1984 FJ11 Brake Rotors

[fj1289]

I plan to buy one of the flex hone brushes Pat posted earlier.

Pat - you should post that in the new tools section

[FJ1100mjk]

Get the right tool for the right job.

Exactly

So Marty, you, personally, would use this on your brake rotors?

If that's all I had, then sure, I'd give it a go. Sure beats the other, more labor intensive, method that I used in the past before coming across the Flex-Hone rotor tool seven or so years ago.

My past method I will not divulge, due to fear of it not being compliant with the FJowners.com approved methods and tooling. 

[ribbert]

Couldn't the same reasoning also apply to those that showcase their bling, such as an automatic chain oiler, stainless steel braided brake lines, or a GPS unit? It's not a stretch to envison a mechanical novice installing items like these and having disastrous results. Either with their install or use.

Where is the line drawn for those that post for the benefit of others, but shouldn't because of it being deemed a dangerous practice by others?

Where indeed?

Only a few weeks back we had someone post up about tightening clutch bolts until the spring was compressed, the bolt bottomed out and then cracked the clutch basket - with a tension wrench! Do we suggest not using a tension wrench? No. Imagine if that had been rotor bolts or caliper bolts or banjo bolts.

You can't guard against everything. The examples you mentioned Marty, the installation of a chain oiler or GPS, like most other jobs on the bike, isn't going to kill you if done badly. I have however seen poorly routed and over clamped brake lines fail.

There are a number of things I try to consider with every post, one of them is, what's the most trouble the most mechanically challenged person to read this can get into following my advice. I do not post a lot of the stuff I do for this very reason. Suggesting an angle grinder and brake rotor in the same sentence is IMO ill advised, especially when it's not necessary. As sure as the sun coming up tomorrow there will be someone out there who will read that and take an angle grinder and cutting/grinding wheel to their rotors, and that could kill you.

I remember two occasions where owners have followed the instruction "Fill the engine with oil" literally. One of them, when buying oil, commented that while his owners book said 5 litres, he'd already put 3 times that much in and it still wasn't full!

I have seen an owner put oil so thick in his engine it sheared the drive off the oil pump when he started it. Someone had suggested it might run better on thicker oil, they just didn't say how thick. The owner thought if thick is good, thicker must be better.

I've seen a piece of water pipe used instead of a king pin on the advice of a mate and so on....

More recently, and on a lighter note, someone I know pulled over on a country road and called roadside assistance when a warning light came up on the dash of her new Audi. The bemused mechanic explained the symbol was a stylised cup of coffee, the car was telling her she had been driving for 2 hours and needed a break.

You can't draw a line nor protect everyone from themselves but common sense suggests that failed brakes are dangerous and just think when posting about the possibilities of what some mechanically inept DIYer could with that snippet of information and how he might interpret it based on the tools at hand and complete lack of knowledge. This only matters if it's potentially dangerous, if not, let 'em rip.

IMO

Noel

[fj1289]

Holy cow!  She deserves a party for not simply ignoring the light!

[Pat Conlon]

Hey, at least she's paying attention to her dash board.....

Driving a new $80,000 Audi and a red dash light comes on...is that a coffee cup, or an oil symbol? Yes, I know, read the owners manual..still...

It's ignoring CEL's that frosts me...

[Sparky84]

As sure as the sun coming up tomorrow there will be someone out there who will read that and take an angle grinder and cutting/grinding wheel to their rotors, and that could kill you.

No angle grinder, cutting/grinder wheel will ever touch my disc's that I would Using, only if I was making a sculpture 
Slight rub with wet and dry would be the closest I'd go to a grinding disc, but I do have one of those
Flex Hone Tools

I've seen a piece of water pipe used instead of a king pin on the advice of a mate and so on....

I've seen a nail used as a fuse wire, they couldn't fit it in the fuse so they removed the whole fuse and wrapped the wires to it! 

it based on the tools at hand and complete lack of knowledge.

And common sense

Cheers Alan

[ZOA NOM]

Brakes just slow you down. Too many snowflakes these days...

[Firehawk068]

I use the "Flex-Hone" tools that Pat had posted.
I have both a medium grit one, and a coarse one.
I use them as Pat had described, in both directions. I usually use both grits also. Start with the coarse, then finish with the medium.
An electric drill is all you need, and they actually work best on the slowest speed settings.

