2manybikes

The manufacturer makes an "approved" recommendation. The wrench reads it probably on the instructions that come with the brakes and other publications from the manufacturer. If you follow the manufacturers recommendations and something goes wrong at least you have a little bit of credibility if a bike shop questions you. If you don't they may not give you the help, advice, or warranty parts you need. You didn't follow the recommendations. Who can blame them? Denatured alcohol is easy to find and inexpensive. There may be other things that work, but why spend any time looking for them and experimenting? The disc manufacturers did all the research already. There is a good reason a manufacturer stays in business. They think about this before sending out printed material.

I'm not saying nothing else will work, but why bother looking? Minimize the chance of a mistake, minimize the time doing research. You might save $2.00 on a bottle of Denatured alcohol, but you may ruin your pads and rotors, or even the paint job.

Follow Raiyn's advice.

cyccommute 

I was a bit to smarmy in my reply also but I was feeling "teacherish" at the moment.

One thing you should know is that lemon "juice" isn't what is used in cleaners. Lemon juice is expressed from the pulp of the fruit and contains all of the stuff I mentioned. The lemon, and other citrus, cleaners use oils expressed from the peels of the fruit which is an entirely different animal. I would still not use these to clean a braking surface as they leave behind residues that would contaminate the brake surface and the pads just as plain soap can.

GV27

You got me there. I was just parroting the junior-high dropouts at Brembo.

cyccommute 

Sorry about that. My humor is an aquired taste.

You started in the right place, you just got the details wrong.

cyccommute 

Acetone really isn't that harsh as a solvent. It will take off fingernail polish but likely won't harm the paint on a modern bicycle. You shouldn't be spraying around any kind of solvent when working on a bike anyway. Put some on a clean cloth and scrubb away. If you use more than a teaspoon full (I'd use metric but everyone in the US would get all confused ), you have used too much!

Brake pads, even automotive pads, don't use asbestos much anymore. Pads fall into 3 broad categories: metal, organic and ceramic.

Ceramic are just that, ceramic. Very hard and very abrasive and very expensive.

Metal pads can be either sintered metal where a metal dust is heated and the metal particles adhere to one another. Or it can be metal particle imbeded in a resin matrix.

Organic pads can be made of fibers ...that's were asbestos used to be used... usually kevlar and metals, like copper or iron, in an organic resin. The resin of choice is usually phenol/formaldehyde also known as bakelite. PF resins are also use in plywood glues. It has a high ignition temperature and it is self extinquishing and it cheap to make. That makes it a great material to use for brakes because it won't catch on fire easily and it won't sustain burning. If you've ever been around I-70 coming out of Mt. Vernon Canyon here in Colorado, you can smell it constantly from trucks burning up their brakes but it seldom gets hot enough to catch the tires, and the rest of the truck, on fire.

wonko_the_chain

Ok, try this:

take a perfectly clean glass plate and spray your disc brake cleaner on it. wait for it to evaporate. inspect the glass plate by looking at it at different angles with respect to the lightsource. you WILL notice a thin film where the disc "cleaner" evaporated. this is known as residue.

car brakes generate huge amounts of heat compared to bicycle brakes. cars have much more mass to slow down and reach much higher speeds on a regular basis - this helps them "burn off" less volatile compounds compared to bicycle brakes.

You seem to have used automotive disc cleaner with success. To be anal about it, it DOES leave residue. Depending on the particulars, brake setup, tab alignment, rotor drilling and shape, pad compound, etc, such residue may cause problems. I didn't say it wouldn't work at all, I just stated that it leaves residue, don't make me break out the HPLC and give you particulars =]

thumbnut

The only thing that ever worked for me to clean the rotor and pads is to use brake cleaner or equivilent, then pop those babies in the oven at 300F for 1 hour. The oven thing burns off the residue and all the other crap still left. I can never work on the brakes or mess with the oil level in the forks or change springs without getting something bad on the brakes. I have an old toaster oven I use in the shop to shrink wrap fork springs, etc. Yea, its the one I first used to try this. The wife "gave it to me" after the smell of burnt something filled the air in the kitchen.

