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Hello, first timer so be gentle! I Have a 2019 ZX10R KRT Performance and since new it has had a a brake judder. Very low speed, below 10mph like slowing to a stop with only single finger pressure, I get what I can only describe as a purr through the head end. Dealer has changed the pads, checked the discs and everything to ensure everything is tight around the headend. There’s no pissy cats installed. They are bemused. Hard to describe as it’s not in any way coming through the bar ends. Has anyone experienced anything like this on a new zx10r? Dealer is now in fob off mode so need to get real help. It doesn’t prevent the bike being fully enjoyed but as an engineer of sorts would like to know what’s going on. Thanks
 

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Has the dealer tested the rotor for runout with a dial indicator? If not, this should be done to eliminate runout as a possible cause. Even if they claim to have done this check, I would verify by doing it myself.

Does your bike have ABS? If so, try disabling ABS to see if the problem goes away.
 

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Discussion Starter #3
Has the dealer tested the rotor for runout with a dial indicator? If not, this should be done to eliminate runout as a possible cause. Even if they claim to have done this check, I would verify by doing it myself.

Does your bike have ABS? If so, try disabling ABS to see if the problem goes away.
DTI test done with no issues. It really doesn’t seem to be the usual brake judder from discs or pads. I haven’t tried switching off ABS so I will try that over the next few days. Thanks
 

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DTI test done with no issues. It really doesn’t seem to be the usual brake judder from discs or pads. I haven’t tried switching off ABS so I will try that over the next few days. Thanks
Can you give us an idea of the frequency of the judder? IE how many pulses per second at a given speed.
I assume the frequency corresponds directly to your speed, so what is frequency at say 10 MPH?
 

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Discussion Starter #5
Can you give us an idea of the frequency of the judder? IE how many pulses per second at a given speed.
I assume the frequency corresponds directly to your speed, so what is frequency at say 10 MPH?
Only happens at very low speed, literally as you come to a stop under minimal braking effort. Does not happen at any other speed or heavy breaking. Very rapid pulse for a second or two. It’s hard to describe it. My initial thought was electrical signal of some sort again dealer dismissed due to no fault codes on ABS or any other system. If I can get out on her over the next few days I will attempt to video it. Dealer mechanics hadn’t seen any like before! It’s going back for its first service end of the month so will be pressing for a deeper investigation
 

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This is a common complaint when dual front discs that have ventilation holes in them. At slowing speed, right before coming to a stop, it feels like very rapid ABS engagement, 2 or 3 times faster than ABS pulse though. Perfectly normal.
 

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yeah it sounds normal. It's a race bike in street trim, meaning certain things are designed to work more from a high performance standpoint and less of a "comfortable" standpoint, and the brakes are one of those. The arguement was (at least for us) "well it's got ABS that means it's good for street use". Well, ABS is also a very good track feature, particularly on a liter bike, just like traction control. Traction control should be mandatory on a well-ridden liter track bike.

I was originally thinking that the pads were contaminated with the cosmoline that they coat the rotors with during shipping/crating/assembly but since the pads were already changed, that kind of rules out contamination (unless you have a leaking fork leg or something allowing some fluid to get on the rotors). Many a dealer fails to properly remove the shipping coatings on the rotors, which means removing the calipers from the rotors, wiping the rotors with a clean white cloth until the cloth no longer picks up any darkening from the wiping process. Then comes the fun part, cleaning each of the vent holes, rifle cleaning kit works good but I like to use brake cleaner instead of power solvent. White bore cloth. Each hole until it stays clean. Tedious. Guys don't like to do it because it's tedious and takes time, and most of the time the new bike owner is waiting impatiently to get his bike while the dealer tech is trying to properly do a PDI. That's what I hated about working on bikes. One of many things actually.
 

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Cookie monster is correct regarding failure of dealers to clean rotors. When I started as a professional motorcycle mechanic I was lucky enough to have an owner who wanted everything right. This included taking the carbs off every motorcycle that was uncrated. We would remove the carbs, disassemble, clean, check float level and reinstall. Timing was also checked. These steps are unheard of today. Rotor cleaning was performed during assembly. I do however disagree with the statement about ABS. I have been riding for fifty years, owned approximately 35 motorcycle and 35 cars. Raced MX in the seventies, road raced from 2003 to 2005, with autos have competed in auto cross and HPDE/ time attack. I hate electronic driver aids. I will readily concede that they are likely to save many lives but at the track I want to see pure talent. I do not want to see rider/driver mistakes saved by some engineer's software. If I make a mistake and run off track, well then I learned something.
 

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I would like to add that in 2005 I bought a Ducati, two large front rotors with twin four piston calipers. Had a car pull out in front of me at what seemed an impossible situation to save. As I was road racing at the time my braking skills were quick and efficient. Went to full front brake, rear tire chirping over ripples in the road, nearly 100 percent weight transfer. I was able to stop before hitting the car. Most riders do not practice or even appreciate the capabilities of the front brake.
 

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Discussion Starter #12
Thanks for all the info. It appears disc alignment check wasn’t carried out correctly first time around. 0.04mm LH & 0.11mm RH out of alignment. Kawasaki paid for replacement discs and pads. Haven’t had chance to give it a full test yet but I’m not 100% convinced from the ride home. But happy nothing major is wrong.
 
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