Jobst

Tom said:

I mean, we've seen carbon rims and sandpaper-like brake shoes. We've
seen those roller cam brakes designed by ham fisted machinists instead
of mechanical engineers.

I like roller cam brakes a lot. The Nexus kind. ;-) It was likely
designed by folks that actually use their bikes to fetch their kimchee
and gouda, and happended to be engineers, vs folks looking for uber
braking. Personally, I'd like to see Shimano and Sram put out some disc
brake compatible internal hubs, as I think discs are a perfect
compromise between the reliablility of roller cam/drum and actual
decent braking performance.

Likely, you're referring to the roller cam cantis of the late eighties.
Those and the canti u-brake were indeed a [censored] to set up, and stupidly
located under the chainstays. I liked them on city bikes where you
didn't want your rack and load to interfere with your brakes, but I
didn't like setting them up. fiddly.

I was told that when we all went from MA40s and MA2s to CD4s, the Delta brakes didn't work on the narrower rim

true? 🙂

Tom who? said:

Jobst, now that time has passed and I'm sure you've seen some pretty
horrible ideas go through the mill, do you still believe that Campy
Delta brakes were such horrible things?

I take it you missed the reasons why this brake was dumped. Enough
people crashed on them to get rid of the hazard. An accelerating
mechanical advantage as brake force is increased is a killer,
especially in the wet when the brake must be pressed far harder than
when dry and the transition to a higher mechanical advantage can lock
the wheel.

Quoted message said:

I mean, we've seen carbon rims and sandpaper-like brake shoes.
We've seen those roller cam brakes designed by ham fisted machinists
instead of mechanical engineers.

Forget about wear problems, it's a control problem. As dearly as
equipment enthusiasts and symmetry aficionados loved the brake, it was
a classic misunderstanding of brake design.

Quoted message said:

We've seen so many bad ideas that were ONLY bad ideas and like the
Campy Delta brake passed on with the times.

Quoted message said:

My point then and now was pretty much the same - bad ideas are bad
ideas, not serial murderers waiting to strike. I tried your
descending techniques and could never hope to match your crazy
cornering speeds. Does that mean that your bike was better than
mine?

I don't understand your question. What is it about descending that
you don't understand? It takes good brakes and tires, and of course a
good fit to the rider. The rest is skill.

Jobst Brandt

I tried your descending

Quoted message said:

techniques and could never hope to match your crazy cornering speeds.
Does that mean that your bike was better than mine?

if you want to be an organ donor some day, keep trying match his descent
speeds.

Quoted message said:

Tom who? writes:

Who cares "who", Jobst?

Quoted message said:

Quoted message said:

Jobst, now that time has passed and I'm sure you've seen some pretty
horrible ideas go through the mill, do you still believe that Campy
Delta brakes were such horrible things?

I take it you missed the reasons why this brake was dumped.

Four reasons that Deltas were discontinued:

1) They were "too heavy" for the weight weenies.

2) They were "too expensive" to produce.

3) Their virtues (wonderful modulation in the hands of a skilled rider,
assuming proper adjustment) went under-appreciated.

4) The market demanded "something new".

IMO, YMMV, etc., etc., etc.

<remainder of post snipped>

531Aussie said:

I was told that when we all went from MA40s and MA2s to CD4s, the Delta
brakes didn't work on the narrower rim

true? 🙂

--
531Aussie

Not true, last gen Deltas(like I have and use everyday), had two sets
of washers to move the blocks in or out for 20mm to 25mm rims.

I was riding down the very nice descent from the top of Fairmont Ave.
in San Leandro towards town. I was on my touring bike with cantilever
brakes on it. It was pouring rain. I got a little nervous that my speed
was getting higher than I'd be able to control so I put the brakes on a
bit. Nothing. I put them on a little harder, nothing, Harder still and
I noticed a funny noise. I looked around and didn't see anything. I
looked down and noted that both wheels were locked up and I was sliding
on the wet asphalt. I released the brakes and was more careful.

The moral of this story is that you can lock up the brakes under poor
conditions with any brake.

I completely understand that you're saying that these things happen far
easier with Delta brakes because of a mistaken design philosophy and I
also understand that you're complaining that this was so far off the
chart that even the most expert of riders couldn't predict nor control
it.

But in fact most of those Delta brakes didn't go to people who would
ever use them up to or near their limits and never caused the slightest
concern to these people.

You were involved in the design of the Avocet tires I believe. Those
were the longest wearing and best traction tires of the time and I
generally got 30% more wear and never had a traction problem with them
that was fairly common with other tires of the time. Today most tires
are constructed on the lines of your original designs.

My whole point is that times change and things tend to select for the
better working components. It doesn't go in a linear progression
though. I'm sure that you'll admit that for racing the present Ergo
levers are impossible to beat. But lately I've been rather scandalized
at the cost of these components and I've been setting up newer bikes
with Shimano rear derailleurs and barend shifters. I find that they
work very well and have a lot of advantages not the least of which is
that they're about 25% of the cost of Ergo.

So I'm using less than optimal components just like some old fart I
watched pass me on Kings Mountain Rd riding up hill in something that
looked like a 44-19 one day. There is absolutely no way that you can
justify using that sort of gearing except to say that you prefer it.
Some people prefered Deltas and they never had problems.

You were right to criticize them and I believe I was equally right to
point out that Deltas were not evil, only sub-optimal.

If you want to be an organ donor try to match his climbing gears......

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

I like roller cam brakes a lot. The Nexus kind. ;-) It was likely
designed by folks that actually use their bikes to fetch their kimchee
and gouda, and happended to be engineers, vs folks looking for uber
braking. Personally, I'd like to see Shimano and Sram put out some disc
brake compatible internal hubs, as I think discs are a perfect
compromise between the reliablility of roller cam/drum and actual
decent braking performance.