[bEn]

There should be a sticky for one of these threads. "How to keep your pads and rotors working well".

Raiyn

Must never have tried denatured alcohol. No fuss no muss no fire hazard

thumbnut

Tried it. So I put some on a glass plate and let it evaporate. There was residue left on the plate after it dried. Maybe it was cheap stuff? So I burn it off. Not sure what fire hazard there could be....

cyccommute 

I promised my wife I would be nice and let this thing die but you people keep bringing stuff up

Alcohol can be denatured in dozens of different ways. You can add methanol to it or isopropyl alcohol or, my favorite, gasoline. There are also other additives that can make it foul tasting. Each distiller will have its own recipe. So denatured alcohol may or may not leave a residue.

Brake cleaner is a mixture of various chlorinated solvents like those used in dry cleaning, toluene (a component of gasoline) and carbon dioxide. It may also have stabilizers added to keep side reactions to a minimum in the bottle. It may also leave a residue.

Commecially available acetone or paint thinner (my suggestions as well as denatured alcohol) also aren't pure. They don't have to be. Trust me, if you buy acetone that has been purified and is sold as pure, it still has some small amounts of other stuff in it. Maybe at the ppm or ppb level but they are still there. And you get to pay a premium for that purity ($50 to $60 per gallon vs $2 to $5 for the other stuff).

But, and here is the real issue, it doesn't matter! You are riding a mountain bike, not a "clean room" bike. There is more gunk on the trail that is going to get on your discs than you could ever get from a whole train car load of any of the above solvents! You will get a few micrograms of residue on your precious rotors. I have ways of detecting just how much you have on there but you don't! And trust me, you can't afford the detection method! So what if there is "residue" on your discs, it will scrape off or burn off when you put on your brakes the first time after cleaning.

If you go crazy with a grease gun or you like dipping your bike in WD-40 before each ride, by all means get some kind of cleaner (any one of the solvents discussed will do the job) and clean the rotors. Use it sparingly! If you use more than a tablespoon at a time you are using too much! And if you are worried about the extra weight that the residue adds to the rotors, trim your toenails before you go ride - you'll lose more weight that way. And if the thought of residue on your rotors drives you crazy because of your obsessive/compulsive behavior, go see your shrink

hooligan

Maaan, I have a french presentation, an optics test AND THIS TEST TOMORROW?! Jesus!

thumbnut

I was a lurker for a couple of years on another mtb discussion group. So I figured I'd get something started right away as a new member here...It worked. I have an appointment with my shrink next week.

swifferman

Just use alcohol. It's like $1 for a damn bottle that you won't run out of for a year if you're using it for just one bike.

cyccommute 

See. That's why my wife yells at me. I shoot off my mouth, offend people and be a general know-it-all pain in the lower extremities and then end up regretting it. I'll try to be better in the future.

southern91love

I know exactly how, hella easy, just throw some wd40 on and soak the pads with triflow. exactly what you need

Raiyn

That is exactly THE WRONG thing to do.

southern91love

i know, haha, i was just joking, besides, i like to kill kitens

Raiyn

Why the Hell would you joke about either subject? Giving bad advice like that can get someone hurt and I'm not even going into your kitten killing claims.

southern91love

XD hahahahahahha

Maelstrom 

Next time use something to show your sarcasm. Sometimes people read this stuff and might take it seriously, which could be dangerous

Check out the smilies at the side of the post maker...lots of things there to show some degree of sarc...like

southern91love

ooo, kinda like this... im going to kill a kitten with a hammer XD

Raiyn

You're wearing my patience down rather rapidly kid.

Dannihilator

Just how old are you?

southern91love

oooooooo i get it now thanks