CB650F Warping front rotors

Itchytoe

2018
CB650F
Dec 15, 2019
I've had my 2018 CB650F for about a year now. It was old stock when I got it so I got a pretty good deal. Not long after I got it, I managed to mess up the front rotor due to a very unfortunate encounter with a deer. Got everything fixed and all was good for another few thousand miles, but as of late, I've noticed a pulsation from the front brakes that gets worse the harder I use them. Clearly, I've managed to warp the rotors again. Not sure how, but I did. I need to replace them, but don't really want to use the stock ones again because they didn't last too long. Is there a common front rotor and pad upgrade for the CB650F that I should look for, or do the stock rotors normally work well?
 

miweber929

2014
CBR650F
650F Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Most have no issues, but baugustine @baugustine replaced his do to noise he couldn’t make go away. I think he did EBC.

They may be warped (not sure of the “again” statement unless they warped after the deer hit and not bent) again, but that’s not typical thing to have happen.

Just to add, these are solid mounted disks, they have no floating capabilities like most do so any imperfection will be amplified.
 
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baugustine

2014
CBR650F
Staff
May 21, 2016
Ventura, CA
To follow up on miweber929 @miweber929 s assessment above, I was having noise issues at low speed braking. I replaced the pads with EBCs, no change, ended up replacing the rotors with Galfers. Noise went away until recently, now its back, although less. Rotors are most likely glazed, even with a different pad. It must be environmental (either weather or me).

My point is warping rotors takes an insane amount of heat. These are not like car/truck, where you are bringing 4500 lbs to a stop. These bikes are 450 + rider. If you were doing lap after lap on a track, I could see warping them, but not normal street riding. IF they are actually warped, either the pins are not lubricated on the caliper and the pads are making constant contact (ie never cooling off) or you are panic braking all the time (which I doubt). Check the wheel balance as well as bearings for wear
 

Itchytoe

2018
CB650F
Dec 15, 2019
I had them replaced at a Honda Powersports dealer after the deer incident. I assume they lubricated everything that needed it. I'm definitely not panic braking all the time. In fact, I consider myself easy on the front brakes. Most stops are just engine braking and a little rear brake to finish the stop. miweber929 @miweber929 You're right, again isn't the right word. They were bent after the deer encounter, not warped. I might need to take things apart and make sure it's all lubricated and maybe hit the rotors with a light sandpaper to make sure they aren't just glazed.
 

Itchytoe

2018
CB650F
Dec 15, 2019
Maybe more damage from the deer than you thought? Maybe a bent rim? Is it just the brakes or is the bike shimmying?
Nope, no shimmy at all up to the triple digits. The bike rides nice and smooth at every speed I've tried. I've put about 10,000 miles on the bike since the deer encounter. Everything was nice and smooth when I first got the rotors replaced. They've slowly been getting worse and worse. I don't notice it with very light brake pressure. I notice it more the harder I get on the brakes.
 

Devilsfan

2018
CB650F
Jun 5, 2019
Tampa, Florida
Nope, no shimmy at all up to the triple digits. The bike rides nice and smooth at every speed I've tried. I've put about 10,000 miles on the bike since the deer encounter. Everything was nice and smooth when I first got the rotors replaced. They've slowly been getting worse and worse. I don't notice it with very light brake pressure. I notice it more the harder I get on the brakes.

OK, so I would look at the brakes first, like baugustine said, before you go out and throw down extra $$$ on a new rotor. Could just be the brake pads or maybe something's not aligned on the calipers, etc.. I'd start there first.
Also, after pulling off the calipers, pull out the wheel and take the rotor off to check. You may be surprised it's not the rotor at all.

The positive...should be an easy fix with not much money having to be spent!!!
 

miweber929

2014
CBR650F
650F Alumnus
Staff
Feb 13, 2015
Woodbury, MN
Nope, no shimmy at all up to the triple digits. The bike rides nice and smooth at every speed I've tried. I've put about 10,000 miles on the bike since the deer encounter. Everything was nice and smooth when I first got the rotors replaced. They've slowly been getting worse and worse. I don't notice it with very light brake pressure. I notice it more the harder I get on the brakes.
Yeah, with 10K since the deer encounter I’d start with the calipers being sure the pistons retract and extend correctly and that the brake pins, both the sliders and pad pins, are smooth and slide freely. How old is your fluid as well?

Definitely could be rotors, and a sanding and cleaning them should help but it may be other things.
 
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