Brake Performance

It's all in the physics.  Its the friction that stops you and you need more friction to stop a heavier object when compared to a lighter object at any given speed.  Throw in some moisture and the same rules apply but the friction forces drop off.

The ability to apply the force comes from you brake set up - calipers, cables, leavers and pad alignment.  The friction is largely governed by the type of friction surface, i.e. pad material and rim, and of course the surface area.

I concur with pretty much everything people have said so far.  Regardless of your equipment quality the results will be better if everything is set up correctly.  I've experimented with various pads and claipers over the years and tried toe in versus flat pad and to be honest I've only found 2 things have ever had any significant impact, especially in wet conditions.  A good quality softer pad always seems to offer better wet weather performance, but they wear out more quickly in the dry (incidentally I ran some DA pads with aluminium rims and they were aweful in the wet.  Very gritty and covered the rim with grey mush which looked like aluminium filings..!).  Secondly, pad size has a (relative) massive impact.

I've run Reynolds Assult carbon wheels and the wet weather braking was just plain scary.  They force you to use the Reynolds pad, but they also offer some that are (I think) 44% larger surface area and when I switched to these I immediately noticed the better performance in both the wet and dry.  Of course, this is simply the physics in action.

Just recently I've got a new bike with proprietry calipers (Trek) and these seem to lay the pad very flat on the rim.  Coupled to this I have Zipp 404 NSW wheels that use their new braking surface with visible profiled surface and complimentary pads.  They claim these will out perform the best aluminium rims for any given brake set up and having riden them in the dry so far I can confirm they are a revaltion when compared to all my previous rim brake experiences.  In fact, I've had the rear wheel skipping around several times without trying too hard.  I'm also expecting the pads to wear quickly and to be stung when buying new ones.

My simple conclusion would be to try and maximise the performance through set up and pad choice, however rim brakes will always be compromised in the wet when compared to disks.  Of course if you run disks in the wet you simply move the friction problem from the rim to the tyre contact.  Best advice is to maximise the set up of whatever kit you have and tailor your riding to the conditions and try to keep it rubber side down..

have you tried changing the cables

Never underestimate the importance of good cables when it comes to good braking. 

I'm not talking about spending a fortune on fancy cables, but making sure the cables you are using are a good quality and in great condition. 

Personally, I find stock Campagnolo cables to be a bit better than shimano, but its pretty close. 

Other than that, the quality of your caliper will make the biggest difference. 

Both of the above are related to inherent friction in the system; the greater the resistance, the lower the overall brake power. 

Brake pad set up is also important, I set my pads to land square on the rims... no toe in at all. This means less modulation, but the big plus is that you gain more ultimate stopping power. 

As for pads themselves, I've found the difference between different manufacturers to be where they sit on the spectrum of wear rates and ultiamte power. Softer pads seems to equal better stopping, but less durability. 

I'd rather buy more pads that wear out quickly, than a more expensive harder wearing pad that lacks ultimate power. 

"And make sure they are adjusted right up, the greatest leverage is at the start of the lever's travel"

I find the opposite; if I adjust the brakes so the blocks are very close to the rim, I find it harder to pull the lever.  Better to back them off a bit so there's a bit of lever movement before they start to bite.  May be something to do with hand size / strength, and where in the gripping movement you can apply the most force?

I'm puzzled by your comment about fitting 105 brakes then upgrading the blocks to Dura Ace.  As far as I can tell from Shimano Tech Docs the very same cartridge holders and pads are specified in 105, Ultegra and Dura Ace...

I've just fitted some used 5800 calipers with their stock brake blocks to my summer bike and find them outstandingly good compared to the Tiagra calipers they replaced.  So much so that I bought some 5800 cartridge holders and pads for the winter bike too.

i'm a larger rider as things go, 6'5 and ~108kg just now + backpack. i have a cube cross converted to flat handlebar with shimano zee brakes and 203mm rotors front and back.

depending on road conditions the rear brake is crazily overpowered, and maybe the front too. 180f/160r would probably be a better balance but i'm leaving it as-is as its what's there and it works. the big rear works well as a drag brake on the long descents when i can put the weight back there though.

the flipside is that there has never been a moment where i've felt i won't be able to stop in time.

I'm a bigger rider. 92kgs recently, but going back down to 80 atm. 

Upgraded my brakes to Dura Ace. Pricey, but wow, what a difference over Ultegra. I will never ever go to a lower brake set again. No clue how it makes such a big difefrence, but it's amazing. I bomb about way faster now on downhills and corners. Even about town I can stop on a dime. Loving it.

Have another Sora bike here, had to stick SwissStop greens in and toy with them to get any real breaking for the missus, but poor brakes are poor brakes. Way more to it than just the pads. 

If you have cash to throw at your bike, say 150quid. I'd get the DA brakes, then take them off again and stick on a new bike later. 

When I upgraded to 105 brakes, I found the standard pads worked ok but were picking up loads of bits of aluminium from the rims. I switched to Kool Stop dual compounds and they seem much kinder to the rims with more feel too.

Tbh, the stock Tektro pads are frigging lethal in wet weather. Should be the first thing in the bin with any new bike.

Big +1 for green swissstop pads and adjusting toe-in. If you are worried about cost they seem to last ages and I noticed a big difference on my tektro brakes when I upgraded. 

Another vote for Swissstop Green pads. My winter bike with calipers and Greenstop pads brakes as well in the wet as my disc bike, they're that good.

There is a huge leap in performance from 105 to dura-ace. If it's pure performance you're after, I'd recommend duraace, and then experiment with different brake blocks. I use duraace blocks and notice little difference in the wet and dry, but I'm only 79kg

I fitted swissstop pads and upgraded the brake cables on my cheapy road bike and that improved the braking significantly. The cable outers on bottom of the range bikes aren't that great and decent compression less cables like shimano sp41 or Jagwire racer pros can make a big difference 

I think you should look seriously at some really good brake blocks, they genuinely do make a deal of difference.  And make sure they are adjusted right up, the greatest leverage is at the start of the lever's travel. 

I would rather run Tektro brakes with genuine Campag' blocks than genuine Campag' brakes with Tektro blocks.

Your a really big guy, I think you'll need ABS when they invent or develop it, if they haven't already dunno! 

Rough your blocks up with some sandpaper