Downhill speeds...or: I must be getting old - Page 3

On Wed, 30 Jun 2004 02:29:19 GMT, "Leo Lichtman" <l.lichtman@worldnet.att.net>
wrote:

>
>"Terry Morse" wrote: The best way to corner is to keep
>your body in line with the bicycle, with no extraneous
>movements. In other words, when the bicycle tilts, you go
>with it. But there is no leaning to be done. ^^^^^^^^^^^
>This is correct, and it is what you will do if you don't
>get wound up in too much "thinking." The body weight,
>together with the centrifugal force form a vector that
>must go through the line of contact of the tires with the
>road. Any fooling around you do with the angles may change
>the inclination of the tires to the road, but the vector
>still has to go through that line of contact, or you will
>not be stable.
>

If you lean your body over more in a turn then the bike
leans less, at least that's how it works on motorcycles.

Ben

"David Kerber" <ns_dkerber@ns_ids.net> wrote
>
> To help you keep good control at high speeds, you need to
> relax your grip a bit, and put a little more weight on the
> pedals (don't lift yourself completely off the saddle,
> though).

Why not lift off the saddle? I commonly descend this way,
especially if the pavement is bad, or visibility is limited
(may not see a bump coming), it's also more or less the
required way to descend off-road.

In article <bczEc.3469$XM6.3018@attbi_s53>,
peter_cole_no_spam_at_all@comcast.net says...
> "David Kerber" <ns_dkerber@ns_ids.net> wrote
> >
> > To help you keep good control at high speeds, you need
> > to relax your grip a bit, and put a little more weight
> > on the pedals (don't lift yourself completely off the
> > saddle, though).
>
> Why not lift off the saddle? I commonly descend this way,
> especially if the pavement is bad, or visibility is
> limited (may not see a bump coming), it's also more or
> less the required way to descend off-road.

I would agree with you on any kind of bumpy descent, but I
find that on smooth pavement I have better control and can
take the corners faster if I keep *some* weight on the
saddle. I'm not sure why, but I'm guessing that it helps
slow the movements of the bike just a bit.

--
Remove the ns_ from if replying by e-mail (but keep posts in
the newsgroups if possible).

Peter Cole wrote:

> "David Kerber" <ns_dkerber@ns_ids.net> wrote
>
>>To help you keep good control at high speeds, you need to
>>relax your grip a bit, and put a little more weight on the
>>pedals (don't lift yourself completely off the saddle,
>>though).
>
>
> Why not lift off the saddle? I commonly descend this way,
> especially if the pavement is bad, or visibility is
> limited (may not see a bump coming), it's also more or
> less the required way to descend off-road.

Perhaps what he meant was to not completely lose contact
with the saddle?

When I lift off the saddle at speed, I keep contact with my
thighs to give it side-to-side stability. If I don't do
that, the bike feels more squirrely.

--
--------------------+ Frank Krygowski [To reply, remove
rodent and vegetable dot com, replace with cc.ysu dot edu]

David Reuteler writes:

>>> Anyway, a little more context from the OP would be
>>> useful. Like, for instance does he live in Kansas or
>>> western Colorado.

>> That makes no difference. The mechanics of it are the
>> same and I am sure that riding a criterium in Kansas (if
>> you like( is the same as riding one in Milano (I).

>> Maybe you can explain what is potentially dangerous about
>> slowing to a pace that feels safer.

> I am under the impression that taking an 18 mile steep
> mountain descent (like I have in my backyard so to speak)
> with my brakes on the whole way to keep me at a
> comfortable 13mph may not be a good idea w/r/t overheating
> my brake pads.

What do you call steep? A 6% grade (judging from your
numbers) is not enough to cause a problem regardless of its
length. Controlling speed to 13mph on even steeper grades
does not require a lot of braking although steep roads can
do that. The one pictures is 10% and steeper in places, and
average speed is not 30mph.

> That situation is not likely to affect someone in Kansas
> and your brakes aren't likely to fade for that reason in a
> crit no matter your locale.

I don't think you'll find "brake fade" a problem with
any descent because that would occur at temperatures
that no tire and tube would survive. You make this sound
so daunting.

I don't think the writer is planning a descent of the
Stelvio or the Mortirolo soon. Mt. Evans is a mild descent
in comparison.

Jobst Brandt jobst.brandt@stanfordalumni.org

Peter Cole writes:

>> To help you keep good control at high speeds, you need to
>> relax your grip a bit, and put a little more weight on
>> the pedals (don't lift yourself completely off the
>> saddle, though).

