Resurface GS Brake Disc Rotors

[KEITH KRAUSE]

You probably already know . . .

Instead of replacing your "wavey" out-of-spec brake disc rotors you may consider having the rotors resurfaced on a rotary surface grinder. This was desirable option for me since I had already cross drilled all three of my brake disc rotors. This resurfacing cannot be performed on newer style floating brake disc rotors. I found this service on Ebay, See Seller: smw70ss (Portland Engine Rebuilders?). I believe they have maintained a 100% Positive feedback to date.


When I received the resurfaced rotor, I checked the flatness by placing the resurfaced rotor on the Inspection surface plate and sweeping a dial indicator over the entire surface. The flatness was within tenths. I checked the parallelism with a micrometer with similar results. Unfortunately I had the service performed last year and the price has been raised to $49.99.

So you had warped rotor(s) had this done, and your brakes work fine? No issues at all such as more lever play or a little loss of stopping power?
Sorry, but what do you mean the flatness is within tenths?
Did you measure your rotor thickness when they came back? This could give you an idea how much they removed. Your factory new thickness is in your manual.
I too have invested in my rotors by drilling them and powdercoating the centers and would be interested in this work if there's no issues related to taking off too much material to get them flat.

[Dirsuper]

Interesting this thread popped up today. I have a 1982 Suzuki GS 1100 L (GLZ). The front brake pads are worn so I went to a shop today to buy new pads. Given that I now replace the rotors on my cars when I replace the pads (super cheap), I asked for same. WOW! The rotors are $220 each, I later found them for $145/each on JCWhitney.....still, that is a lot of cash. I have no reason to think they are warped, and there does not appear to be any serious grooving. I was just thinking of using some brake cleaner to clean them really well and then hitting them with some really fine sandpaper. Any thoughts. Obviously front brakes are vital, but I just cannot justify spending $500 on new rotors if I can salvage the old ones. Any gouge/experience in this area is greatly appreciated.

Thanks,
Mike

[Mysuzyq]

If you have a micrometer or vernier calipers measure the thickness to see if they are within the manual's service limits....if they are, and not warped (no 'pulsing' at the lever, when brake is applied) re-use them.....if not, get a set on ebay.... they are the same slotted rotors used on the E, and other bikes, I think. Be sure to ask about thickness/flatness before pulling the trigger though. New pads feel weak for the first few miles on old rotors, before bedding in.
Tony.

[posplayr]

If anyone is interested

http://www.thegsresources.com/_forum/showthread.php?p=1124104#post1124104

[srsupertrap]

So you had warped rotor(s) had this done, and your brakes work fine? No issues at all such as more lever play or a little loss of stopping power?
Sorry, but what do you mean the flatness is within tenths?
Did you measure your rotor thickness when they came back? This could give you an idea how much they removed. Your factory new thickness is in your manual.
I too have invested in my rotors by drilling them and powdercoating the centers and would be interested in this work if there's no issues related to taking off too much material to get them flat.

I did the rear disc in 2006 and when I received it I measured it with my Mituyo digital caliper. It was well within Suzuki's upper tolerance specification although I don't recall the exact measurement anymore. The Portland Shop took off the bear minimum of material which probably explains his 100% rating; he appears to have his process down. I have experienced no negative brake issues such as more lever play or any loss of stopping power.

Ten-Thousandths (tenths) is .0001" Flatness is a measure to itself. Some people mistake Parrallelism for flatness. I measured the flatness by placing the resurfaced rotor on three 1-2-3 Blocks placed on a surface plate and sweept the entire bottom surface with a dial indicator. The worst run out was .0007" and I measured it several times and got repeatable results.

The resurfacing is probably a good choice for you because your reasons are the same as mine were.

[KEITH KRAUSE]

OK Thanks. The rear is quite a bit thicker than the fronts. More to play with.
I want to do the fronts. Hopefully there's no issues due to how thin they are to begin with.

[Nessism]

OK Thanks. The rear is quite a bit thicker than the fronts. More to play with.
I want to do the fronts. Hopefully there's no issues due to how thin they are to begin with.

The rotors on the round puck brake pad bikes are quite thick. I'm pretty sure there wouldn't be any worry even if you were under the factory spec. The later rotors, starting in 1980, in comparison are a fair bit thinner to begin with so I wouldn't take those under.

BTW, the later calipers are better in terms of controlling brake squeal, but those early calipers are plenty durable since they have bronze bushings on the pivot pins.

[srsupertrap]

OK Thanks. The rear is quite a bit thicker than the fronts. More to play with.
I want to do the fronts. Hopefully there's no issues due to how thin they are to begin with.

It's a good winter project and one you won't regret. It might be cheaper to find a used set but when you owned your GS for three decades an extra fifty doesn't much matter if you know what I mean

[KEITH KRAUSE]

Oh I do know what you mean. Nothing's too good for my girl.

[Flaggo60]

....get a set on ebay.... they are the same slotted rotors used on the E, and other bikes, I think. Be sure to ask about thickness/flatness before pulling the trigger though....

Exactly. I got a nearly new pair of front rotors for my 650 with very little wear on EBay for $15 plus shipping. They´re on and they´re great.

[Shin-Ken 1074]

As my GSX1100 is THE keeper I have had to address the issue of worn rotors and what to do about them. I had the three worn rotors skimmed and luck was on my side as they were within run-out specification this time, but they wouldn't make it for another resurface. Rather than chase up used rotors and the problems that can arise with them I bought a set of new genuine rotors to hold down papers and other things in the shed until they need to be fitted. Though not cheap I prefer to have brakes that work well and I figure the spare rotors once fitted should keep the GSX on the road for another 25 years, ha ha ha, yeah if dino lizard fuel is still affordable by then.