New Brake Pads?

Derry Walsh · 12-30-2002, 01:41 PM

I just picked up some new stock BMW brake pads. The part number on the old pads is: 07.4901.12. The new pads that I just picked up are :07.4901.14. There appears to be a date on the pads of 11/00 and 03/02 respectively.
What concerns me is that the new pads are "beveled" on the ends. That is there will be less pad in contact with the disk. Substantially less, perhaps 8 to ten millimeters on each end. Over time however, because of these tapered ends, the pad length will effectively become longer.
What’s up?

repoe3 · 12-30-2002, 03:08 PM

sounds like it gives the pad the ability to increase the surface area while it wears so to compensate for any increased force applied to get equal braking that one usually has to apply new the end of brake pads. but then again i just ride them and change the parts as the need arises.
repoe3

MarkC · 12-31-2002, 01:03 AM

Sounds like the same pads I got from the German dealer (for Brembo front calipers) , with the contact surface of the pad being about 3/4 of the area normal pads would touch. I find them acceptable for touring and normal (speed limit obeying) riding, but for track riding they performed poorly (from my experience). They heat up quickly, glaze over, blue the rotor and cause the lever to go soft (large circuits where speeds are high). I installed them right before a 2,000km Alps tour (meaning lots of braking), so I'm certain they were well bedded in before I headed to the track (from my experience, a common cause of glazing is when new pads aren't fully bedded in before hard use). Simple solution is to sand the glaze off the pads and clean out the groves with a sharp pick (bed them in again), and not use them for aggressive braking. I plan on replacing these with EBC Sintered pads before I do another track day, but again for street riding they are fine.

I suspect the reason they are beveled is to decrease brake pad rattle/squeal/noises as the pad begins to touch the rotor. I remember seeing mechanics doing this to new pads for bikes and cars (bevel the edges) to help prevent brake squeal/noises.

MarkC

Dave Hopkins · 12-31-2002, 09:36 AM

I will second everything Mark said, bevel is to minimize squealling. Standard BMW lining is very prone to glazing, I have sanded them and taken Scotch Bright to the rotors to put a slight texture on them to get them to re-seat. Best thing is to trow them and replace with a good aftermarket pad. While I can't claim to have tried them all I am a fan of Galfer's "Green" lining! Very strong, no glazing, rotors stay nice!