[bigbore2]

Gentlemen, gentlemen. I knew if I posted that I would get opinions.

One of you, with an opinion, but no experience in doing this, hows about listing WHY this is a bad idea?
You say its a bad idea, but why?  I have a successful application of this method, all 3 rotors on my 84 were done this way, carefully watched while breaking in, and over 15,000 mi of success on my stock setup.

I have done many sets of car brakes and understand the idea here on how brakes work.
I originally was looking for a shop who turned rotors, but could not find any who did motorcycle rotors.

A lifetime mechanic introduced me to this method many years ago as we were rebuilding a car together.
I decided to try it on my bike rotors, successfully applied to 1 dirt bike and my 84.

So I guess being successful doing this is not good enough criteria for some of you. Fine.  I owe you a beer.
but please tell me why this is a bad idea. And you better be able to back up that rebuttal with something more than just an opinion....

and just to say, I love this site and the many members here.  You guys crack me up sometimes.

[ribbert]

One of you, with an opinion, but no experience ....

I don't need to place my bare hand into a pot of boiling water to know it's a bad idea. I know about power tools and metal. Experience? Yes, I have that - and qualifications.

I originally was looking for a shop who turned rotors, but could not find any who did motorcycle rotors.

The reason you couldn't find a shop to turn bike rotors is because you don't. No brake shop would do it. They are a single use consumeable, wear them down, throw them out. They are not like cast iron car rotors.

..... And you better be able to back up that rebuttal with something more than just an opinion....

Bigbore, if you can uniformly remove metal over the entire surface of a rotor with a hand held tool you are indeed a legend. 

Anyway, you have rolled two subjects into one, the merits of the procedure and the wisdom of putting it on the forum.

What you do to you own brakes is your business, my concern is limited to posting a dodgy and potentially dangerous procedure on line that someone else without your skill might try. If it was anything other than brakes I wouldn't care.

Why are you doing it the first place? Perhaps you could explain that for the "inexperienced"

As for "backing up the rebuttal with something more than just an opinion" It's not required, the folly of the procedure speaks for itself, and that's a fact.

Noel

[aviationfred]

Get the right tool for the right job.

Exactly

So Marty, you, personally, would use this on your brake rotors?

Too answer this question.... Using the soft abrasive fiber discs that Marty posted....I would..... Using a pneumatic 20000 rpm angle grinder. Again, the right tool for the job, Plus the skill set to use it properly


I am going to weigh in on this, as I believe there are two different tools being talked about. I believe what most are envisioning with the mention of a die grinder is.

An electric die grinder. 7000-10000 rpm with a huge amount of torque. Pictured in photo #1. I will agree with Noel and Pat. To use this tool to grind a few microns off of your rotors is highly ill advised.

On the other hand, I believe what Marty is referring to is a pneumatic die/angle grinder. Pictured in photo #2. These normally spin in the neighborhood of 12000 to 25000 rpm, but with very little torque. Using the blue scotch brite type pads that are available for these grinders and a very light touch, removing the brake pad glaze from a set of rotors is very easily done.

IMO, the tool Pat posted is still the best option.

Fred

[FJmonkey]

FYI, reply 22 is the mention of an Angle Grinder by Bigbore2. Marty was only questioning where we draw the line with offering advise/tools/techniques. With the definition of what an Angle Grinder is, not being the same in everyone's head, the assumptions began. In spite of the confusion, some good options have been presented and are readily available around the world. Grind away...

[ribbert]

I am going to weigh in on this, as I believe there are two different tools being talked about. I believe what most are envisioning with the mention of a die grinder is.....

Fred

Fred, no one mentioned a die grinder, he said angle grinder. Many wouldn't know what a die grinder was anyway.

Noel

[ribbert]

.... With the definition of what an Angle Grinder is, not being the same in everyone's head....

Mark, shirley you can't be serious. Drill, circular saw, angle grinder. The three most identifiable and owned handyman tools on the planet. This whole notion of hand grinding rotors gets scarier by the minute.

Noel

[ribbert]

To take this back a step, I have always been curious as to why folks do this anyway. What is the advantage and do you put your pads on a belt sander so they are matched to your now smooth discs or hit the road with smooth rotors and grooved pads?

Seriously, I've never understood why people do this.

Perhaps someone can explain.

Noel