Grooves in Rear Brake Rotor

[walkthejosh]

I searched the board for information on this topic, but couldn't find a mountain of information like I expected. I changed the rear pads and fluid yesterday and noticed considerable grooving on the rear rotor; I can post some photos when I get off work. I'm trying to get a general consensus on what sould be done. I've seen a few people indicate that grooves in the rotor are fine as the pads will simply adjust and I've seen a few say that any grooves requires a new rotor.

[BaltimoreGS]

The term for those grooves is "scoring."  Unlike a rotor on a car, a motorcycle rotor can not be resurfaced.  If the scoring is heavy enough to catch your finger nail in or the rotor is below the minimum thickness spec (usually stamped somewhere on the rotor) it should be replaced.

-Jessie

[slipperymongoose]

I'm with baltimore, even though the rear doesn't see much use you can pick up a new rotor pretty cheap on ebay.

[walkthejosh]

Thanks for the input. I was leaning towards swapping it out since I do actually use the back brake.

On a side note: it's interesting to see the number of people who forgo their back brake completely.

[dropitlow88]

Thanks for the input. I was leaning towards swapping it out since I do actually use the back brake.

On a side note: it's interesting to see the number of people who forgo their back brake completely.

i use my back brake quite often. Especially in slippery/sandy conditions. My sand road is terrible, very soft. Using the front brake could easily upset the bike in soft sand causing a low speed lowside. It's bad enough just trying to ride through it lol

[gsJack]

Thanks for the input. I was leaning towards swapping it out since I do actually use the back brake.

On a side note: it's interesting to see the number of people who forgo their back brake completely.

I'm a big fan of the GS500 rear brake and also of saying "use all three brakes all the time, front, rear, and engine."  I say my GSs have twin discs, one in the front and one in the back.  I grooved my rear rotor rather badly early on my 97 GS and did replace the rotor about half way thru the 80k miles I used the bike.  At first it was hard to tell when the rear brakes loud squeal changed from vibration squeal to metal to metal squeal.     The front and rear rotors on my current 02 GS are original and are getting grooved quite a bit now at 93K miles.  Takes a bit longer to break in new pads with grooved rotors and they then last not quite as long but I've not noticed any loss of braking perforamnce once they are broken in.

http://img.photobucket.com/albums/v443/jcp8832/GSbrakeschains.jpg

[adidasguy]

I depend on the rear brake. Necessary when stopping on all the hills in Seattle. I also use it to slow down a little - like a drag brake.
I keep a supply of rotors and calipers with good pads on the shelf. (I think I have too many now - I'll never go through 6 rotors  )
Your cheapest and in my opinion the best solution is but used calipers and rotors from a new bike with 1000 miles or so that has been crashed. pinwall cycle on ebay always has them. Read the description for the miles and look at the pictures. Usually $14.95 for calipers and $24.95 for rotor. Cheaper than new pads or after market rotors.