[faraim]

Well after a few posts about pulsating brakes I finally broke down and bought a flex hone for rotors to recondition them,it WORKED.
Found a 60 grit on fleabay, removed them from the wheel,fixtured them into the cnc mill and went for it.
Pads replaced with Carbone Lorraine SBK (from NCRICK and Joyce at cojent dynamics Great people very helpfull)
Surface finish was not as good as original blanchard grinding,but the high speed vibration and low speed brake surging is gone.
First impressions are very good,took it out to bed them in and so far after near 200 mi still no problems and the pads seem to be coming arond niceley.
So after being skeptcal about stock pads having a transfer problem,I am now a beliver the hone was only 34.90 shipped and is much cheaper than the 5-600 for new rotors hope it lasts.
I am lucky enough to have a mill in my shop and was thinking how one could do this without and had the idea of removing the rotors,calipers and using some inexpensive aluminum spacers or washers from your local hardware store.
I will let everyone know how it works out one ay or another.

 

[dr1445]

for those of us without a mill or lathe, how about several sheets of 180 or 220 production paper and wet sanding on a flat plate. one side of the rotor would have to over hang the flat plate and be done a section at a time. the flex hone has the advantage of being able to follow the hills and valleys better, the question is how much better is needed.

 

[faraim]

I dont see that being a viable option because of the extreme time involved and keeping the two sides parallel.
However the flex hone is designed to be drill driven, so it can be done on the bike but you will have to flip the rotors. Just watch out for the buttons so they dont get scratched up and maybe rig up a standoff arm anchoring it to the front axel in order to keep a constant radius.
A drill press is another possible option even if you dont have one its a good reason to buy one,they are not that expensive.

 

[OregonAl]

Might not be a bad service to offer, have folks send in the rotors and you could hone them for a few bucks in labor. Beats replacement rotors as you say.

 

[Guest]

Might not be a bad service to offer, have folks send in the rotors and you could hone them for a few bucks in labor. Beats replacement rotors as you say.

Okay,i'm ready to send my back rotor,where do i send it to??

 

[faraim]

I was considering that while doing mine.
Let me put a few more miles on my fronts because I would not want to offer a service that would not last or solve a problem for anyone.As a side note the rotor must not be warped, as I suspect most are not from reading many, many threads on the subject.
Jet my rear was warped .040in and must be replaced the pic below of my rear rotor is an example of what can't be fixed.

 

[tahoest2]

I have a question about the pulsation you were feeling. Wondering if what I'm feeling is the same.

Around town riding, speeds under 40 I don't feel anything at all. Smooth. When I'm on some back roads, speeds over 50/60, etc.. When I hit the front brakes (especially a touch aggressive on the fronts), I feel a slight shudder/pulsation and then it will fade. But the front end will shake just a touch. Not enough to take me off my line but it's there.

Is what I've tried to describe sound like what you were dealing with? Or was your exp. much more dramatic?

 

[faraim]

trying to get pics to post but file is 2.1 mb per pic any suggestions?

 

[faraim]

I have a question about the pulsation you were feeling. Wondering if what I'm feeling is the same.

Around town riding, speeds under 40 I don't feel anything at all. Smooth. When I'm on some back roads, speeds over 50/60, etc.. When I hit the front brakes (especially a touch aggressive on the fronts), I feel a slight shudder/pulsation and then it will fade. But the front end will shake just a touch. Not enough to take me off my line but it's there.

Is what I've tried to describe sound like what you were dealing with? Or was your exp. much more dramatic?

In my case it was much more even with a very light touch of the lever, violent at higher speeds 70 + and completly unaceptable 100+
and at low speeds -20 I could actually feel wher the pads where grabbing at and was able to get a ref point by looking at the valve stem. Then when off the bike looked at the rotors but could not see anthing obvious
Are you able to check the rotors for warpage?
I suspect the same cause can manifest itself in different ways

 

[tahoest2]

I'm not personally able to measure my rotors for warpage. I did have my bike in recently for some other work. Two mechanics rode the bike and said it wasn't anything to be alarmed over or deal with. However, they didn't ride the bike past 40 is my guess as their shop is in San Francisco. Not much room to open it up.

I have found that when I apply slight rear brake it alleviates much of the bad feeling in the front.

 

[faraim]

Changes with application of rear brake:think: hmmmm
shop tells you not to worry about it, I think they did not want to bother with it.
did you mention that it changes with application of the rear brake?
My first thought would be head bearings worn/out of adjustment
is this problem on a monster,not that it makes a difference

 

[faraim]

pics on you tube
not repairable http://www.youtube.com/watch?v=DSFwfs5kST4
before and after http://www.youtube.com/watch?v=ufYHwC03i64
being resurfaced http://www.youtube.com/watch?v=CYyFstlm2o0

 

[Drbone641]

Of course you do realize that after your milling, that you now have a weaker rotor that may not pulse but will be thinner than stock. The warp will return. I had same and after being denied repeatedly by Duc NA, they replaced rotors and pads. Fixed. Warped rotors are annoying in a car. Dangerous on a Front brake on a bike.

 

[faraim]

Yes you would be correct if I "milled" the rotors however they have only been honed enough to remove the pad transfer.the chips you can see in the vid are from a previous job and are aluminum .As I stated earlier the proof will be in the long term performance.

 

[faraim]

Update,
Another 300 mi and no problems to report brakes are doing very well

 

[OregonAl]

that is good news. how much of a pain is it to break the bolts loose that hold the disc on?

 

[Gearbox]

trying to get pics to post but file is 2.1 mb per pic any suggestions?

I know the following suggestion is a bit low-tech and layman'ish but I email photos to myself and use the automatic windows programme that asks if you ant to reduce the size.
I then open the incoming mail and save the attachments to a folder marked - Re-Sized and then use those for postings/discussions.
I know others ahve more professional methods but thsi works for me

 

[Gearbox]

In my case it was much more even with a very light touch of the lever, violent at higher speeds 70 + and completly unaceptable 100+
and at low speeds -20 I could actually feel wher the pads where grabbing at and was able to get a ref point by looking at the valve stem. Then when off the bike looked at the rotors but could not see anthing obvious
Are you able to check the rotors for warpage?
I suspect the same cause can manifest itself in different ways

Classic pad material build-up - it can also be addressed by access to a glass bead (not shot) blaster which will remove the debris (you can mask everything except the rotors).

The rotors are very rarely warped and in fact difficult to diagnose as such without dismantlling them fully)
The fact that the problem goes away when both discs and pads are replaced is innevitable and hardly surprising as the offending items have both been replaced (thats fine if somebody else is paying but with discs & pads costing UKPS 500 + not something wanting to be done by a paying customer , rather like replacing your car because the ash-trays are full......fien if you can afford it !)

If the pulsing disappears at low speeds then this is not the same problem and as others have suggested may be wheel bearings/head bearings or even mis-balanced wheel.

 

[faraim]

that is good news. how much of a pain is it to break the bolts loose that hold the disc on?

I did mangle one worn snap-on torx drive but gentle heat should realese the locktite

 

[faraim]

I know the following suggestion is a bit low-tech and layman'ish but I email photos to myself and use the automatic windows programme that asks if you ant to reduce the size.
I then open the incoming mail and save the attachments to a folder marked - Re-Sized and then use those for postings/discussions.
I know others ahve more professional methods but thsi works for me

if it works why not? sound easy enough will try that next time,thanks