Metal Showing through at 250-300 miles?

[Sam Kennedy]

Hi, I got a specialized sirrus 2009 about 6 weeks ago. I must have only put on maybe 250-300 miles TOPS.

Already metal is showing through the back brake pads, they aren't worn down to the wear line either.

Should I ask my LBS to fix this as part of the free service, or just ask them to replace it on the spot?

Cheers

 

[PastyPower]

Some dodgy pads around, LBS may change them for you. I had the same problem, was a little concerned at first but just picked out the metal and carried on.

 

[HLaB]

I've had a similar problem in the past you should get it sorted before you damage your rims.

 

[very-near]

Are they sticking on (does it freewheel ? )

 

[Sam Kennedy]

yeah it does freewheel

 

[very-near]

Do you do a lot of hill work, are you particularly heavy etc ?

Seems unusual that they have worn so quickly.

 

[Sam Kennedy]

I don't really do too many hills, I weigh around 9.5 stone. I figured its not metal from under the pad, but metal from the rim coming off and sticking into the pad. Should that even happen?

 

[gavintc]

No, that is not normal. Something is definitely wrong there. You should check your rims, replace the pads and reset the brakes. Not a big job, but there is a real risk of damage if you have metal in the pads.

 

[jay clock]

I figured its not metal from under the pad, but metal from the rim coming off and sticking into the pad. Should that even happen?

I have to disagree with all the other comments. This is entirely normal and seems to happen on many of my bikes, partic with cheaper wheels

Clean the rims (non stick scouring pad and washing up liquid or Muc Off should do).

Take wheels out and clean brake pads thoroughly with rough scouring pad and washing up liquid or Muc Off. Use a tooth brush too. Get a very fine pointed knife and dig out the flecks of alloy. Use a bit of sandpaper to clean off the pads

Rinse down and you should have the problem solved. New wheels (partic if the braking surface is not machined) often do this, partic with the hard brake pads supplied with new brakes

If things are really bad, do all the cleaning, plus replace the pads with good quality softer ones

 

[jasonmccullum]

i had the same problem with all 4 of my brake pads and they damaged the wheels and i had to get the brakes and the wheels replaced.. i suggest you do the same, you dont want damaged wheels while riding downhill fast!!!

 

[fossyant]

What Jay clock said - clean the rims and pads - and it tends to happen on cheaper rims.

 

[Banjo]

On my Apollo CX10S I used to get this. To clean the brake block I used to cut a very thin slice off the surface with a sharp stanley knife type blade. I think grit from the road gets stuck in the brake block first which is what does the damage.Clean the blocks then check the surface regullarilly or you will grind away at the rim.

 

[Ian H]

If it's showing specks of metal then it's wearing the rim. If it's a large lump it's the metal carrier - in which case change it immediately.

I seem to recall that Shimano brake blocks were particularly hard on rims. Dunno if that's still the case nor if other original fittings are the same, but a change to Koolstop or similar might be beneficial.