Shimano finned brake pad orientation ?.

Does it actually matter?

Front – the fins are horizontal

Rear – the fins are vertical

Ultegra with stock pads, FWIW. I think I’ve mounted them as per the instructions but now I’m doubting myself 🙄

I guess the calipers themselves are mounted in different orientations and the pads aren’t sold as front or rear specific means no problem..?!

I guess the calipers themselves are mounted in different orientations and the pads aren’t sold as front or rear specific means no problem..?!

Correct. The pads are in the same place relative to the caliper, it’s just the caliper is further round the rotor.

The pads only fit in the caliper in one direction so you can’t get it wrong.

Top tip – take out those slot headed retaining screws before they seize then round off, and replace them with either split pins or a hex headed version from MTB brakes.

I find them a tricky bugger to fit!

I find them a tricky bugger to fit!

Really? How so? I fitted some for a friend the other day and it took seconds!

BTW the Shimano ones have L and R printed on the inside edge so you know which way round to put them for sure.

Do the fins actually make any difference?

Do the fins actually make any difference?

Yeah they make the brakes 100% more rattley. I replaced mine with non finned (non rattley) pads when the time came.

The pads only fit in the caliper in one direction so you can’t get it wrong.

No they don’t and those (on the rear) of the OP are upside-down, the little nodule on the pad goes above the retaining screw, the fins apparently channel the air flow that passes over the chain-stay onto the braking surfaces.

Mine are marked L and R.

They’re all marked L&R. OP has his correct.

See 105 R7000 caliper (same forging as Ultegra) pictures here :-

https://bike.shimano.com/en-EU/components/road/category/brake.html

No they don’t

Oh it’s a road caliper. Only looked on my phone with half asleep eyes.
All the MTB finned pads 2 and 4 pot will only fit in one direction no idea about road brakes.

Friction material always facing the rotor.

take out those slot headed retaining screws before they seize then round off, and replace them with either split pins or a hex headed version from MTB brakes.

Or! put a dab of grease on the retaining pin and don’t do it up too tight. In all the years I’ve had disc brakes I’ve never had one anywhere near size up. And split pins look shit (which is why they are only on Deore and lower).

Ooh, I’ve got top-tip – if you lose the retaining clip off the end of the pin, replace it with a cable donut. 😀

Ref fins – does make me wonder how the cooling works. I’m not an engineer, but everything about this pic tells me that the fins have no effect. The airflow should be directed towards the pads by the fins, shorely?

Or! put a dab of grease on the retaining pin and don’t do it up too tight. In all the years I’ve had disc brakes I’ve never had one anywhere near size up. And split pins look shit (which is why they are only on Deore and lower).

Woooah hang on there, you’re expecting the average forum dweller not to be a ham-fisted nugget 😀

I do exactly the same, dab of grease on thread of the screw – while not simultaneously daubing it all over the disc and pads – and then just nip it up slightly, low and behold, they come out again and don’t fall out, even on my MTB with XTR brakes, amazing innit!!

I is amazed! 😀

I’m not an engineer,

That much is clear!

but everything about this pic tells me that the fins have no effect.

Nope, they increase the surface area of the backing plate and will therefore dissipate more heat via both convection and radiation. The heat travels by conduction from the pad to the fins.

Exactly the same as the fins on the casting of an air cooled engine, they act as a radiator rather than directly air towards the piston.

Ref fins – does make me wonder how the cooling works. I’m not an engineer, but everything about this pic tells me that the fins have no effect. The airflow should be directed towards the pads by the fins, shorely?

It’s designed to dissipate heat being conduced through the backing plate.

The hot bits are on the inside between the pads so they could never really work as ducts. You could probably mold something that sat just below the caliper on the wheel side to force a little more air against the disk, but I can’t see it having an impact. Ducts work in F1 because the disk gets no airflow otherwise. On a bike the whole disk is spinning in free air so the problem isn’t needing more air, just better transfer.

Pads on the other hand get warm as they’re surrounded by the caliper. And unlike motorsport you can’t reliably expect them to stay at an operating temperature because there isn’t that consistent hard braking every few seconds. So the ideal scenario is a pad that works from cold, and trying to keep it as cold as possible.

Or! put a dab of grease on the retaining pin and don’t do it up too tight

Please tell the muppet who assembled my bike in the factory. After a fair few km on mucky roads there was no way that screw was moving without a fight.

Give me his address!

Exactly the same as the fins on the casting of an air cooled engine, they act as a radiator rather than directly air towards the piston.

Ah! Cool (literally). Back in me box then.
I do still stand by my cable donut tip though 😀

correct.

See 105 R7000 caliper (same forging as Ultegra) pictures here :-

https://bike.shimano.com/en-EU/components/road/category/brake.html

Ah,yes that’s pretty clear. Panic over 😃

@steve_b77

The pads only fit in the caliper in one direction so you can’t get it wrong.

No they don’t and those (on the rear) of the OP are upside-down, the little nodule on the pad goes above the retaining screw, the fins apparently channel the air flow that passes over the chain-stay onto the braking surfaces.

Seems you have your pads on the wrong way around (assuming that KTM is your bike) though they do look slightly more aerodynamic in that position, and it’s all about aero these days 😉