godspiral

I have a trek 470 from mid 90s with RSX level components, and shimano brake pads. I don't think the bike has been used very much, but the rims are quite heavily worn, and braking makes a loud scraping/grinding noise whenever they are used. I've seen other brake pads like this, so I'm assuming that this is intentional design. They do stop very well with little pulling effort.

Is there a technique to limit the amount of rim wear with these types of brakes?
Cool stop reds and older style road pads are much softer I think. If I don't change pads, will the rims need replacing soon? replacing can be avoided by switching to soft pads?

operator

Kool stop pads, the reds ones that is wears the rim faster than the black ones. If your current pads are making a scratching noise (they shouldn't), get some new ones. Your current pads will wear the rim enough until it fails while riding.

The technique to limit rim wear is to get disc brakes. Rim wear with rim brakes are a fact of life. Or ride brakeless fixed gear.

Dersu Burrows

Try removing the pads and inspecting them for damage. I have found that little bits of aluminum from the street get stuck in there which can cause serious damage. Use a sharp-pokey (awl or similar) to dig the bits out from time to time.

slvoid

Not only aluminium, its the glass and all the other crap too. They get stuck in your pads and may even wear a groove into your rim, weakening it. KABLAMO!

Al1943

I just automatically replace all Shimano brake pads with KoolStop pads. I use the black type.

Al

godspiral

I replaced them with old 70s road pads for now, and its much better. Still stops great.

brand new Nashbar brake shoes had the same problem as these shimano pads. Its like the pads are metal with a very thin toplayer of rubber. It all looks to be on purpose to me.

donnamb 

Kool Stop makes reds and salmons. Do you really mean just the red or both?

operator

Both, since they're the same thing.

Namenda

Nashbar brake pads are molded crapola. They grind on the rim, making a ruckus, whilst doing next to nothing to actually slow the bike, let alone stop it. A terrible product. I realize Nashbar doesn't make them...but I would hope they could find a new supplier, preferably one with a clue.

well biked

www.koolstop.com/brakes/Compound.html

The Kool Stop salmon compound is the same as the old Scott-Mathauser compound, and is the best compound out there in my opinion-

LóFarkas

I'll add another vote to "those are most likely crap pads". Remove, inspect, clean (awl, file, sandpaper), clean the rim, reinstall. If things don't improve, or you don't want to screw around trying to fix a junk part in the first place, buy Koolstop.

Michel Gagnon

I'm not sure exactly where it was explained very clearly, but Kool Stop has a very sketchy chart.

There is a great difference between Red and Salmon pads, they are NOT the same!

The Black pads work great in dry and rainy conditions. I have no experience with Coloured pads (red, blue, silver or yellow, they are the same), but have heard that they are less interesting than either Black or Salmon pads under most conditions.

As for the Salmon, they work very well in rain, snow, sleet, etc. I have no real experience in mud, but I could say that dirty snow is not exactly rim friendly. Salmon pads could work under all conditions, but I find them a bit sub-optimal on dry roads. This is where the "Dual compound" is useful, as it seems to bring a fairly constant behaviour under all conditions.

As for "pads eating the rim", I haven't seen that with Kool Stop Salmon or Dual pads, which are the only ones I have used for many years in a row. And I clean rims and pads very rarely if ever. However, if some piece of crud comes imbedded in the pad or if you have a defective well worn out rim, or a rim sporting heavy scratches from sidewalk kisses, then your pads will pick up metal shards which will then work their way though the rim.

BTW, in five years, I think I stopped only once because of screeching stratchy brakes. Turned out a screw was imbedded in a brake pad.

operator

Source of information please?

DMF 

Look at the KoolStop compund chart cited above.

operator

Seems like I was wrong - in that case I was referring to the salmons.

godspiral

Taking the brakes off, I noticed that the surface seemed to be metallic and shiny. Probably from rim shavings embedded on top. Can I take a rotary tool to file off all the metal, and then use the pads on another rim and perhaps that rim will not disintegrate?

DMF 

Not sure I'd use a rotary tool. That will leave an irregular surface. Try a file along the length of the pad, and pick out any big pieces with a sharp tool. Works for me.