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Main Area => General GS500 Discussion => Topic started by: smokedogg on February 27, 2009, 03:58:00 AM

Title: Minor Warp in Disc
Post by: smokedogg on February 27, 2009, 03:58:00 AM
Hi,

Well back to my GS500 '95.

I just bought EBC brake discs to both front and rear.
After re-installing front wheel with the new disc, I notice there is a slight pulse in the disc when rotating the wheel. It is almost not visible, but still.
How much is acceptable if any? Can the caliber compensate for this minor pulse or?

BR
Allan


Title: Re: Minor Warp in Disc
Post by: Affschnozel on February 27, 2009, 04:08:00 AM
Max runout is 0.3mm according to manual for front and rear disc , mount everything up pulsate the brake couple of times and spin

the front wheel,see if the disc rubs on the pads
Title: Re: Minor Warp in Disc
Post by: Jackstand Johnny on February 27, 2009, 04:12:21 AM
I think Ive got a problem with my EBC fron t rotor too. Ive had it since I got the bike(PO install), but recently it makes the bikes front end dive a little over and over when I brake with a little force.
Title: Re: Minor Warp in Disc
Post by: bill14224 on February 28, 2009, 01:32:00 PM
If your brake is pulsing, the disc is warped and/or you have bad wheel bearings.  But, if you have one or two bad bearings, you'd know it.  I also just replaced my front brakes and my discs are original and still true. ('94, 18,000 miles)  As far as I know, there's no such thing as a minor disc warp.  You're only going to ruin your new pads, waste fuel, and have a dangerous condition until you replace it.  You may have to grab the brakes hard in the near future, and warp the disc more which may prevent you from getting home.  Time for a new rotor, and check and re-grease those wheel bearings while you're at it.
Title: Re: Minor Warp in Disc
Post by: joshr08 on February 28, 2009, 01:35:26 PM
i think you missed the part where he said he just put new rotors on front and back.  I would call where ever you bought them from and tell them they sent you a bad rotor dont drive with it otherwise they will most likely say you warped it with your driving/braking style.
Title: Re: Minor Warp in Disc
Post by: GeeP on February 28, 2009, 01:47:05 PM
Give the bike a ride and see how it does.  The disc may align itself, as the bobbins allow the rotor to move on the carrier slightly for heat expansion reasons.

If the brakes are smooth with no pulsing, you're fine.  Forget about it.



If they pulse and the rotor still shows runout...

Did you Scotch Brite the area under the mounting bolts before bolting down the new rotor? 

ANY amount of corrosion or crap under there will cause the rotor to move out of plane with the wheel rotation.

Failing that, go to a machine shop and ask them to put your rotor on their surface plate (a flat reference surface made of granite).  Tell them you're not sure if your rotor is flat or not.  If it isn't flat, ask them to slide some feeler gauges under it to determine how much it is warped.  Then, take it up with EBC.