Front brake vibration?

[WJBertrand]

Never had a bike with sculpted pedal type rotors before, so I'm not 100% sure this isn't normal, but my bike seems to produce a vibration when braking at highway speed from the front brake. It's most noticeable on light application, then kind of goes away or is subdued as I brake harder. Once at near stopping speed, I can feel a mild pulsation. I suspect a warped rotor or rotors up front? I'm still under warranty so I'm thinking to have the dealer look at it.


-Jeff

 

[Juan]

How many miles on the break pads? If they're new they have to settle in.

 

[WJBertrand]

Thanks for the reply, almost 17K miles. The pads still have plenty of material left in them as well.


-Jeff

 

[AVGeek]

What tires do you have on the front? They can play a part as well.

 

[WJBertrand]

What tires do you have on the front? They can play a part as well.

Good point, I still have the OEM Battle Wing on there. Other than being a bit shallow on tread it doesn't look lumpy or oddly worn in any way. There is an A40 Battle Axe on the rear.

 

[tomatocity]

Good point, I still have the OEM Battle Wing on there. Other than being a bit shallow on tread it doesn't look lumpy or oddly worn in any way. There is an A40 Battle Axe on the rear.

You have 17K miles on the original BW tire? Retire the Wing and mount the Battlax A40. You will like the new tire and remove one possibility of the vibration. The A40 made me a more confident rider and I have had my share of Battle Wings (a very good tire).

 

[Juan]

He said 17k miles on the break pads, not tyres. But even that is a little too much especially for the rear pads.

 

[Gigitt]

Try cleaning the rotor bobbins with brake cleaner.
The rotors floats from the mounting hat with bobbins (donut rivets), when brake dust and dirt get in the gaps and stop the rotor abliity to float you can get braking vibrations - it is not a warped disc.

get a short bolt and nut that fits in the hole of the bobbins, and 2 washers. fit a washer on the bolt put it throught the bobbin then washer and then tighten the nut on by hand. take a wratcheting wrench/socket and just lock the bolt onto the bobbin and wrench the nut clockwise - you dont have to tight it wrenching clockwise will grip the bobbin, the bobbin should spin with little effort. If not spray some brake cleaner in the gap wait 30 sec and spin the bobbin again. Do this for all bobbins.

DO NOT spray WD40 or other lubes to free the bobbins...

 

[WJBertrand]

He said 17k miles on the break pads, not tyres. But even that is a little too much especially for the rear pads.

Both the front tire and the front pads are original and have almost 17K on them.


-Jeff

 

[Rodge]

Both the front tire and the front pads are original and have almost 17K on them

-Jeff

You're a smooth rider my friend...
Warp rotors are often mistaken for pad material deposit on disc, with 17k on pads and tire that is not your case, unless you went into a crazy banzai ride lately...
Double check your free floating calipers like Gigitt said...
New front tire could also play here...
However, I'm going to go outside the box here, stay with me, you change your rear spring, what is your damping setting on your ES, go softer, this will lessen the compression and rebound in the front.
I went from Soft +2 to Soft -3 and don't feel the wallow (slow pulsating vibration?) in the front at initial brake application, this is an easy thing to check with the flick of the switch.
Cheers

 

[WJBertrand]

You're a smooth rider my friend...
Warp rotors are often mistaken for pad material deposit on disc, with 17k on pads and tire that is not your case, unless you went into a crazy banzai ride lately...
Double check your free floating calipers like Gigitt said...
New front tire could also play here...
However, I'm going to go outside the box here, stay with me, you change your rear spring, what is your damping setting on your ES, go softer, this will lessen the compression and rebound in the front.
I went from Soft +2 to Soft -3 and don't feel the wallow (slow pulsating vibration?) in the front at initial brake application, this is an easy thing to check with the flick of the switch.
Cheers

Thanks for the reply, I do try to be smooth as possible. I've done a number of track days with the MCN crew and smoothness is instructed and highly stressed. My 40+ year experience has convinced me that tire and brake wear have more to do with riding style than pavement type, temperatures, loading, speed or even tire brand, than anything else.

With respect to my damping settings I have the bike set at rider + luggage and damping sent to standard +3. I'll try playing with the settings to see if that makes any difference as well checking/cleaning the floater buttons. While I'm at it I think I'll take some a scotch brite pad and some brake cleaner to the rotors themselves. I've noticed the problem seems worse the more braking I do, so maybe it's heat related?

 

[Rodge]

Thanks for the reply, I do try to be smooth as possible. I've done a number of track days with the MCN crew and smoothness is instructed and highly stressed. My 40+ year experience has convinced me that tire and brake wear have more to do with riding style than pavement type, temperatures, loading, speed or even tire brand, than anything else.

With respect to my damping settings I have the bike set at rider + luggage and damping sent to standard +3. I'll try playing with the settings to see if that makes any difference as well checking/cleaning the floater buttons. While I'm at it I think I'll take some a scotch brite pad and some brake cleaner to the rotors themselves. I've noticed the problem seems worse the more braking I do, so maybe it's heat related?

Oh the lesson I had from an instructor on a stock SV 650 on a Donnington track day... smooth is fast... ;-)
Sounds like you have material deposit, or pads contamination (oil, etc), check your calipers (sticky, non floating) and pads, scrubbing the rotors might help.
You may want to do a pad bedding session after that, find an empty stretch of road, from 60 mph brake hard up to impeding lock up, do that 5-6 times with a brief cooling period in between.
Let us know what you find.
Cheers

 

[Cycledude]

I wonder if he ever got it fixed

 

[WJBertrand]

Sorry to leave this hanging. No fix yet, I did scrub the rotors with a scotch-brite pad and some brake cleaner but did not see any improvement. I checked the floating mount "bobbins" and they don't seem to move at all by hand. I haven't yet applied any tools to them. I've decided to wait to take it to the dealer until I've fitted new tires as I'm sure they'll just turn me away with such a worn front if I went in now.

 

[Dogdaze]

So I'll post my findings, as I had the exact same issue, under normal/heavy braking perfect! Any light braking and the this sends a judder through the front end, did as someone suggested and spun all the bobbins (used a drill on slow), cleaned the callipers, even used a toothbrush, still no change, finally decided to replace the oem pads after 18.5k miles, were not worn, but might as well, and .................... no change, bollocks! So yesterday, took out the slider pins, wire wooled them and applied copper grease. Took the bike out today because I suffer from OCD so it eats away at me until fixed and......................... bingo! By George I do believe I have smooth brakes now. Man that was sooooo annoying (probably due to being a bit OCD)

 

[WJBertrand]

Thanks, I'll give that a go. So I guess you mean the pad pins? As the Tenere has dual action calipers there are no caliper slide pins.

 

[Dogdaze]

Thanks, I'll give that a go. So I guess you mean the pad pins? As the Tenere has dual action calipers there are no caliper slide pins.

You're right, the calipers don't actually move, so the pad retaining pins, take out the two cotter pins, slide the pin out, watch the plate spring fly out into a dark corner of the garage, clean up the pad pin, apply copper grease, reverse the procedure and with any luck you should have the same result.

 

[TimLaw]

Something like that happened with me at around 4k. Almost like a clicking noise. I took it in and they checked everything and figured out the tree was slightly off. They readjusted it, and it was fine. It cost me $45