My brake blocks appear to be eating my rims

[Ihatehills]

The brakes on my two week old specialized sirrus were getting increasingly noisy, when I went to clean the the rims and blocks I found fairly large bits of aluminium embedded in the block ( see attached ) I don't know why this has happened and am concerned that I've knackered my wheels. All advice appreciated

 

[adamhearn]

It's pretty normal to pick up bits of the wheel in the blocks (wheels are meant to wear). Consider all the crap (road debris) a rim will pick up [especially when wet/muddy] and them what happens when you grind it into the rim whilst forcing the blocks to slow you down Clean them and pick out the embedded bits and you've done all you can to ensure longest rim life possible.

You can also swap out 'hard' pads for ones that are softer/kinder to aluminium rims.

 

[Shut Up Legs]

Just remember that the softer pads will of course wear out sooner.

Another thing you can do to prolong rim life is to clean the rims regularly. I generally use a cloth and some general-purpose spray cleaner (Ajax: do you have that brand in the UK?). If you really want to take extra care of the rims, you can use a rim-cleaning block (e.g. one of these: http://www.chainreactioncycles.com/au/en/swissstop-swissclean-rim-cleaner/rp-prod42618), but I find them tiresome to use, and hard on the wrists.

 

[vickster]

I just clean my rims with baby wipes

 

[SamR]

I don't think it would be pieces of your rim lodged in the brake pads, more likely bits of debris that you pick up on your travels.
It's not uncommon for people to clean out their brake blocks quite regularly to remove debris lodged in them.

 

[Gravity Aided]

I clean my rims with an orange degreaser, due to picking up a lot of oil on roads. I normally just clean the brake blocks with degreasing dish soap or auto shampoo(preferred), but I commute a lot on my bicycles, and cover a lot of varying road surfaces. I may be going the baby wipes or cleaner wipes route soon, for convenience, on the wheels

 

[migrantwing]

Lighter fluid works well. Surgical Spirit or White Spirit, too.

 

[summerdays]

When I first returned to cycling, I didn't realise the importance of cleaning the brake blocks and rim, and learnt the hard way when I had to have new wheels in 18 months as I'd worn the rims down so much. That was one of the reasons that the next bike had disk brakes.

 

[BigAl68]

I clean my rims every week and the pads as you pick up so much crap on them otherwise. I use a scotchpad on the pads or sometimes sandpaper. Its far cheaper to replace pads than your wheels.

 

[screenman]

Err! Brake cleaner works quite well for some reason.

 

[Yellow Saddle]

The OP's observation is correct. Those shiny bits are pieces of rim and if he posts a picture of the rim, you'll see rough tracks around the brake track.
This happens when crappy rubber is used on the brake pads. This won't happen with Koolstop pads and others with Iron Oxide in the rubber. Koolstop had a patent for pick-up free rubber but that has not expired I think, and the likes of Shimano now also have that technology in their upper end rubber.

Brake pads have extremely high heat at the surface and with the wrong rubber, some hard crystals form in the rubber and abrades the rim.

The cure is Koolstop Salmon for sure, but I'm unsure which other pads use the same rubber. I suspect that Shimano's new upper-end brakes come with that type of rubber.

This cannot be cured by keeping the rims or pads clean and baby wipes, aircraft afterburner fuel and other bogus remedies should best be reserved for their intended purpose.

 

[summerdays]

The OP's observation is correct. Those shiny bits are pieces of rim and if he posts a picture of the rim, you'll see rough tracks around the brake track.
This happens when crappy rubber is used on the brake pads. This won't happen with Koolstop pads and others with Iron Oxide in the rubber. Koolstop had a patent for pick-up free rubber but that has not expired I think, and the likes of Shimano now also have that technology in their upper end rubber.

Brake pads have extremely high heat at the surface and with the wrong rubber, some hard crystals form in the rubber and abrades the rim.

The cure is Koolstop Salmon for sure, but I'm unsure which other pads use the same rubber. I suspect that Shimano's new upper-end brakes come with that type of rubber.

This cannot be cured by keeping the rims or pads clean and baby wipes, aircraft afterburner fuel and other bogus remedies should best be reserved for their intended purpose.

You still need to clean off the crud that builds up on the rims and even with Koolstop pads you get that. Baby wipes have worked for me to clean off that rubbish.

 

[Yellow Saddle]

You still need to clean off the crud that builds up on the rims and even with Koolstop pads you get that. Baby wipes have worked for me to clean off that rubbish.

The OP was looking for a cure for the aluminium pick-up, not suggestions for cleaning his bike. Like I said, crud or no crud, pick-up has nothing to do with crud.

 

[Yellow Saddle]

Here is an experiment I often did after it became known in the 1990s that Koolstop had a cure for the problem.

A Shimano pad on the left (black one on top), a Koolstop pad on the right and a long ride in the wet. Shimano does pick up aluminium, Koolstop not. The bottom picture shows rim damage done by the black pad.

These photos are not mine but I have repeated the experiment a few times for customers over the years. On my own bike I fitted Koolstop from the start and the rim never became abraded like this, even though it gets pretty dirty when I ride in the wet.

 

[uclown2002]

@Yellow Saddle so what do you recommend for cleaning rims?