Rotor Resurfacing vs New Rotors

[Widowmaker]

My rear rotor on my 1998 ST1100 ABS/TCS II is worn a bit a slightly rough to the touch. I let the pads get ground down to the metal. I'm struggling to find good aftermarket rotor options, as the OEM part for the rear rotor was only built for this particular model, years 96-2002. I'm considering taking it to get resurfaced, I have access to digital calipers at work but have not measured the thickness on it yet. Any thoughts?

 

[Bush]

If you can find someone who can surface grind it and it will still be in spec, then why not?

 

[Upt' North]

I think you'll be pushing your luck on thickness, but the gauge won't lie.
Also check closely for signs of cracking around the mount holes, my 98 was replaced by an OEM about 3 years ago with suspected hairline fractures. I think I paid about £100.00 from Silvers.
Upt'North.

 

[fnmag]

I'd go ahead and get it resurfaced, assuming it's thick enough.

 

[SMSW]

You have to weigh the cost of resurfacing to replacing it with an aftermarket or a used one from eBay. If there is enough steel there to do two cuts (both sides) and you have the equipment, go for it.

My manual for a ST 1300 shows Service Limits: Front - 4.0 mm (0.16 in) Rear - 6.0 mm (0.24 in) and a max warp of Front: 0.20 mm (.008 in); Rear - 0.30 mm (0.012 in). It does not say what the new thickness is.

 

[beemerphile]

The new pads will pretty quickly wear into the grind marks. You will have somewhat reduced braking power until it does. I would just run it. Especially on the rear, as 80% of your braking power is on the front. If you grind it, you are grinding away rotor life and any metal you take off makes it run that much hotter. As long as the grooves are circumferential and not radial, it won't make noise or produce vibration.

 

[sirepair]

IIRC GL1500 rear rotors will interchange, but you should check 1st.

I'm w/beemerphile on this one; slap in some new pads and ride!

 

[GGely]

+1 on Beemerphiles suggestion.

In my case, I picked up an EBC MD1077 rear rotor as part of a set from a parted out 99 ST1100. Checked on the EBC website and yes, it fits the GL1500 as well.

Here’s an excerpt from their catalogue:

 

[Larry Fine]

My manual for a ST 1300 shows Service Limits: Front - 4.0 mm (0.16 in) Rear - 6.0 mm (0.24 in) and a max warp of Front: 0.20 mm (.008 in); Rear - 0.30 mm (0.012 in). It does not say what the new thickness is.

Every rotor I've checked barely met new specs when new.

 

[paulcb]

Without seeing how bad it is and it doesn't sound bad at all, I'd err on the side of Beemerphile... just throw new pads in there. Although, while you're in there, clean everything, especially the pistons. A shoelace dipped in brake fluid works pretty well. If the fluid hasn't been changed in a few years or if it's not somewhat clear, now would be a good time to flush it.

 

[Bmacleod]

The new pads will pretty quickly wear into the grind marks. You will have somewhat reduced braking power until it does. I would just run it. Especially on the rear, as 80% of your braking power is on the front. If you grind it, you are grinding away rotor life and any metal you take off makes it run that much hotter. As long as the grooves are circumferential and not radial, it won't make noise or produce vibration.

I would agree with this, to a point. I would suggest removing the rotor to inspect it for cracks and also for minimum thickness. If you wore it down below spec with the metal-to-metal running, i would still replace it

 

[Uncle Phil]

If ain't cracked, new pads and ride!

 

[Widowmaker]

Without seeing how bad it is and it doesn't sound bad at all, I'd err on the side of Beemerphile... just throw new pads in there. Although, while you're in there, clean everything, especially the pistons. A shoelace dipped in brake fluid works pretty well. If the fluid hasn't been changed in a few years or if it's not somewhat clear, now would be a good time to flush it.

Thank you for the reply, I ordered a set of ceramic pads, and I'll just go ahead an rebuild the entire braking system and keep the stock rotors, I'm going to measure the rotors during my break today, I'll post the results.

Also, I had another thread going about SS lines, I've rebuilt and put SS lines on every bike I've owned except the ST, but I'm convinced it'll be worth it.

 

[Kevcules]

If you have your rotors off the bike and know someone who can turn them for not much money, I would have him take a light skim off them. Not true them up perfectly ,as that may take too much material off. The newly skimmed rotor surface will grab much better, better braking. If you're close to the min limit, change them and be done with it for many more miles.

 

[Widowmaker]

Every rotor I've checked barely met new specs when new.

I measured 0.19" on the front, 0.29" on the rear

 

[beemerphile]

 

[wjbertrand]

I wanted to re-surface some motorcycle rotors a while back and couldn't find a shop willing to try it. In the end I was able to get Honda to cover them under warranty.

 

[GGely]

Also, I had another thread going about SS lines, I've rebuilt and put SS lines on every bike I've owned except the ST, but I'm convinced it'll be worth it.

Installing the SS clutch line the other day brings my SS total to 4 on my ST. Having ridden it back to back as I installed each set, I continue to believe it’s the way to go on any bike. Big improvement for every bike I’ve put them on.

 

[dwalby]

Hello Gents.
So, what does Honda say the thickness of a 2003 ST rear rotor should be? Front as well.
BeWell; M

I'm pretty sure the 1300 rotors are the same spec as the 1100 rotors, based on the wear limits mentioned in post #5 of this thread. If so, the fronts are 5.0mm new 4.00mm wear limit and the rears are 7.5mm new, 6.00mm wear limit.

 

[CYYJ]

...I had another thread going about SS lines, I've rebuilt and put SS lines on every bike I've owned except the ST, but I'm convinced it'll be worth it.

I'm not sure you have the spending priorities in the right order. If you want optimum braking performance, and you have concerns about the condition of the disc on the rear wheel, I think you would get a bigger bang for your buck by replacing the rear disc with a new one. In other words, if I had to choose between a new disc and stainless steel brake lines, I think I would buy the disc first.

I'm sure that stainless steel brake lines offer some advantages over OEM ones, but if you can lock up the wheels (make the ABS system activate) using the existing OEM brake lines, what's the point of gilding the lily by installing stainless steel lines?

Michael