If it helps, I had alloy wheels when riding the Colorado mountains. I will also add that possibly due to technique, my disc -equipped friends run out of brakes before the end of a technical descent. We have steep roads in Greece, never had a problem, even when flirting with 80kph/50mph.
I rode a rented Colnago with discs to Stelvio. LOTS of braking power, but very binary (on /off) performance. Frankly, I missed the modulation of my rim brakes during the fast descent from Lagi di Cancano. And because it was a misty rain, I did have to pump the brakes , to dry the discs before they worked normal.
Rim brake calipers: I felt a noticeable difference swapping calipers from Ultegra 6800s to 8000s. Much stiffer. I was able to set up the levers closet for someone who wanted a shorter reach.
The 8000s and later(and corresponding 105s and Dura-Aces) have a steel bridge between the pivots and beefy arms. I think the performance is well worth the slight weight increase.
Hmmm. I had no issues at all with Campy Skeleton brakes. When I was running them, I never had any moment when they felt lacking. I didnât feel like they were lacking anything compared to Shimano or SRAM rim brakes at the time.
As for disc brakes, my Campy disc brakes are my favorite brakes of all time. Their modulation suits my tastes and reminds me of the modulation of disc brakes on motorcycles Iâve raced. Thereâs no step function like behavior, i.e. no binary-eque feeling at all.
IMHO, if someone is running out of brakes on a descent, itâs almost always due to technique, specifically dragging the brakes. That applies to be both rim brakes and disc brakes. Thereâs a long history of people melting rim brake pads or glazing disc brake pads on long or steep descents. I think there was gran fondo in California (maybe it was Levi Leipheimersâs) that warned riders, especially those with CF rims, about the heavy braking required for one particular descent.
As for riding in the rain both disc and rim brakes will need to clear water before they achieve max power. I do think rim brake tracks can take more time clear since theyâre much closer to the road and will likely see more water (and possibly contaminants) splashed onto them.
Worst brakes ever? Zero Gravity 0G-05. Those were horrible.
Totally nonscientific but in my long experience kool-stop salmon pads on alloy rims with good direct mount calipers worked just fine in the rain, if you were willing to burn through a set of rims every winter.
I have a totally different experience; quite cheap brake pads work way better on alu rims than even Black Prince on my (Fulcrum) carbon rims in the rain and even on the dry for absolute stopping power. You might be an instructor but thatâs a false claim.
I tried the cheap pad option, along with the Shimano âfactoryâ break pad option. Minimal modulation and almost binary braking. Very little feel of what is happening. With a good brake pad, it is possible to instigate understeer, as too much of the traction goes towards braking (not enough left over for turning, the âCircle of Frictionâ is one reference about this. https://www.researchgate.net/post/What-is-Circle-of-Friction)
Yes, discs do get wet. Rain droplet size and density of rain volume is different, depending on oneâs locale. Misty rain will wet the discs and thus need drying them out. Especially when one brakes sparingly and does not keep dragging the brakes.
Finally, you are absolutely correct about hot discs not needing to dry out. Rims getting hot from rim brakes? Yes, happened to friends with poor braking technique, to the point of blowing up a tube (again, due to dragging the brakes). Have I tried disc brakes myself? Certainly, ever since 2004, hydraulic discs on my daily commuter.
I live in Belgium and have biked in quite a lot of different countries in the rain, never had a problem braking with disc same with my friends with discs (with different levels of descending ability)
Of course they get wet but not to the point that you have to âlet them dryâ (unlike with carbon rims even on flat terrain)
No experience with cheap brake pads on alu rims (sorry ;)) but otherwise I concur 100%. Black Prince on Shimano carbon wheels (tubular back then) or Campa red on Campa / Fulcrum wheels (even the most recent Bora WTOs) arenât better than good pads on aluminium rims.
And discs offer heaps of extra braking power even in the dry.
What I find is that when the discs are wet (mist or rain), they need a few rotations to dry and give more braking power (like rim brake) and the difference in performance is higher than what it is with good rim brake pads (like Koolstop Salmon) and alu rims. But the absolute braking power of discs remains vastly superior.
Hmm, very interesting. So youâd say it would be worth to change a set of 5800 Shimano 105 rim brake calipers to 105 BR-R7000 or ultegra BR-8100? Struggling a bit with braking power on a carbon Campy wheelset as compared to my gravel bike with discs.
Iâd go for the 8100s. I was wrong about the 7000s. They look the same as the 8000/8100 but lack the steel brace between the pivots. (Really, Shimano?)
I could feel the decrease in flex when I swapped from the 6800s. Much more solid feel at the lever.
I doubt youâd notice any significant difference; IME the 5800s are fine. The only real differences with the newer calipers are:
The Q/R is either on or off, no in between
Thereâs less tyre clearance inside the caliper, especially laterally
The brake feel at the lever is firmer, not necessarily a good thing IMO
On the other hand, older (pre-7900) calipers and levers have different MA and cable pull, and the two generations donât play well together. (I personally prefer the older brakesets but YMMV.)
As for discs versus rim brakes, lots of anecdotes and tired opinions above but no data.
