title: Re: Front calipers
Post by: enim57 on July 26, 2012, 12:37:39 AM
Thanks Tony,
I had a look at their website and found the shimming washers. I'm in Australia but now that I know what to look for I will do a search here. Thanks again.

Regards, Russell
Title: Re: Front calipers
Post by: diego092409 on November 17, 2013, 07:24:23 AM
Has anyone tried to put radial mount calipers on their C10?

I have been looking around on eBay and the difference in used radial mount versus axial mount calipers is negligible and in some cases cheaper. In my mind, fabrication of a bracket would be straightforward and would allow the opportunity to put larger rotors on down the road by means of only changing the bolts and adding spacers to make up the difference.

Additionally, if we are talking about upgrading the calipers, wouldn't it make sense to upgrade the master cylinder as well?  Can the original master cylinder really provide the volume and pressures that will be needed with doubling if not tripling the number of pistons they are feeding. This is completely theoretical assuming that we are limited by compressive damping of the forks.
Title: Re: Front calipers
Post by: T Cro ® on November 17, 2013, 04:45:21 PM
No manf supports us by making any sort of brackets for calipers so you would be "one of the first" to try adapting radial calipers to the stock front end.

As to a bigger master cylinder that it not always the need, while slightly differing in reservoir size the masters on the Concours and say the ZRX are the same (5/8") size and there you go from 4 slightly larger pistons to 12 fairly small pistons. And for myself I used a smaller (1/2") bore master on my ZRX brakes as it builds higher pressure but with less volume so it actually improves the feel of the brakes without being overly grabby.
Title: Re: Front calipers
Post by: Boomer on November 18, 2013, 05:04:51 AM
The only real difference between a Radial Caliper and a "normal" one is the way that it bolts to the fork.
The mounting bolts are Radial to the axle rather than Parallel to the axle.
Making a radial mount for the C10 is going to be a PITA and I'm not sure if the gains are worth it.
Now a Radial master cylinder might be a worthwhile fit.
Title: Re: Front calipers
Post by: enim57 on November 18, 2013, 06:02:02 PM
Well I'm going to do it again and probably create more contoversy by stating radial brakes do not have more stopping power than an all things being equal parallel brakes, and will make no difference to the C10 at all. George is correct. Radial brakes came about because of vibration during braking on bikes with USD forks.

Read this (scroll down to middle of page): http://www.carbibles.com/brake_bible.html (http://www.carbibles.com/brake_bible.html)

Regards, Russell
Title: Re: Front calipers
Post by: jworth on November 18, 2013, 07:58:16 PM
I've found myself confused by all of the hulabalu about radial brakes.  I've never figured out how it made any difference from a mechanical advantage perspective.  Granted I'm not a huge student thereof.  The mention of vibration in USD forks makes some sense since those forks would have narrow diameters and perhaps more flex at the bottom.  I can't see how there is significant flex on regular forks.  So I'm still left to think that it's really more of just a latest greatest whiz bang marketing thing. 

Keep thinking though people.
Title: Re: Front calipers
Post by: nevadazx12 on November 20, 2013, 05:11:53 PM
Here is an article and chart showing the relationships between master cylinder size and the calipers.  Bigger on the MC may not always be better.  In the case of my old BMW they were too big and made for very heavy braking, not very efficient and not too progressive.  In many cases the smaller the MC size the better the feel, and better brakes.

http://www.vintagebrake.com/mastercylinder.htm (http://www.vintagebrake.com/mastercylinder.htm)