Dual Piston front caliper upgrade. - Kawasaki KLR 650 Forum
1987 to 2007 Wrenching & Mods For maintaining, repair or modifications of Generation 1 KLR's. 2007 and earlier.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 28 Old 08-06-2012, 09:10 PM Thread Starter
Neutral
 
Join Date: Jul 2012
Posts: 1
Dual Piston front caliper upgrade.

Hello all, I am in the process of upgrading my '03 KLR650 with a 320MM rotor and SS brake lines. Furthermore, I also was considering upgrading to a dual piston caliper, only to find out that no such product is offered(to the best of my knowledge and google's). I was wondering if anyone either A) knew where to acquire such a caliper or B) knew if it were possible to use a dual piston caliper from a different bike and fabricate a new bracket in order to fasten it. Speaking on the latter possibility, I have total access to CNC mills and such, and I am well versed in CAD/CAM, and thus could easily fabricate a bracket. Does anyone know of a donor caliper that would suite my needs? Furthermore, does anyone have knowledge of where to most effectively/properly/safely position a caliper/pads over a 320MM disk, pertaining to how I fabricate the bracket? Last but not least, would the extra stopping power from this dual piston caliper be worth all the work? What I mean by this question is, is the stock single piston caliper coupled with the 320MM rotor and SS lines powerful enough to easily lock up the front wheel, thus rendering a dual piston caliper obsolete?

sorry for the egregiously long first post, I hope to become a regularly contributing member to the forum!

thanks,
Rewsiffer
rewsiffer is offline  
Sponsored Links
Advertisement
 
post #2 of 28 Old 08-07-2012, 11:43 AM
2nd Gear
 
pismocycleguy's Avatar
 
Join Date: Nov 2009
Location: Pismo Beach, CA
Posts: 281
Unhappy How about a 2008+ KLR 650?

I believe that the 2008+ KLR's have front dual piston calipers.
Why not try one?
pismocycleguy is offline  
post #3 of 28 Old 08-07-2012, 01:12 PM
4th Gear
 
Spec's Avatar
 
Join Date: Apr 2010
Location: Gateway to Death Valley!
Posts: 1,928
Quote:
Originally Posted by rewsiffer View Post
Hello all, I am in the process of upgrading my '03 KLR650 with a 320MM rotor and SS brake lines. Furthermore, I also was considering upgrading to a dual piston caliper, only to find out that no such product is offered(to the best of my knowledge and google's). I was wondering if anyone either A) knew where to acquire such a caliper or B) knew if it were possible to use a dual piston caliper from a different bike and fabricate a new bracket in order to fasten it. Speaking on the latter possibility, I have total access to CNC mills and such, and I am well versed in CAD/CAM, and thus could easily fabricate a bracket. Does anyone know of a donor caliper that would suite my needs? Furthermore, does anyone have knowledge of where to most effectively/properly/safely position a caliper/pads over a 320MM disk, pertaining to how I fabricate the bracket? Last but not least, would the extra stopping power from this dual piston caliper be worth all the work? What I mean by this question is, is the stock single piston caliper coupled with the 320MM rotor and SS lines powerful enough to easily lock up the front wheel, thus rendering a dual piston caliper obsolete?

sorry for the egregiously long first post, I hope to become a regularly contributing member to the forum!

thanks,
Rewsiffer

Welcome to the forum!

I have a Gen 2 KLR and the front brake is not strong. Takes a good hard squeze to approach locking it up. The Gen 2s have larger/stiffer fork tubes and a more heavy duty wheel (compared to a Gen 1) which should contribute to braking. It's no where near a sport bike/newer dirt bike braking power though. If you're looking for that kind of performance you won't get it unless you want to swap out the entire front end, IMHO.

A larger disk and steel lines will help especially on a Gen 1. Not worth throwing more money at it, dimishing returns and all that, again IMHO.

No eye has seen, no ear has heard, no mind has conceived what God has prepared for those who love him. 1 Cor 2:9
Spec is offline  
 
post #4 of 28 Old 08-07-2012, 01:35 PM
3rd Gear
 
steferf's Avatar
 
Join Date: Jun 2010
Location: Rolla, Mo
Posts: 576
Howdy rewswiffer! And welcome to the fourms.