The roller brake on my Nexus 7spd hub sucks. I can pull the brake as hard
as I can and it still won't hold. The only good thing I can say about it
is that I never have to worry about locking up that brake. Luckily my
front brake is an Avid mechanical disc. Works very well.
--------------
Alex

Tom said:

But in fact most of those Delta brakes didn't go to people who would
ever use them up to or near their limits and never caused the slightest
concern to these people.

You may not plan on using them at their limit, but what happens in an
emergency when you have to? If can't achieve maximum safe braking in a
predicable (linear) manner, you're probably going to crash.

Art Harris

Crescentius Vespasianus said:

if you want to be an organ donor some day, keep trying match his descent
speeds.

I've managed over 57mph round here, where we don't have mountains, just
the occasional 16% hill.

Pork Hill on Dartmoor, UK is reputed to be good for over 70mph, having
the holy trinity of a steep gradient, gentle curves and good smooth
asphalt. I got up to 56mph until I caught up with a car and had to
brake, and I didn't have the energy to haul myself back up for another
attempt.

At that speed it's more like driving a car; the hedges fly by at a rate
you don't normally see on a bike, and the road buzz largely fades out.
Because of this it's not especially scary - just try not to think about
the stopping distance, or how far you would sail through the air if you
hit something.

Fortunately the cattle grid at the top of the hill keeps stray sheep off
the fast part!

Zog The Undeniable said:

Crescentius Vespasianus said:

if you want to be an organ donor some day, keep trying match his descent
speeds.

I've managed over 57mph round here, where we don't have mountains, just
the occasional 16% hill.

Pork Hill on Dartmoor, UK is reputed to be good for over 70mph, having
the holy trinity of a steep gradient, gentle curves and good smooth
asphalt. I got up to 56mph until I caught up with a car and had to
brake, and I didn't have the energy to haul myself back up for another
attempt.

At that speed it's more like driving a car; the hedges fly by at a rate
you don't normally see on a bike, and the road buzz largely fades out.
Because of this it's not especially scary - just try not to think about
the stopping distance, or how far you would sail through the air if you
hit something.

Fortunately the cattle grid at the top of the hill keeps stray sheep
off the fast part!

It's not the speed downhill in a straight line that's important, when
trying to follow someone down hill. The place where you pucker is in
the corners. And Jobst believes, as an engineer, that if a tire has
been tested to have a slip angle of 45 degrees, that cornering at 44
degrees is not only sane, but safe. And he does it (okay, maybe 41
degrees). I've done a couple descents with Jobst and was flat out
dropped in a couple corners, and I'm not a slow descender.

In the bay area, a friend of mine (Dave Stahl) had the "7 minute club"
descending Kings Mountain Road. He did 6:58, I was unable to make it
and did 7:05. Not sure how fast Jobst would go down that hill, but he
pedaled in the straights I'd wager sub 6:50. Absolutely no way to go
that fast without some real "balls out" cornering and a clean road.

I'll bet I'm a member of the 10 minute club and I'm faster than most.
I've seen too many cars pull out on that road, watch guys go down in
the corners by losing traction and I even watched one cyclist pass a
car on the hairpin on the inside at 30 mph! That scared me so badly
that I rounded the corner at about 5 mph only to have a blowout as soon
as I pulled the bike upright. Turned out to be a sidewall cut in a
Continental Gran Prix.

I more or less draw the line at about 40-45 mph depending on sight
lines.

Art Harris said:

Tom said:

But in fact most of those Delta brakes didn't go to people who would
ever use them up to or near their limits and never caused the slightest
concern to these people.

You may not plan on using them at their limit, but what happens in an
emergency when you have to? If can't achieve maximum safe braking in a
predicable (linear) manner, you're probably going to crash.

Art, with respect, have you ever actually used Deltas?

IMHO, much of the perceived problem with Deltas came largely in the
startling transition from the previous Campy brake calipers (NR/SR,
etc. - all basically variations on the Mod. 2040 sidepull introduced in
1968). The old Campy brakes required a good hard pull to get a good
firm stop. The Deltas were quite different, with their "progressive"
action. It took some getting used to.

I wonder how Campy's current dual-pivot and "differential" (dual-pivot
front/single-pivot rear) brakes would be received by the Campy faithful
if they were introduced as the direct successors to the NR/SR brakes in
1984. Would they be percieved as "touchy", "too sensitive" and prone to
wheel lockup?

Another problem, of course, came from poorly set up Deltas. But that's
another story.

Tom said:

I'll bet I'm a member of the 10 minute club and I'm faster than most.
I've seen too many cars pull out on that road, watch guys go down in
the corners by losing traction and I even watched one cyclist pass a
car on the hairpin on the inside at 30 mph! That scared me so badly
that I rounded the corner at about 5 mph only to have a blowout as soon
as I pulled the bike upright. Turned out to be a sidewall cut in a
Continental Gran Prix.

I more or less draw the line at about 40-45 mph depending on sight
lines.

Without timing, you'll never know. I'd consider 10 minutes awfully slow.

I've maybe gone 40 mph on a couple of the straightaways, but there's
only one place to go that fast. And 8 1/2 minutes can be achieved by a
couple good accelerations out of corners. But absolutely no need to do
stuff utterly stupid like pass a car on a hairpin on the inside at 30
mph.

We're talking about descending fast and cornering somewhere near the
traction limits, but not a Chinese Downhill.

On 3 May 2006 09:03:37 -0700, "Tom" <[email hidden]> wrote:

snip

Quoted message said:

I looked down and noted that both wheels were locked up and I was sliding
on the wet asphalt. I released the brakes and was more careful.

snip

So you locked up the front wheel and didn't notice until you looked?
I'm having a real hard time with that one...