| Author |
Message |
    
B2tomtom
| | Posted on Wednesday, January 01, 2014 - 11:18 pm: | 
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Here is a pic of the chatter marks.
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Dhays1775
| | Posted on Wednesday, January 01, 2014 - 11:25 pm: |
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B2, would it be a possibility that the pads don't get hot enough when you use them (not braking hard enough)?
Not saying that's the reason, just a possibility...
Also, did you rebuild the caliper? It may be that the pistons aren't pushing the pads out evenly. Again, just a possibility. |
B2tomtom
| | Posted on Wednesday, January 01, 2014 - 11:29 pm: |
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Its definitely a possibility. I ran the bike up to 80 and grabbed the brakes hard a couple of times to see if that would clean it but didn't seem to change. I didn't rebuild the caliper when I changed everything out. Never had an issue like this before I changed everything. I sent a message to EBR along with the pics to see if they have any ideas. |
Jdugger
| | Posted on Thursday, January 02, 2014 - 01:07 pm: |
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When you replace the rotor, replace the pads, too. That's why you got "chatter" |
B2tomtom
| | Posted on Thursday, January 02, 2014 - 01:17 pm: |
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@Jim The pads are brand new 2015's. Is there a special break in procedure for them? When I get home today I am going to lift the front end and verify everything is true. I checked the old rotor on a granite measuring table and it was still true. |
B2tomtom
| | Posted on Thursday, January 02, 2014 - 09:47 pm: |
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To recap the situation, I installed a new EBR rotor, EBR mounting hardware and EBR 2015 pads. On the first ride I noticed that the bike surged when on the brakes and saw the chatter marks on the rotor.
Put a dial indicator on the outside bead of the rim and it ran out at .020". Also put it on the outer perimeter of the rotor and it showed .010". As far as the chatter marks when I had the indicator on it the rotor shows a series of .003" waves in it that coincide with the dark marks.
I pulled the rim and all the pistons move freely on the caliper so I am cleaning it up and will reassemble everything. I'll go for another test ride and try to heat them up to see if the chatter marks disappear and also see if the surging is still present. |
B2tomtom
| | Posted on Friday, January 03, 2014 - 01:07 am: |
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Took it a little further on reassembly. Removed the rotor and used the dial indicator on the mounting pads, found 2 of them adjacent to each other that were .005" and .006" low compared to the others. So we made up some shims and installed them under the copper washer. Got the run out on the rotor down to .003". Test ride in the morning. |
Glide
| | Posted on Friday, January 03, 2014 - 08:04 am: |
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Bead blast or sand your rotor, looks like build up from your old pads. This needs to be done every time you change the pads, it will act all most like a warped rotor. |
B2tomtom
| | Posted on Friday, January 03, 2014 - 09:18 am: |
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@Glide- the rotor is brand new and only has 90 miles on it with a new set of pads. |
Dhays1775
| | Posted on Friday, January 03, 2014 - 09:19 am: |
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Glide, he ever used his old pads with the new rotor. That's why it's so strange.
B2, I hope the shims you made work out. The only problem I see might be that the runout now might cause a feeling of the rotor "wobbling" inside the caliper. |
B2tomtom
| | Posted on Friday, January 03, 2014 - 09:46 am: |
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David, I hope they work out also. Bill and I spent a few hours last night and were happy to cut the run out in half. Interesting thing is that it all happens around 1 fastener now. Its .001" high on one side, right on at the fastener, and .002" low on the other side. |
Dhays1775
| | Posted on Friday, January 03, 2014 - 09:52 am: |
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That's pretty wild.
I'm sure you already checked, but is the new rotor true?
It just seems like a lot of work to fix something that shouldn't be broken.
 |
Jdugger
| | Posted on Friday, January 03, 2014 - 09:55 am: |
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It's likely the wheel is not true. The Buell cast wheels are not high quality, and there's a lot of variance among them.
Not unusual to need to have the rotor mount points machined true. |
B2tomtom
| | Posted on Friday, January 03, 2014 - 10:01 am: |
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Jim, we checked all of the rotor mount pads 4 were the same and 2 were .006 low so we put some shim stock under those copper washers to see if it fixes the problem. If it comes down to it I can take it to a friends machine shop and get them machined true. Thanks for the advice. |
B2tomtom
| | Posted on Friday, January 03, 2014 - 10:03 am: |
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David, the rotor seems to be true. The low spots were both at the fasteners with low mounting pads. |
B2tomtom
| | Posted on Friday, January 03, 2014 - 11:53 am: |
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Took her out for a ride this morning and the surging has practically gone away. The shimming seems to be the cure. As far as the chatter marks go I have been talking with the techs at EBR who have been very fast in response times and the say that this pattern is normal and they have seen it on the 1190RS and other track bikes. Did a couple of hard stops and the chatter marks are getting smaller. I am going to be making up a dozen sets of the laminated aluminum shims in case any one needs some in the future. |
Jdugger
| | Posted on Friday, January 03, 2014 - 07:42 pm: |
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> The shimming seems to be the cure.
Depends on how you did it. If you used copper washers, the drawback is they will crush over time and fall back out of alignment. Spring steel or stainless work well, but reduce some of the heat transfer that makes the new mounting hardware better for racing. |