Check this link out...http://www.klr650.net/forums/showthread.php?t=99914

Guy uses a the 2nd gen SV650 left side caliper, ebc oversized 320 mm rotor, SS brake lines, stock master cylinder, and a custom relocation bracket. Good results, and the master cylinder on the Gen 1 KLR is just the right size (It is possible to run out of master cylinder volume because the caliper's internal volume is too great).

I noticed that you are a cnc guy, check out page 8 of the thread, I posted a dxf and dwg of the relocation bracket. *Note, I did not do the cad work and the file has yet to be verified on a KLR - but you could probably verify the dimensions with a caliper*

I briefly entertained the thought of waterjetting these brackets at cost, but decided it isn't worth the liability. It is sad, but that is the world we live in. The irony is that this bracket actually has much much much greater chance of saving someone's live than malfunctioning and loosing one.

Best of luck, I plan to do this mod in the future.


Also, for those banned from the .net site, just ask and I'll get you the needed information. The summary is this...

2006 Red KLR 650

Modifications:
1)Doohickey Planned and purchased 2)Aftermarket Grips 3)Grip Heaters 4)Happy Trails Hard Luggage Rack 5)20 mm ammo cases planned soon 6)Aftermarket Exhaust 7)Thermobob 8)Happy Trails Fork Brace 9)Stainless Steel Oil Filter 10)Magnetic Drain Plug

See profile visitors post for details and planned mods.

Last edited by steferf; 08-07-2012 at 01:38 PM.
steferf is offline  
post #5 of 28 Old 08-07-2012, 02:46 PM
Banned
 
Join Date: Jan 2010
Location: Mid-Atlantic
Posts: 763
Perhaps a minority opinion, but . . . I don't think a dual-cylinder caliper is necessarily of significant improvement over a single-cylinder model, in terms of stopping power.

The force of friction equals the hydraulic pressure, times the piston area, times the coefficient of friction between the pads and the rotor. Whether there's one, or forty, pistons, I think the formula holds.

Mechanically, a dual-piston caliper aligns the pads more efficiently than a single caliper, but--stop-to-stop, I'd think stopping distance a function of pressure and area, as mentioned.

Larger-diameter rotor? Makes a difference; pads have more leverage in arresting wheel rotation.

Stainless steel-wrapped brake line? Faster, crisper response to lever squeeze.

Full disclosure: Have 320-mm diameter EBC rotor; Gafler Green pads; MSR (I think) stainless steel-wrapped front brake line on '07; quite satisfied with the increased control and modulation available in brake application; don't know absolute stopping distance would test any different from a stock setup. Regardless, the improvement in braking CONTROL alone is worth the mods, IMHO. No interest in springing for dual-piston calipers; but--not agin' 'em!
LoneRider is offline  
post #6 of 28 Old 08-07-2012, 03:07 PM
3rd Gear
 
steferf's Avatar
 
Join Date: Jun 2010
Location: Rolla, Mo
Posts: 576
Quote:
Originally Posted by LoneRider View Post
Perhaps a minority opinion, but . . . I don't think a dual-cylinder caliper is necessarily of significant improvement over a single-cylinder model, in terms of stopping power.

The force of friction equals the hydraulic pressure, times the piston area, times the coefficient of friction between the pads and the rotor. Whether there's one, or forty, pistons, I think the formula holds.

Mechanically, a dual-piston caliper aligns the pads more efficiently than a single caliper, but--stop-to-stop, I'd think stopping distance a function of pressure and area, as mentioned.

Larger-diameter rotor? Makes a difference; pads have more leverage in arresting wheel rotation.

Stainless steel-wrapped brake line? Faster, crisper response to lever squeeze.

Full disclosure: Have 320-mm diameter EBC rotor; Gafler Green pads; MSR (I think) stainless steel-wrapped front brake line on '07; quite satisfied with the increased control and modulation available in brake application; don't know absolute stopping distance would test any different from a stock setup. Regardless, the improvement in braking CONTROL alone is worth the mods, IMHO. No interest in springing for dual-piston calipers; but--not agin' 'em!
I'm not necessary disagreeing with you because I don't know, but what purpose do the multi-cylinder calipers serve then?

