Honda CBR 600RR Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
5,599 Posts
Discussion Starter #1 (Edited)
Alright, the question didn't get attention in my build thread so here goes,

I just installed CMC rotors along with their complementary Ferodo XRAC pads to replace my OEM setup, after installation it seems the pads of one caliper are making more rotor contact than the other caliper; so there is more drag in one than the other. When I sit on the bike and push it forward there doesn't seem to be too much resistance overall, but there is more drag noise from the problematic caliper. Additionally, when I pull on the rotors (they can move slightly because of the fully floating design) again, the pads that are more restrictive result in very minimal rotor movement compared to the other caliper.

I already bled some fluid out of the problematic caliper but nothing changed.
The brake lever is firm and feels good, brake fluid is just below the upper reservoir mark.

Considering the pads self align, not sure if maybe the restrictive pads simply have more material left in them and therefore are more beefy?

Thoughts.
 

·
Registered
Joined
·
1,430 Posts
Perhaps the pads need time & use to properly bed into the discs?

I've never used cmc's but that would be my initial thought if this situation
 

·
BOTM Winner 04/14
Joined
·
819 Posts
I've seen the post in your build and had no ideas. Reading this thread though, and a thought came up. I am by no means an expert, just having a go :) could the difference in play be due to the dics rather than the calipers? If you remove the calipers, do the discs have the same play?
 

·
Registered
Joined
·
6,774 Posts
probably the pistons in that caliper aren't retracting enough, have you tried popping the pistons out, clean the o-rings & put some silicone grease in to make them slide in/out easier?
 

·
Registered
Joined
·
2,049 Posts
probably the pistons in that caliper aren't retracting enough, have you tried popping the pistons out, clean the o-rings & put some silicone grease in to make them slide in/out easier?
This is solid advice but before I'd even go this far into it, since your bike is a 2011, I'd simply remove some fluid in the reservoir and fully push the caliper Pistons back in to the caliper and use the lever to pump them back out a few times to see if that works them in. Then rebleed and put the correct fluid level back in.

I'd do both sides as well and is something I do on older bikes when I change pads because if you think about your disks, the pad thickness and how far really those picks travel in their "normal" operation it's like 1 mm every time you grab the lever, back and forth that same 2-3mm depending on pad wear gets used.

Exercise them, check their operation and if the wheel spins like it should you're good and stop thinking about it; it's not that unusual for this type of inconsistency to occur between sides, especially since you are listening and looking for it as long as the wheel spins freely.

Mike
 

·
Registered
Joined
·
718 Posts
I'd check your spacers on your wheels as well, just to make sure you put them on the correct sides.
 

·
BOTY 2014 Winner
Joined
·
4,814 Posts
You are being a motorcycle hypochondriac rad...

There is no mechanism to retract the pads from the rotors. When you release pressure on the lever it's not as though they will release. The pad contact discussion has happened here 1000 times because people actively look for issues after doing their own work. Some drag is 100% normal, but nobody checks for it BEFORE they change something.

The cmcs will accentuate the feeling because they are extremely loud. You don't have an issue
 

·
Registered
Joined
·
5,599 Posts
Discussion Starter #8
Perhaps the pads need time & use to properly bed into the discs?

I've never used cmc's but that would be my initial thought if this situation
Both the discs and pads aren't brand new, both of them have been used together before on another bike. Both rotors are almost the same thickness.

I've seen the post in your build and had no ideas. Reading this thread though, and a thought came up. I am by no means an expert, just having a go :) could the difference in play be due to the dics rather than the calipers? If you remove the calipers, do the discs have the same play?
I had that checked, both rotors had the same play in them before I installed them.

probably the pistons in that caliper aren't retracting enough, have you tried popping the pistons out, clean the o-rings & put some silicone grease in to make them slide in/out easier?
I haven't done any of that, all I did was clean the visible piston surface with brake cleaner and a toothbrush, its a 2011 and this is only the 3rd set of pads to ever be installed.

