Heresy corner: Are we riding discs that are too big?

No matter what rotor size you have, the brakes have to absorb the same amount of energy to stop you from a given speed.

Which means that Steve above is technically correct, they both generate the same amount of heat, but don’t confuse that with temperature. Due to the larger thermal mass of the bigger disc, the temperature rise with bigger discs is less.

The main reason that people like bigger discs is to do with the lever feel while braking, as less effort needs to be put in by the rider for the bigger discs.

180/160 with sintered and 16 stone here – pads last ages.

I get through a lot of pads. I don’t think it’s to do with rotor size, or my weight particularly, and more to do with the fact that I ride through the winter in lots of mud(not that I like it, cos I don’t) which grinds all parts to a pulp in no time.

I’m 14st and ride:

FS 160/160
HT 180/160
SS 180/160

Don’t have problems with pad wear on any bike. The 160s on my FS are enough to to stop me but I prefer the aesthetics of the 180/160 combo. I’m not going to buy a new front floating rotor just for looks though. So it can stay.

As whatwouldjesusride said.

The 20p, 50p, 20p, 50p moment is your squeaky bum time as your hurtling to something you want to stop before.

Havn’t ridden for ages, went out Wednesday in Cheddar and managed to overheat my 160mm back brake – to much dragging due to fear!

H/tail 180/160
FS 160/160
Rigid h/tail 160/160

160’s are fine tbh…..

I used to run 185/165 but swapped both biks to 205/185. I weigh about 15 st and measure pad life in years. So, I’ve not actually found out what effect the bigger rotors have on pad wear. I’m expecting these pads to last well though as I had no trouble bedding them in on the big rotors.

Ha ha. Excellent. I like the pucker factor! I think when I’ve cocked it up I go straight to £2 coin and stay there… 🙂

i would have thought bigger disks would allow your pads to last longer

for the same amount of braking torque, the friction force between the pad and disc will be lower – so the pads are doing less work?

i might be wrong – i replace my pads so rarely there’s not going to be much in it!

For long descents you need something up to the job for your weight. Sintered pads are no good for long descents because the metal content promotes oveheating. Green, or even red pads are best. Gold (sintered) are designed for longevity.

I’m 16st and 165mm Hope rotors “cooked” and buckled uder the heat of an hour’s descent in the Alps. They’d return to their normal shape when cool, but these were way too small.

I then bought and fitted 185mm rotors and these were ok.

Last year I switched bikes and on this were 203mm rotors. These worked well, but still got extremely hot. The metal is permanently discoloured now.

For riding cross country in the UK, almost anything will do unless you are doing long descents.

If I had the cash for a UK only XC bike i’d fit a 160/165mm with sintered pads.

ive got 180/160 on the full sus but recently fitted 203/203 to try with different brakes and it felt great proper one finger braking i liked it im sticking with m4s 180/160 as they are good brakes and on my new ht im building im using my oro biancos with 203/203 as thats what ive got, ill prob swap to a 180 rear but the oros felt great with the 203 rotors , im 13.5 stone btw