Perhaps the multi-cylinder calipers distribute force to larger brake pads more evenly?

2006 Red KLR 650

Modifications:
1)Doohickey Planned and purchased 2)Aftermarket Grips 3)Grip Heaters 4)Happy Trails Hard Luggage Rack 5)20 mm ammo cases planned soon 6)Aftermarket Exhaust 7)Thermobob 8)Happy Trails Fork Brace 9)Stainless Steel Oil Filter 10)Magnetic Drain Plug

See profile visitors post for details and planned mods.
steferf is offline  
post #7 of 28 Old 08-07-2012, 04:48 PM
Banned
 
Join Date: Jan 2010
Location: Mid-Atlantic
Posts: 763
Quote:
Originally Posted by steferf View Post
I'm not necessary disagreeing with you because I don't know, but what purpose do the multi-cylinder calipers serve then?

Perhaps the multi-cylinder calipers distribute force to larger brake pads more evenly?
I think so,
Quote:
Mechanically, a dual-piston caliper aligns the pads more efficiently than a single caliper. . .
LoneRider is offline  
post #8 of 28 Old 08-07-2012, 04:58 PM
3rd Gear
 
steferf's Avatar
 
Join Date: Jun 2010
Location: Rolla, Mo
Posts: 576
Quote:
Originally Posted by LoneRider View Post
I think so,
Oh, I guess I missed that the first time through.

2006 Red KLR 650

Modifications:
1)Doohickey Planned and purchased 2)Aftermarket Grips 3)Grip Heaters 4)Happy Trails Hard Luggage Rack 5)20 mm ammo cases planned soon 6)Aftermarket Exhaust 7)Thermobob 8)Happy Trails Fork Brace 9)Stainless Steel Oil Filter 10)Magnetic Drain Plug

See profile visitors post for details and planned mods.
steferf is offline  
post #9 of 28 Old 08-07-2012, 05:39 PM
4th Gear
 
Spec's Avatar
 
Join Date: Apr 2010
Location: Gateway to Death Valley!
Posts: 1,928
Quote:
Originally Posted by steferf View Post
I'm not necessary disagreeing with you because I don't know, but what purpose do the multi-cylinder calipers serve then?

Perhaps the multi-cylinder calipers distribute force to larger brake pads more evenly?

Multi-cylinder calipers = bigger brake pads = more contact surface on the rotor = better braking.

No eye has seen, no ear has heard, no mind has conceived what God has prepared for those who love him. 1 Cor 2:9
Spec is offline  
post #10 of 28 Old 08-07-2012, 07:04 PM
Banned
 
Join Date: Jan 2010
Location: Mid-Atlantic
Posts: 763
Quote:
Originally Posted by Spec View Post
Multi-cylinder calipers = bigger brake pads = more contact surface on the rotor = better braking.
Not necessarily, as I understand the situation; depends upon the specific design of a given system.

The force of friction is independent of the contact surface area. Greater suface area may affect brake pad wear, operational temperatures, etc., but . . . does not affect the force of friction, the arresting resistance of the pads on the rotors.

The standard friction equation follows; you'll notice, the area of the contact surfaces is not found in the equation at all:

The following gleaned from Googling, "force of friction equation" on the Internet:

Quote:
Fr = μN

where:

•Fr is the resistive force of friction
•μ is the coefficient of friction for the two surfaces (Greek letter "mu")
•N is the normal or perpendicular force pushing the two objects together

Last edited by LoneRider; 08-07-2012 at 07:13 PM.
LoneRider is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki KLR 650 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Stuck Bolts on Front Brake Caliper Cabron 1987 to 2007 Wrenching & Mods 6 04-27-2017 01:20 PM
1st to 2nd Clunk and piston slap under 3K? AJay112 2008+ KLR650 Wrenching & Mod Questions 9 04-17-2011 06:01 PM
OFFICIAL 18" FRONT RIM UPGRADE THREAD (Part Numbers) Biker Scout 1987 to 2007 Wrenching & Mods 15 10-06-2006 03:24 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome