Descending Las Flores (Santa Monica) with skills and disc brakes
 

These guys are hauling ass. Yes they did make 1 mistake in a corner (@5:17), as did I a few years ago (lesson learned). Damn I don't go this fast anymore, but watching these guys send some chill up my spine. This road has a gradient 9% avg and many sections are 12-14%.

But damn that disc brakes (of the leading rider) are annoying! Apparently his pads were shot. I've always descended this road on rim brakes.

To be honest looks pretty normal to me. Descending on those gradients on perfect dry roads, tucked in aero and pedaling 52x11 or whatever, not hard to see how you’d reach 40mph. I regularly reach those in my local hills and have done similar speeds and cornering on a 15 mile mountain descent. I feel like in the dry, carbon rim brakes don’t give up much, if any, to hydraulic discs. Some corners they get a little overconfident but not bad overall!!

These guys get KOMs on nearly every descent they film in the Los Angeles mountains - one of the most competitive cycling scenes in the continent. I would hardly qualify this as “normal”.

having done this exact ascent and descent several times, dude(s) woulda been six feet under or alive with serious injuries had a car/truck come around that bend that was overshot.
it's not exactly an uncommon occurrence for vehicles to find themselves over the line. there are plenty of people driving, cycling and skateboarding (!?) that are either waay too
confident in their abilities/machines/equipment, unfamiliar with the roads, too familiar with the roads or distracted with the views/grades in this area. i'd be pissed no end if i were ascending
las flores/hume/camino ramblas/schueren and some yahoo put my health at risk veering over the line near or into me because they wanted to push it. if it was a closed course
or (partial) one way descent without driveways like nearby tuna canyon, knock yourself out.
maybe i'm in the wrong and the only one that doesn't feel like being collateral damage regarding riders that disregard their own personal safety and, in doing so,
endanger others. too many driveways on this featured route to reasonably disregard the possibility of a car pulling in/out of a driveway descending at those speeds. even riding the brakes
until you're down to 30 mph, it takes about 3.5/4 seconds to get back up to 40 mph once you stop braking in this area. only a matter of time...

Looks like fun!

like Smashndash said, these guys are downhill KOM chasers in probably one of the most competitive KOM scene (both up and down) in the US. Pro Continental teams and some Pro Tour guys, and the Canadian cycling team, come here during the winter to train all the time. This road is not all smooth, the bends tend to have pavement rollups (due to car braking) and they can be bumpy and if you come in too hot (like they did in the video) then it's hard to brake thus forcing you to have to run wide. They're local and know every bend of the roads, and they have great skills too. The trailing rider is on rim brakes.

40+ MPH is not unachievable in my area. The distance is often too short to sustain it.

I see this, and Think I need to quit procrastinating on getting a Dash cam for my gasoline burning metal box on 4 wheels.

People do silly stuff in life, and it needs to be recorded.

Big yawn. Total idiot move at 5:31. Most turns were big sweepers. Disc brakes not needed for the minor speed reductions needed. If there were grades of 10% or more, the speeds should be higher. I hit 50-54 regularly, with a little tail wind help. No discs for me.

You know, I may not be a "downhill KOM chaser" in the biggest KOM area in the world or whatever, but I still manage to keep my bicycle within my lane, and even crazier, work with me here...

ON THE ROAD (5:17 is about as stupid as it gets).

Also, if those are truly 9-14% gradients, those guys aren't as fast as you think they are.