> Why not lift off the saddle? I commonly descend this way,
> especially if the pavement is bad, or visibility is
> limited (may not see a bump coming), it's also more or
> less the required way to descend off-road.

I think we are discussing road riding and in that
perspective the saddle adds stability to rider position that
gets lost when standing. Unloading the saddle is not the
same thing but it has the same effect on traction. Just try
it on a road bicycle at speed (30mph+), unloading the saddle
and then standing. There is a conspicuous difference.

Jobst Brandt jobst.brandt@stanfordalumni.org

Ben Kaufman writes:

>> "Terry Morse" wrote: The best way to corner is to keep
>> your body in line with the bicycle, with no extraneous
>> movements. In other words, when the bicycle tilts, you go
>> with it. But there is no leaning to be done.

>> This is correct, and it is what you will do if you don't
>> get wound up in too much "thinking." The body weight,
>> together with the centrifugal force form a vector that
>> must go through the line of contact of the tires with the
>> road. Any fooling around you do with the angles may
>> change the inclination of the tires to the road, but the
>> vector still has to go through that line of contact, or
>> you will not be stable.

> If you lean your body over more in a turn then the bike
> leans less, at least that's how it works on motorcycles.

Tilt! Motorcycles weigh as much and more than the rider and
have far more compliant tires and suspension than any
bicycle. Beyond that, motorcycle tires have such good
traction that the machinery will drag on the ground before
the tires break out from leaning into turns. Therefore,
motorcycle racers who ride near the limit must hike out as
in sailboating to achieve a grater CG slant in curves. The
weekend warriors who shove their rear ends back and forth
across the seat are merely simulating that effect...
ineffectively, but it looks good to them. It has no positive
effect on cornering. Fast guys drag their knees on the road.

Jobst Brandt jobst.brandt@stanfordalumni.org

jobst.brandt@stanfordalumni.org wrote:
> David Reuteler writes:
>> I am under the impression that taking an 18 mile steep
>> mountain descent (like I have in my backyard so to speak)
>> with my brakes on the whole way to keep me at a
>> comfortable 13mph may not be a good idea w/r/t
>> overheating my brake pads.
>
> What do you call steep? A 6% grade (judging from your
> numbers)

how pray tell, do you get 6% from my numbers. i didn't give
you enuf information to deduce that.

> I don't think you'll find "brake fade" a problem with any
> descent because that would occur at temperatures that no
> tire and tube would survive.

errr, ok .. so brake fade, your tires disintegrate.
whatever.. both are bad things from overheating on descents.
not sure what the difference is as per this point.

i have heated up my rims pretty damn hot on long descents
with minimal braking (ie, not trying to keep a particuliarly
slow pace -- remember, we're not talking about keeping a
30mph average .. the OP didn't want to go as fast as 30mph
*PEAK*). if you're trying to say that in the real world
riding your brakes to maintain a slow speed is never without
risk then ok, i stand corrected.

> You make this sound so daunting.

your inference not my intent. i can wrap my head around an
exception without getting bent out of shape.
--
david reuteler reuteler@visi.com

David Reuteler writes:

>>> I am under the impression that taking an 18 mile steep
>>> mountain descent (like I have in my backyard so to
>>> speak) with my brakes on the whole way to keep me at a
>>> comfortable 13mph may not be a good idea w/r/t
>>> overheating my brake pads.

>> What do you call steep? A 6% grade (judging from your
>> numbers)

> How pray tell, do you get 6% from my numbers. I didn't
> give you enuf information to deduce that.

Well 18 miles and about 6000ft does that. But why change the
subject? What do you call steep?

>> I don't think you'll find "brake fade" a problem with any
>> descent because that would occur at temperatures that no
>> tire and tube would survive.

> errr, ok .. so brake fade, your tires disintegrate.
> Whatever.. Both are bad things from overheating on
> descents. Not sure what the difference is as per
> this point.

I didn't say that rims got that hot. You were the one who
brought up brake fade. As I said, such descents don't
present a thermal problem.

> I have heated up my rims pretty damn hot on long descents
> with minimal braking (ie, not trying to keep a
> particuliarly slow pace -- remember, we're not talking
> about keeping a 30mph average .. the OP didn't want to go
> as fast as 30mph *PEAK*).

So? You apply the brakes now and then, especially if there
are curves. Your scenario could be taken to be an 18 mile
straight highway. Mountain roads have other reasons for
slowing down and they aren't continuous.

> If you're trying to say that in the real world riding your
> brakes to maintain a slow speed is never without risk then
> ok, I stand corrected.

It depends on how steep the road is and whether it also
requires continuous braking. Having descended many mountain
passes in the Alps before they were paved, near continuous
braking was routine on some. Steep roads, ones that a
beginner would most likely not be on, can cause heating
problems as I have described on this forum.