This is solid advice but before I'd even go this far into it, since your bike is a 2011, I'd simply remove some fluid in the reservoir and fully push the caliper Pistons back in to the caliper and use the lever to pump them back out a few times to see if that works them in. Then rebleed and put the correct fluid level back in.

I'd do both sides as well and is something I do on older bikes when I change pads because if you think about your disks, the pad thickness and how far really those picks travel in their "normal" operation it's like 1 mm every time you grab the lever, back and forth that same 2-3mm depending on pad wear gets used.

Exercise them, check their operation and if the wheel spins like it should you're good and stop thinking about it; it's not that unusual for this type of inconsistency to occur between sides, especially since you are listening and looking for it as long as the wheel spins freely.

Mike
Thanks, that sounds like a good plan. will do that.

I'd check your spacers on your wheels as well, just to make sure you put them on the correct sides.
Spacers never left the wheel.

You are being a motorcycle hypochondriac rad...

There is no mechanism to retract the pads from the rotors. When you release pressure on the lever it's not as though they will release. The pad contact discussion has happened here 1000 times because people actively look for issues after doing their own work. Some drag is 100% normal, but nobody checks for it BEFORE they change something.

The cmcs will accentuate the feeling because they are extremely loud. You don't have an issue
Dude, these are bloody CMCs, I got them used and they still cost an arm and a leg, you should know of all people. I just want to make sure everything is proper before I start riding it, especially when this is my first time doing this whole process. I know that there is always a bit of drag to prevent stuff from getting between the friction material and the rotor, and that it is acceptable to an extent, but I want to understand and make sure the discrepancy between calipers is not an issue. Checking before I started wouldn't make a difference since I would be comparing semi-floating OEM Yutakas to the CMCs, completely different as you know.
 

·
Registered
Joined
·
1,430 Posts
Both the discs and pads aren't brand new, both of them have been used together before on another bike. Both rotors are almost the same thickness.
Yes, but the pads could be installed differently from the original bike, could the pads from one side be mixed with the other sides pads?

They may just need a few miles to sort themselves out. I don't know for sure, just throwing ideas out
 

·
BOTY 2014 Winner
Joined
·
4,814 Posts
Rad no need to freak out. Nothing you are going to do is going to change the fact that the pads are going to touch the rotors. The inherent stiction between the seals and pistons will always be there. And it won't always be exactly the same for all 8 pistons. So if you clean and polish over and over all you'll end up with is possibly the other side 'dragging'.

There have been countless threads about EXACTLY this.
 

·
BOTM Winner 03/14
Joined
·
2,497 Posts
Rad I had something like this after I painted my rims. How I fixed my problem was simple. It might be some thing you have already done but I'll say it in case you have not.

When the rim is bolted on the bike loosely. Tie the brake closed then tighten all the bolts for rim and let off brake. It's something that might help.
 

·
Registered
Joined
·
5,599 Posts
Discussion Starter #12
Yes, but the pads could be installed differently from the original bike, could the pads from one side be mixed with the other sides pads?

They may just need a few miles to sort themselves out. I don't know for sure, just throwing ideas out
I have thought of that and your are right, it could be just that, there is no way to know if the pads were mixed, so I'll probably do what Mike suggested and if that doesn't solve it then I'll just go for a ride.

Rad no need to freak out. Nothing you are going to do is going to change the fact that the pads are going to touch the rotors. The inherent stiction between the seals and pistons will always be there. And it won't always be exactly the same for all 8 pistons. So if you clean and polish over and over all you'll end up with is possibly the other side 'dragging'.

There have been countless threads about EXACTLY this.
I'm done cleaning and polishing, I'll follow Mike's suggestion and then ride it. I don't care if there is been countless threads about this.

Rad I had something like this after I painted my rims. How I fixed my problem was simple. It might be some thing you have already done but I'll say it in case you have not.

