Dutch Roll

Ron Hardin said:

I observed, pedalling home with 40 pounds of Snapple on the back and
20 pounds in the front basket, that the bike has a Dutch Roll tendency,
a long-period drift left and right, when coupled with my natural
bike riding reflexes. I wonder what causes it.

I'd speculate it's the Snapple.

Ron Hardin said:

I observed, pedalling home with 40 pounds of Snapple on the back and
20 pounds in the front basket, that the bike has a Dutch Roll tendency.
....
Transport aircraft have yaw dampers to reduce it. I wonder if they
make them for bikes.

Having an affection for rather unusual bicycles, and the desire to use
them as practical transportation (which means having cargo capacity),,,

I'm thinking that a large front-mounted basket is the best way to carry
very-light items, and a trailer is the best way to carry very-heavy ones.
~

On May 18, 5:14 pm, Paul Cassel <[email hidden]>

Quoted message said:

Ron Hardin said:

I observed, pedalling home with 40 pounds of Snapple on the back and
20 pounds in the front basket, that the bike has a Dutch Roll tendency,
a long-period drift left and right, when coupled with my natural
bike riding reflexes. I wonder what causes it.

I'd speculate it's the Snapple.

/snort

Kroger brand loose tea weighs 12 ounces for a can and makes a hundred
glasses. If you're not man enough to drink it straight, add some Peach
Flavor Aid*.

*preferred by 7/10 Guyanans

Paul Cassel said:

Ron Hardin said:

I observed, pedalling home with 40 pounds of Snapple on the back and
20 pounds in the front basket, that the bike has a Dutch Roll tendency,
a long-period drift left and right, when coupled with my natural
bike riding reflexes. I wonder what causes it.

I'd speculate it's the Snapple.

Watch out for that Snapple

http://www.nytimes.com/2007/05/18/nyregion/18snapple.html
(registration may be required)
--
JT
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"landotter" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On May 18, 5:14 pm, Paul Cassel <[email hidden]>

Quoted message said:

Ron Hardin said:

I observed, pedalling home with 40 pounds of Snapple on the back and
20 pounds in the front basket, that the bike has a Dutch Roll tendency,
a long-period drift left and right, when coupled with my natural
bike riding reflexes. I wonder what causes it.

I'd speculate it's the Snapple.

/snort

Kroger brand loose tea weighs 12 ounces for a can and makes a hundred
glasses. If you're not man enough to drink it straight, add some Peach
Flavor Aid*.

Better yet, just grab some peach nectar to add to the tea. Comes out
tasting way better than any of those freaky Snapple flavors.

Greg
--
"What have you got in that paper bag?
Is it a dose of Vitamin C?
Ain't got no time for Western medicine
I am Damo Suzuki" - Mark E Smith

do you know "french heel" ? good excercise for anti-cramping.
the FH website may have gone by the wayside.

In article <[email hidden]>,

Ron Hardin said:

I observed, pedalling home with 40 pounds of Snapple on the back and
20 pounds in the front basket, that the bike has a Dutch Roll tendency,
a long-period drift left and right, when coupled with my natural
bike riding reflexes. I wonder what causes it.

It's probably a symptom of something slightly loose on the rear
carrier.

Possible, but in these circumstances the first suspect is typically the
nut between the saddle and the handlebars.

Quoted message said:

Transport aircraft have yaw dampers to reduce it. I wonder if they
make them for bikes.

Well, you've got a higher polar moment of inertia than before, but I
suppose that what's most likely is that having a heavy load on both
sides of the hinge in the middle of the bike (that is, the headset) may
be the trouble.

I'd consider trying two things: vary your cadence and see if that has an
effect, and move the load around to see if things get better or worse.

--
Ryan Cousineau [email hidden] http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

"Ryan Cousineau" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In article <[email hidden]>,

Ron Hardin said:

I observed, pedalling home with 40 pounds of Snapple on the back and
20 pounds in the front basket, that the bike has a Dutch Roll

tendency,

Quoted message said:

Quoted message said:

a long-period drift left and right, when coupled with my natural
bike riding reflexes. I wonder what causes it.

It's probably a symptom of something slightly loose on the rear
carrier.

Possible, but in these circumstances the first suspect is typically the
nut between the saddle and the handlebars.

Quoted message said:

Transport aircraft have yaw dampers to reduce it. I wonder if they
make them for bikes.

Well, you've got a higher polar moment of inertia than before, but I
suppose that what's most likely is that having a heavy load on both
sides of the hinge in the middle of the bike (that is, the headset) may
be the trouble.

I'd consider trying two things: vary your cadence and see if that has an
effect, and move the load around to see if things get better or worse.

--
Ryan Cousineau [email hidden] http://www.wiredcola.com/

I can remember carrying groceries on the back of my bike on an old
Pelissier bike rack and cheap old panniers. The rack would start ocilating
side to side on any downhill sections of my trip if I got over about 15
MPH. I fixed the problem by reinforcing the rack mounts to my frame and
the rack itself.

Maybe the OP's racks are not firmly attached to his bike.

Chas.