Jobst Brandt jobst.brandt@stanfordalumni.org

jobst.brandt@stanfordalumni.org wrote:
> Well 18 miles and about 6000ft does that. But why change
> the subject? What do you call steep?

because it's completely tangential to the discussion.

<snip>

>> If you're trying to say that in the real world riding
>> your brakes to maintain a slow speed is never without
>> risk then ok, I stand corrected.
>
> It depends on how steep the road is and whether it also
> requires continuous braking. Having descended many
> mountain passes in the Alps before they were paved, near
> continuous braking was routine on some. Steep roads, ones
> that a beginner would most likely not be on, can cause
> heating problems as I have described on this forum.

great. then i'm right.
--
david reuteler reuteler@visi.com

In article <T23Ec.119$Bv.66472@twister.tampabay.rr.com>,
Gooserider <gooserider@mouse-potato.com> wrote:

>I'll tell you, a lot of it depends on the bike.
[snip]

It also depends on the road, especially if it's curvy. I
used to commute over a 1000' lump each way, got used to
going fast downhill. But even after 5 years of that there
were certain curves where I'd almost always brake -- just in
case of gravel or other loose junk in the roadway around the
bend. Straight roads are easier.

-frank
--

<jobst.brandt@stanfordalumni.org> wrote in message
news:k7EEc.19728$Fo4.263092@typhoon.sonic.net...
> Peter Cole writes:
>
> >> To help you keep good control at high speeds, you need
> >> to relax your grip a bit, and put a little more weight
> >> on the pedals (don't lift yourself completely off the
> >> saddle, though).
>
> > Why not lift off the saddle? I commonly descend this
> > way, especially if the pavement is bad, or visibility is
> > limited (may not see a bump coming), it's also more or
> > less the required way to descend off-road.
>
> I think we are discussing road riding and in that
> perspective the saddle adds stability to rider position
> that gets lost when standing. Unloading the saddle is not
> the same thing but it has the same effect on traction.
> Just try it on a road bicycle at speed (30mph+), unloading
> the saddle and then standing. There is a conspicuous
> difference.

I don't stand in these conditions, but I may not have any
weight on the saddle, hovering an inch or so above it. I
don't recommend this as a standard technique, but as I said,
it's useful when the surface or visibility is bad.

"David Reuteler" <reuteler@visi.com> wrote in message
news:40e22b96$0$30609$a1866201@newsreader.visi.com...
> Hunrobe <hunrobe@aol.com> wrote:
> >>David Reuteler reuteler@visi.com
> > wrote in part:
> >
> >> if you drag your brakes to keep a speed you're
> >> comfortable with you run the risk of overheating.
> >> that's only
applicable on
> >>serious descents but that's where the problem manifests
> >>itself most
strongly
> >>anyway and 30mph just ain't that fast on a descent.
> >
> > This is all true but doesn't really address what the OP
> > was asking,
"Does
> > everyone get used to higher speeds?". That was the
> > question I was
addressing,
> > not "What are some of the mechanical aspects of
> > descending at speed?".
And no,
> > 30 mph ain't that fast.... :-)
>
> well, it's a bit more than just a mechanical aspect of
> descending at
speed.
> blindly telling someone to slow to a comfortable speed w/o
> that little bit of info is potentially dangerous.
>
> anyway, a little more context from the OP would be useful.
> like, for
instance
> does he live in kansas or western colorado.
> --
> david reuteler reuteler@visi.com

I live in upstate NY...no Rockies, no miles of flatland, but
some pretty good hills.

Terry Morse wrote:
>
> David Reuteler wrote:
>
> > i am under the impression that taking an 18 mile steep
> > mountain descent (like i have in my backyard so to
> > speak)
>
> Lucky bastard.

Can't you simulate the effect by using a higher gear? What
about using your brakes? Not that I understand your
affliction...

--
Cheers, Bev
oooooooooooooooooooooooooooooooooooooooooooooooooooooooo If
it weren't for pain, we wouldn't have any fun at all.

The Real Bev <bashley@myrealbox.com> wrote:
> Terry Morse wrote:
>> David Reuteler wrote:
>>
>> > i am under the impression that taking an 18 mile steep
>> > mountain descent (like i have in my backyard so to
>> > speak)
>>
>> Lucky bastard.
>
> Can't you simulate the effect by using a higher gear? What
> about using your brakes? Not that I understand your
> affliction...

what really gets ya is when you realize that going up hill
is more fun than going down. or at least as fun in a
different way.
--
david reuteler reuteler@visi.com