Author Topic: Front brake discs  (Read 2045 times)

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Bruvex

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Front brake discs
« on: March 28, 2020, 17:42:53 »
Hi all,

Yesterday I wanted to put new brake pads on the front calipers but I noticed both front discs are worn / damaged (?)
On the outside circle of the discs is a noticeable edge on both the inside and the outside of the discs.

It is not that I use the brakes violently or more than often.
I tend to have a smooth and prescient (?) driving style even if I say this myself.
The wheel is turning freely so the pads release properly.

The bike has now 48500klms. This is the firs time I encounter a problem like this.

Anybody any ideas or similar problem?


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superfunkomatic

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Re: Front brake discs
« Reply #1 on: March 28, 2020, 20:05:19 »
Looks like maybe your pads wore unevenly. Is this the first time the pads have been changed on the bike?
Mine were pretty much done around 30,000 kilometres. I think they are an inspection item in the manual every 25,000 kilometres.
New pads will likely just wear with that strange pattern, too.
I know that type of wear can be 'turned' on a lathe for car brakes, I don't think they turn motorcycle rotors (but I'm not 100% sure).
New rotors?
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2016 CRF250L
2008 Varadero (gonzo - one of my favorite bikes)

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SB

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Re: Front brake discs
« Reply #2 on: March 29, 2020, 01:45:06 »
As long as the "active" part of the disk is still within the Honda tolerances (i.e its not too thin) and the new pads don't bind against the raised part I don't see its as a problem.

Bruvex

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Re: Front brake discs
« Reply #3 on: March 29, 2020, 12:27:00 »
Hello,

The pads worn evenly, so no problem there.

The pads were changed the first time at 25k for TWRpads.
They were changed a second time at 39k and now at 48k they are completely worn.
It is noticeable that I have to change them quicker and quicker.

Last evening I met my old dealer (don't tell because not legal at the moment ;)) and he said the discs are worn quite fast in his opinion.
The best thing to do is to mount new discs because mounting new pads is just throwing away money.
He will do it for me and control the brake calipers,... .

I'm talking about my old dealer now because I didn't feel comfortable anymore with the one I bought the bike from.
So I will go for to him for servicing now, as I always did with my former bikes.
The reason I didn't buy the AT at his shop is because he's no longer an official Honda dealer and he's taking on less work because of his age. But since he always had his own racing team for a long time and I never had problems with his work I will return to his shop.
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Prev.:BMuu R1200GS (2009) / Honda Varadero SD02 (end 2003) / Honda VFR 800fi / Yamaha Diversion 900 / Yamaha XJ900 / Honda Shadow 600c

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varonda

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Re: Front brake discs
« Reply #4 on: March 29, 2020, 13:44:52 »
Don't know how true it is but my car mechanic told me that since asbestos has been replace in brake pad material
 discs wear out faster and presumably the same applies to bikes .
If the truth fits---wear it !!!!

superfunkomatic

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Re: Front brake discs
« Reply #5 on: March 29, 2020, 22:26:56 »
I agree that two pad changes in 50,000 seems reasonable but that the wear on the rotors looks excessive.
Could it be a stuck piston in the brake caliper? Is it worn that way on both sides? Might be as simple as a cleaning and lubing of the brake caliper slider.
I'm curious to see what your mechanic decides.
2016 CRF1000L Africa Twin
2016 CRF250L
2008 Varadero (gonzo - one of my favorite bikes)

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Jyrays

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Re: Front brake discs
« Reply #6 on: March 30, 2020, 13:31:42 »
Asbestos has been prohibited in brakes for couple of decades now.

Motorcycle rotors do not have that much extra (due to lighter weight, unsprung masses) as car rotors so usually lathing is not an option.

I would suspect the pads, as you see your wear is increased since you left original pads. I made 34k with the first pads.

As SB says, as long as they are over minimum thickness they can be used.

As you see there is only one mm to use, cars often has even 5 mm.


« Last Edit: March 30, 2020, 13:33:43 by Jyrays »
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zebulon

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Re: Front brake discs
« Reply #7 on: March 30, 2020, 17:20:06 »
As you know grey is gone (I cannot have a look on the disks) but do not remember any mark on them ... I had changed the pads one time 38 500 kms with Brembo ones . no problem at all
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Bruvex

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Re: Front brake discs
« Reply #8 on: April 26, 2020, 14:36:27 »
Ok, new discs (Moto Master (Holland)) are installed.

My dealer 'investigated' the braking system of my bike and he has no 100% answer.

  • the pads (TWR) are very hard and therefor very aggressive for the discs
  • the pads were not sticking to the discs
  • all brake parts worked as they should
  • there was too much brake-oil in the reservoir (probably filled by the former dealer when the pads were already far gone
  • the brakes are completely cleaned now

Probably it was a combination of factors and maybe a lesser quality of the discs that made this happen.

Hopefully I won't have to change them again at another 48k klms.
CRF1000L DCT Silver Grey(2016)

Prev.:BMuu R1200GS (2009) / Honda Varadero SD02 (end 2003) / Honda VFR 800fi / Yamaha Diversion 900 / Yamaha XJ900 / Honda Shadow 600c

VIM 12/13/14/15/16/17/18/19/20

Jyrays

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Re: Front brake discs
« Reply #9 on: May 05, 2020, 14:17:59 »
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