Warped discs

[Banksy]

Just posting to see if anyone else here has or is having issues with front discs warping?

Had my bike since March.. By June the front discs had warped with about 3k on them... New set of O.E fitted under warranty..Just had the bike serviced today (6K) with 6900 miles showing and been told the discs are warped slightly again, may not be covered again under warranty.?

Anyone else have issues with their discs?

 

[flydnb]

they should be covered mate , pads wont be but discs should for the full two years, is yours an abs by the way?

 

[Banksy]

Yep, ABS... forgot to say..

 

[flydnb]

is the dealer a premier Yamaha dealer as they should be looking into why the discs are warping, must be something causing it other than the discs themselves.

 

[misscrabstick]

The dealer needs to get the dial gauge out and check the wheel for runout where the discs mount to the wheel hub, the wheel bearings need to be checked for slop, the calipers need to be checked for free movement, I have not heard of anyone else suffering from this so far, how did the fault manifest itself the first time? usually one would expect some juddering from the front end and a pulsing movement of the lever under braking, note though that I believe some lever pulse is usual if the ABS is operating during a skid situation. Yamaha should have spec's in the MT manual for permissable disc run out, I wouldn't be too surprised if some workshops contained techs who don't even understand how to check disc runout.

 

[Banksy]

It started the first time as the sensation of the disc binding in one spot under light braking from about 10mph or less.. Didn't feel any pulsing at the lever at any speed. At more than about 10mph brakes felt normal.
Getting the same feeling again now just not as bad yet.

 

[Kinjane]

If the discs are hot and you continue to apply the brakes after coming to a stop, the heat transfer through the pads and calipers can cause warpage because of the uneven rotor cooling
- especially with the thinner ones found on the MT.

 

[Fireblade Refugee]

It started the first time as the sensation of the disc binding in one spot under light braking from about 10mph or less.. Didn't feel any pulsing at the lever at any speed. At more than about 10mph brakes felt normal.
Getting the same feeling again now just not as bad yet.

This sounds like what's happened when I've put a bike away wet left for a week, some rust has built up on the disks where moisture was trapped between the pads and the disk. Simple fix - accelerate to high speed, then brake hard. Repeat as necessary.

What Kinjane has written above is the other possible cause, however if this was the case you'd feel it through the bars when braking harder at higher speeds.

 

[motorcycleboy]

It started the first time as the sensation of the disc binding in one spot under light braking from about 10mph or less.. Didn't feel any pulsing at the lever at any speed. At more than about 10mph brakes felt normal.
Getting the same feeling again now just not as bad yet.

This feeling is common when the discs are new.
It will dissapear after several thousand miles.