BB7 disc brake pad life. The final definite answer, which is completely and utterly the last word. FOR EVAAAA!

[scotsbikester]

Pre cycling holiday checks.

Front wheel out. Measure thickness of pads. Avid say friction material+backing should be => 3mm.

Failing eyesight means Vernier guage not quite accurate enough. Out with the micrometer I recently inherited. Work out how to use it. Then measure, in several places. Which was remarkably consistent.

That's an imperial micrometer, but if I've a) read it right and b) converted to metric correctly, there is 3.683mm of pad+backing on that used one.

So how much is there on a new one? I hear you ask:

That's 3.987mm. No, no, no, that's not "nearly 4mm", this is a very carefully controlled precision study.

Avid say 3mm is wear limit. So 3.987-3.000 is 0.987 wearable material.
My worn ones have used 0.254 mm (3.987-3.683), 25.7345% of the wearable material.

I log every ride using either my phone or sports watch, and track component usage using Quantify my bike. Those pads have done 2020 miles.

So Avid BB7 pads (these are the Avid metal sintered ones) last for 7,849.38506674 miles.

Approximately.

 

[fossyant]

Well, to chuck a spanner in the works. Ride the same pads on a wet day in the Peaks (off road) and you won't get 30 miles out of them.

 

[scotsbikester]

Update. After much careful mensuration it turns out the rears are two thirds worn after about 3000 miles. Which is odd. I'm wondering if at some point I replaced the fronts and forgot I had done. Mmm.

 

[roubaixtuesday]

I see disc brakes continue to be maintenance free.

[ducks for cover]

 

[scotsbikester]

I see disc brakes continue to be maintenance free.

[ducks for cover]

Indeed. One of the advantages of rim brakes is never having to replace the pads. Ever.

 

[fossyant]

Indeed. One of the advantages of rim brakes is never having to replace the pads. Ever.

I assume you don't ride in the wet then. If I have a wet 'period' when commuting, I'll eat the pads in about 2 months in winter. Let's say I had a set of new pads on when I did the KAW last September. 450km later they were well worn. New fitted.

 

[scotsbikester]

I see disc brakes continue to be maintenance free.

[ducks for cover]

As it happens somewhere* I have not one but two Carrera Subways with hub brakes. Which were supposed to be genuinely maintenance free. No replaceable shoes or pads or whatever. I didn't ride them much, I was mainly attracted to the idea of a very low maintenance bike, as they've got hub gears too. I didn't find the brakes as bad as a lot of people say, to be honest. One day, when I've got the room, I will resurrect those as dirt cheap commuter/shopping/don't-care-if-nicked bikes.

*"Somewhere", meaning the loft. I have six (!) bikes in my loft. With the wheels off, as that was the only way to get them through the 20" hatch. As you can imagine, that was a fun day, wrangling those through that hole.

 

[scotsbikester]

I assume you don't ride in the wet then.

Not if I can help it.

 

[ktmbiker58]

As it happens somewhere* I have not one but two Carrera Subways with hub brakes. Which were supposed to be genuinely maintenance free. No replaceable shoes or pads or whatever. I didn't ride them much, I was mainly attracted to the idea of a very low maintenance bike, as they've got hub gears too. I didn't find the brakes as bad as a lot of people say, to be honest. One day, when I've got the room, I will resurrect those as dirt cheap commuter/shopping/don't-care-if-nicked bikes.

*"Somewhere", meaning the loft. I have six (!) bikes in my loft. With the wheels off, as that was the only way to get them through the 20" hatch. As you can imagine, that was a fun day, wrangling those through that hole.

Ah the garage in the loft - word of advice, don't install a permanent loft ladder after you've secreted part of your fleet in the attic, they will be stuck up there forever unless you remove the loft ladder - don't ask me how I know

 

[ebikeerwidnes]

Ah the garage in the loft - word of advice, don't install a permanent loft ladder after you've secreted part of your fleet in the attic, they will be stuck up there forever unless you remove the loft ladder - don't ask me how I know

Loft hatches shrink over time

I know this because my wife's old house had the original ceilings and loft entrance
and there was a large plastic box up there that her son clearly remembered taking up there but neither of us could find any way whatsoever to get it back through the hatch

and there was also an old telly - sort of 1960s vintage - that was way too big
and yet it had to be the original hatch

so - the only possibly thing is that the shrink

 

[Ming the Merciless]

I see disc brakes continue to be maintenance free.

[ducks for cover]

With rim brakes you’d also be measuring the rim to work out your wheels will collapse into mini black holes after 7,341.23812345619 miles.