Disc brakes

[TakeTheHighRoad]

How long should they last? And how do I know whether they're worn?

I got my first bike with disc brake about 1000 miles ago, and the braking has been quite poor on them recently. I can't tell whether they've faded or what, and looking for advice on how to fix (is it a case of getting new pads?)

 

[All uphill]

How long should they last? And how do I know whether they're worn?

I got my first bike with disc brake about 1000 miles ago, and the braking has been quite poor on them recently. I can't tell whether they've faded or what, and looking for advice on how to fix (is it a case of getting new pads?)

Which disc brakes? Cable or hydraulic?

With a used bike I'd be keen to clean the discs, and maybe replace the pads, and bed the new ones in properly before judging their effectiveness.

 

[N0bodyOfTheGoat]

I don't think I've specifically replaced a hydraulic disc rotor from wear since my first bike with them back in 2008, my old neon orange Saracan Pylon 8 commuter.

Shimano pads typically last me approx 2-3 years with outdoor hilly rides March-November, on my old flatter commute bikes they'd last 3+ years. There's probably a pad depth minimumm, beyond which they ought to be replaced, but I can't recall what it is. My Cube road bike front pads (that will wear quicker because they do more of the braking for me) are maybe ~0.5mm and need replacing, I could tell bike wasn't slowing anywhere near as good as my GT ebike.

 

[brommieinkorea]

Never had to replace a rotor. Sounds like the things are just out of adjustment, pads wear and you have to manually move the worn pads towards the disc (unlike on a car where the pads don't retract).Most discs have a knob or screw on the sides of the caliper for this, real simple. I'd also check to see that there's no oil or oily residue on the discs/pads. It's lots easier to get lube on a rim than a disc while lubing the chain, but it happens.

 

[Drago]

Piece of string.

Off road in muddy conditions a vigorous rider can knock out pads in a day.

On road with a rider with good observation skills who plans ahead and who doesnt comfort brake like many riders do the pads might outlive the rider.

First port of call is eyeball the pads and see out much meat is left on them.

 

[Ming the Merciless]

Rotor when it drops to 1.5mm thick. Pad material 0.5mm or if getting close to backing plate. With hydraulic when you start seeing increased lever travel before bite, it is time to inspect as well.

The rotor should be fine at 1,000 miles. I typically replace rotors at 20,000 miles and pads roughly 2,500 - 3,000 miles. Though both are subject to periodic inspection, rather than going by distance.

 

[richardfm]

Check for wear as Ming The Merciless advises and clean the rotors, with IPA or Brake Cleaner. Clean the pads with Scotch Brite or other abrasive and then bed the pads in.

If they are cable operated they may need adjusting, if they are hydraulic they may need bleeding.

 

[TakeTheHighRoad]

Thanks for the info, sounds like one to have a look and see what's going on rather than replacing straight off the bat

 

[Webbo2]

Check for wear as Ming The Merciless advises and clean the rotors, with IPA or Brake Cleaner. Clean the pads with Scotch Brite or other abrasive and then bed the pads in.

If they are cable operated they may need adjusting, if they are hydraulic they may need bleeding.

I can understand maybe cleaning the rotors with vodka but Imperial Pale Ale seems a bit over the top.🍺

 

[ebikeerwidnes]

I find that my LBS seems to want to replace the pads about every 2 years

however, if they fade then he says they are dirty so have been corrupted and he replaces the pads

I take the whole thing in for a good going over - and the ebike system to be run through the Bosch system to check it out - every year and he always says he had adjusted them

he has replaced the discs a coupel fo times in the last 6 years - but at least once that was them having "something" on them and it just got to the point where it was easier to just replace discs and pads and get it sorted


One thing I have read about but had never been a problem is the
"never turn the bike upside down if you have hydraulic discs" is rubbish

I turn it upside down whenever I give it a full clean or oil the chain etc
and I have never got air locks in the pipes

I asked the LBS and they agreed - if the fluid is done properly then air locks are not upside down

 

[richardfm]

I can understand maybe cleaning the rotors with vodka but Imperial Pale Ale seems a bit over the top.🍺

For avoidance of doubt IPA is Isopropyl alcohol in this instance, not India Pale Ale or Double IPA, sometimes known as Imperial IPA. I'm not aware of a beer style known as Imperial Pale Ale