When the rim is bolted on the bike loosely. Tie the brake closed then tighten all the bolts for rim and let off brake. It's something that might help.
I came across that tip watching one of STG's videos, and plan on trying it once I'm done with the bleeding process. Thanks for mentioning it.

All your input is appreciated, ill report back once I'm done.
 

·
Registered
Joined
·
5,599 Posts
Discussion Starter #13 (Edited)
Well, I tried keeping pressure on the brake lever while tightening the caliper bolts and maybe there's a very slight improvement, anyways it really doesn't seem like there is going to be any excessive drag for now.

Torqued the axle bolt to spec (60Nm), flushed one reservoir of fluid through each caliper, and all should be alright, the lever feels good.

Here's the problem, went for a ride today and there is Massive pulsing throughout the front end when I apply the brakes, even at slow speeds it feels like the rotor is skipping, as in there would be contact with the pads intermittently. I don't know if this is maybe because the pads are not on the specific rotor they were bed on or what, but right now it is almost like the bike is un-rideable. I can't use scouring pads or rotor hones on these CMCs. I'm not sure if it could be steering head bearings either, there was a little mishap during the installation when one of the forks was unsupported for sometime because the platform supporting it caved, but then again when I'm taking a corner the bike doesn't seem unstable or different at all. The only difference comes when I apply the brakes, the harder I apply them the greater the shaking.

When I run my finger on the rotor, there are rougher areas than others, I highly doubt these rotors could be warped from use on a 600cc bike even if it was being raced not to mention I bought them from a trusted individual who checked them before sale.

Thoughts?
 

·
Registered
Joined
·
2,049 Posts
New pads, hopefully clean the old pad material rotor per Wibblys advice and hope for the best.

And know now not to buy used rotors and pads: I've NEVER had good luck doing it and swore it off years ago for the reasons you just experienced; unless they mark the pads to where they go, your fork/wheel/spacer/caliper alignment and operation are EXACTLY the same as the bike it came off of, you're having issues.

No way you hurt your steering bearings by only supporting one fork leg. If they were that fragile how could a bike survive a pothole or God forbid a wheelie?? You're fine there, it's old pad or gunk on the rotor from shipping.

Mike
 

·
Registered
Joined
·
5,093 Posts
i know nada about cmc's////

maybe you have a warped rotor?......a dial indicator will tell the truth.

rotors can be pulled from straight when you mount them.....

sometimes, this can be solved by re installing the rotor and being very careful to evenly torque the rotor into place.


do a 2 stage star pattern torque to final tightness.....
 

·
Registered
Joined
·
5,599 Posts
Discussion Starter #20 (Edited)
Contact Jeff at braketech. There are ways to get the pad material off the rotors
I really hope that is all it is, I found a Braketech PDF talking about potential juddering from pad material. 120Grit sandpaper and finishing it off with acetone. I only have 150 Grit paper right now, so I'll try it out since it's on the softer side of the scale.

New pads, hopefully clean the old pad material rotor per Wibblys advice and hope for the best.

And know now not to buy used rotors and pads: I've NEVER had good luck doing it and swore it off years ago for the reasons you just experienced; unless they mark the pads to where they go, your fork/wheel/spacer/caliper alignment and operation are EXACTLY the same as the bike it came off of, you're having issues.

No way you hurt your steering bearings by only supporting one fork leg. If they were that fragile how could a bike survive a pothole or God forbid a wheelie?? You're fine there, it's old pad or gunk on the rotor from shipping.

Mike
Thanks for the pointers, good to know, appreciated.

i know nada about cmc's////

maybe you have a warped rotor?......a dial indicator will tell the truth.

rotors can be pulled from straight when you mount them.....

sometimes, this can be solved by re installing the rotor and being very careful to evenly torque the rotor into place.


do a 2 stage star pattern torque to final tightness.....
I'll work on the pad material first, then I'll take it from there, but thanks will keep it in mind.
 
1 - 20 of 21 Posts
Top