On Saturday, November 11, 2017 at 10:47:10 AM UTC-8, Joerg wrote:
On 2017-11-11 08:59, jbeattie wrote:
On Saturday, November 11, 2017 at 8:34:13 AM UTC-8, Frank Krygowski
wrote:
On 11/11/2017 10:37 AM, Joerg wrote:
On 2017-11-11 07:21, jbeattie wrote:

... I don't think most people need discs with giant rotors, but
Joerg is a special case.


All one has to do is go down French Creek Road and then Holly
Drive out here on a loaded bike and the li'l 6-incher in back
starts to smell. Can't use the front too much because it's loose
gravel. Similar for some of the long hills in the Sierra east of
here. The 8" rotors I mounted yesterday will allow me to roll
down many of the long downslopes without a cooling-off break or
spritzing water onto the rotors.

A friend had 8" on the front and still lost the front brake at
the last curve on a long hillside. One of those "Oh s..t!"
experiences.

Hmm. So even 8" isn't sufficient. Good to know.

My brakes are about 25" diameter. I'm keeping them! ;-)

In Joerg's neighborhood but much further into the Sierra, I did
Monitor Pass, Ebbetts, Carson and Luther multiple times on loaded and
unloaded bikes with either single pivot Campy NR or Mafac cantis.
Tioga, too. Ebbets has some 20% pitches. I never once had brake
problems.


Very different scenario because there you can just "let'er rip" most of
the time. I described a road that has a long downhill stretch and is
gravel. You have to hold the brakes the whole time because there is
forest left and right. Sure enough about 70% down a Shepherd and a
smaller dogs came out of the woodwork and were totally unfazed but my
brightly lit aluminum horse. They sauntered across. At 40mph that would
have been a nasty crash. At 15mph I could even greet the dogs properly.
There are also diagonal ruts and washouts that you won't see in time at
high speed. A reminder could be seen in one curve where a car driver
must have thought differently, flew off the road and chopped some trees.
The wreckage was already hauled off but there still was a torn-off front
axle and a ripped out coil spring way out in the bushes. Ghastly.

Actually, you can't let 'er rip down Ebbetts. My son, who is about 200lbs, 6'5" and basically all leg muscle, descends Guardsman's Pass on CF rims and caliper brakes. https://www.youtube.com/watch?time_c...&v=hRM3bFXlyNk https://www.youtube.com/watch?v=NKdVMYo1H38 Basically the whole world descends much hairier descents than French Grade Road on pretty mundane equipment. Having forest to the left and right is basically SOP around here. I could commute to work on Fire Lane 5 if I were so inclined. https://www.youtube.com/watch?v=XbWCFwIxgnw&t=62s (on a CX bike). It gets nasty at 3:00. Anyway, get to the bottom, turn right and you're practically down town. I've done that on a SuperSix.

Speaking of climbing, my son's friend Luke did an Everest the other day -- almost 34,000 feet in 120 miles in 11 hours. 100 times up an 11% neighborhood road in the upper Avenues in SLC. The guy is a phenom. He's on track for over a million feet of climbing this year, and he was off his bike due to a serious injury for a month. His last Everest was up every canyon in SLC, including the Midway side of Guardsman Pass, which is one of the most difficult climbs/descents in the US. All on caliper brakes. Yes, it's not Cameron Park, but still some serious climbs.

-- Jay Beattie.