Hawk front brake oscillation

Ac21 · 08-25-2018, 04:10 PM

When I brake on my hawk (front) I get this bad oscillation like the rotor is warped, seems to be getting worse. I don't have a dial indicator but a "spin test" doesn't show much but I do see a seal that appears to be not sitting evenly. I have a video that shows the seal and rotor.

Also you can hear the pads and rotor rubbing.

Lit Hawk · 08-25-2018, 06:51 PM

Looks like your bearings aren’t seated in evenly. I’d replace them with better ones than the stock. Front wheel bearings:6301-2RS

Ac21 · 08-25-2018, 09:46 PM

How can you tell?

Cravin01 · 08-25-2018, 10:04 PM

How many miles is on your bike? I don't hear a real issue yet but I ride till it's more obvious, a little pad rub on a free wheel is normal on break in.

mine rubbed out of the gate new, I looked it over made sure I everything was in proper place and have taken the wheel off a few times and it now is all good.

I too checked the the disk to see if it was not straight. Seems the more miles I put on it the better it gets.

Are you getting a pulsing feel when applying the brake? If so ..not good.

also grab the wheel and see if there is any play while its jack up off the ground and be forceful to simulate the weight of the bike and force it can create. Bad bearings if so. With no weight on it the wheel seems to roll true.

Make sure you are snug on the axle bolt so you don't get side to side slop.

Ac21 · 08-25-2018, 11:15 PM

It has about 700 miles. I wasn't very clear on the issue on the first post but pulsing feel when applying the brake is the issue it feels like it's getting worse, if I apply only front brake you can see the bike front suspension moving up and down.

ChrisWNY · 08-26-2018, 01:26 PM

I feel a slight pulse with my front brake rotor as well (I feel the pulse in the brake handle itself, not anywhere else). I chalked it up to the rotor not being completely true but it doesn't seem to affect braking performance all that much so I've just rolled with it that way. Despite the pulsing, the brake pad wear seems pretty good and the surface of the rotor appears to be just fine.

If applying the front brake is causing your suspension to go up and down, that sounds like it could be an entirely different issue, not just the true'ness of the rotor. Have you checked to make sure your brake pads are wearing evenly and is the surface of your rotor gouged or scratched up?

kirkallen143 · 08-26-2018, 03:28 PM

Did you clean the rotor and pads off with brake cleaner? They come shipped with an oil protectant of some sort. Same with the rear.

Kirk

Ac21 · 08-26-2018, 07:32 PM

The rotor surface looks good, I haven't checked the pads for even wear. I didn't clean the pads and rotor when I first got it so it may be that protection material on the rotor but now probably too late to clean off.

Azhule · 08-26-2018, 09:26 PM

You can still clean them up, just takes some elbow grease with that Brake Cleaner spray

I usually go with Super Tech Brake Cleaner from Walmart... sure a few other "name" brands will clean a little better... but is it really worth the 4 - 7$ premium paying for a name?!?

And if you are worried about "name brands"... just take a peek at the MSDS on the Super Tech Brake Cleaner, you will find out it is made by a well known chemical/oil company anyway

08-25-2018, 04:10 PM	#1
Ac21 Join Date: Jun 2018 Posts: 54	Hawk front brake oscillation When I brake on my hawk (front) I get this bad oscillation like the rotor is warped, seems to be getting worse. I don't have a dial indicator but a "spin test" doesn't show much but I do see a seal that appears to be not sitting evenly. I have a video that shows the seal and rotor. Also you can hear the pads and rotor rubbing.
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08-25-2018, 10:04 PM	#4
Cravin01 Join Date: Jan 2018 Location: Forney Texas Posts: 498	How many miles is on your bike? I don't hear a real issue yet but I ride till it's more obvious, a little pad rub on a free wheel is normal on break in. mine rubbed out of the gate new, I looked it over made sure I everything was in proper place and have taken the wheel off a few times and it now is all good. I too checked the the disk to see if it was not straight. Seems the more miles I put on it the better it gets. Are you getting a pulsing feel when applying the brake? If so ..not good. also grab the wheel and see if there is any play while its jack up off the ground and be forceful to simulate the weight of the bike and force it can create. Bad bearings if so. With no weight on it the wheel seems to roll true. Make sure you are snug on the axle bolt so you don't get side to side slop. __________________ Visit me on YouTube at "Project Next"! https://www.youtube.com/channel/UC6KTCi2GVbfRDv-2XCqHhsg?view_as=subscriber 2017 Bashan Storm Keihen PZ30 Pumper Carb,115 main jet,35 pilot jet, gutted factory exhaust, Sambo Digital Speedometer,LED blinkers, H4 headlight,D.I.D X-ring chain 428,17/42 sprockets,UNI cone filter.
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08-26-2018, 01:26 PM	#6
ChrisWNY Join Date: Jul 2018 Posts: 212	I feel a slight pulse with my front brake rotor as well (I feel the pulse in the brake handle itself, not anywhere else). I chalked it up to the rotor not being completely true but it doesn't seem to affect braking performance all that much so I've just rolled with it that way. Despite the pulsing, the brake pad wear seems pretty good and the surface of the rotor appears to be just fine. If applying the front brake is causing your suspension to go up and down, that sounds like it could be an entirely different issue, not just the true'ness of the rotor. Have you checked to make sure your brake pads are wearing evenly and is the surface of your rotor gouged or scratched up? __________________ 2018 RPS Hawk 250cc Mods so far: 1. Mikuni VM26 Carburetor w/#115 main jet 2. 17T/45T JT sprockets 3. JT 428 X-ring chain 4. Air box mod 5. Hawk Digital Cluster 6. Aftermarket IMS shift lever 7. Performance Aftermarket Exhaust 8. 295mm Nitrogen Gas Monoshock, 20W oil front forks
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08-26-2018, 09:26 PM	#9
Azhule Join Date: Dec 2015 Location: CO Posts: 1,525	You can still clean them up, just takes some elbow grease with that Brake Cleaner spray I usually go with Super Tech Brake Cleaner from Walmart... sure a few other "name" brands will clean a little better... but is it really worth the 4 - 7$ premium paying for a name?!? And if you are worried about "name brands"... just take a peek at the MSDS on the Super Tech Brake Cleaner, you will find out it is made by a well known chemical/oil company anyway __________________ "Think as you like... but this self proclaimed Professor is always right" - Buckshot "You never know what someone is hiding beneath their smile..." - NinjaTom - R.I.P.
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08-25-2018, 06:51 PM	#2
Lit Hawk Join Date: Oct 2017 Location: Houston,Tx Posts: 257	Looks like your bearings aren’t seated in evenly. I’d replace them with better ones than the stock. Front wheel bearings:6301-2RS
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08-25-2018, 09:46 PM	#3
Ac21 Join Date: Jun 2018 Posts: 54	How can you tell?
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08-25-2018, 11:15 PM	#5
Ac21 Join Date: Jun 2018 Posts: 54	It has about 700 miles. I wasn't very clear on the issue on the first post but pulsing feel when applying the brake is the issue it feels like it's getting worse, if I apply only front brake you can see the bike front suspension moving up and down.
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08-26-2018, 03:28 PM	#7
kirkallen143 Join Date: May 2015 Posts: 84	Did you clean the rotor and pads off with brake cleaner? They come shipped with an oil protectant of some sort. Same with the rear. Kirk
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08-26-2018, 07:32 PM	#8
Ac21 Join Date: Jun 2018 Posts: 54	The rotor surface looks good, I haven't checked the pads for even wear. I didn't clean the pads and rotor when I first got it so it may be that protection material on the rotor but now probably too late to clean off.
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