speed bumps/separated shoulder

Pam -

Sorry to hear you got hurt! I hope you recover quickly.

RZ

Pam -

Sorry to hear you got hurt! I hope you recover quickly.

RZ

Pam -

Sorry to hear you got hurt! I hope you recover quickly.

RZ

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

My guess... there were probably two contributing factors to your
unfortunate accident.

One, when you go over a speed bump that has enough "bump", your front
wheel's contact patch (the part of the tire actually touching the
road) will be, for a moment, forward of your steering axis (a straight
line drawn through the center of your head tube to the ground).
Normally, the contact patch is behind this axis, which results in
"trail" - and this is what makes a bike inherently stable (kind of
like a shopping cart's rear pivoting wheels). But when the contact
patch is in front of the steering axis, the bike becomes inherenly
UNstable - perhaps enough to start the first swerve in your
"oscillation".

The second, and I think most important issue is that you may not have
been properly braced for the inevitable deceleration from hitting the
speed bump. This will throw your body weight forward, and can result
in a nasty out-of-control bit of flailing around, followd by road
rash. This happened to me a few months ago when I didn't see a
fist-sized rock laying in the middle of the bike lane.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

My guess... there were probably two contributing factors to your
unfortunate accident.

One, when you go over a speed bump that has enough "bump", your front
wheel's contact patch (the part of the tire actually touching the
road) will be, for a moment, forward of your steering axis (a straight
line drawn through the center of your head tube to the ground).
Normally, the contact patch is behind this axis, which results in
"trail" - and this is what makes a bike inherently stable (kind of
like a shopping cart's rear pivoting wheels). But when the contact
patch is in front of the steering axis, the bike becomes inherenly
UNstable - perhaps enough to start the first swerve in your
"oscillation".

The second, and I think most important issue is that you may not have
been properly braced for the inevitable deceleration from hitting the
speed bump. This will throw your body weight forward, and can result
in a nasty out-of-control bit of flailing around, followd by road
rash. This happened to me a few months ago when I didn't see a
fist-sized rock laying in the middle of the bike lane.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

My guess... there were probably two contributing factors to your
unfortunate accident.

One, when you go over a speed bump that has enough "bump", your front
wheel's contact patch (the part of the tire actually touching the
road) will be, for a moment, forward of your steering axis (a straight
line drawn through the center of your head tube to the ground).
Normally, the contact patch is behind this axis, which results in
"trail" - and this is what makes a bike inherently stable (kind of
like a shopping cart's rear pivoting wheels). But when the contact
patch is in front of the steering axis, the bike becomes inherenly
UNstable - perhaps enough to start the first swerve in your
"oscillation".

The second, and I think most important issue is that you may not have
been properly braced for the inevitable deceleration from hitting the
speed bump. This will throw your body weight forward, and can result
in a nasty out-of-control bit of flailing around, followd by road
rash. This happened to me a few months ago when I didn't see a
fist-sized rock laying in the middle of the bike lane.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

On Mon, 25 Jul 2005 08:44:16 -0400, pam_in_sc <[email hidden]>

Quoted message said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Sorry to hear this, I hope you heal quickly.

Take care of yourself.

Life is Good!
Jeff

On Mon, 25 Jul 2005 08:44:16 -0400, pam_in_sc <[email hidden]>

Quoted message said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Sorry to hear this, I hope you heal quickly.

Take care of yourself.

Life is Good!
Jeff

On Mon, 25 Jul 2005 08:44:16 -0400, pam_in_sc <[email hidden]>

Quoted message said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Sorry to hear this, I hope you heal quickly.

Take care of yourself.

Life is Good!
Jeff

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Good luck. Hope you have a speedy recovery. Let your body tell you
when to start back. I rode again as soon as I was fairly certain that I
could do most things like shift and brake effectively. I'd banged up a
shoulder and cracked some ribs. By the time I got back on the bike, the
pain level from this was tolerable. Had a cast on my arm for six weeks
and started back riding the day after I got it off. That was more than
enough time for everything else to be in pretty good shape.

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Good luck. Hope you have a speedy recovery. Let your body tell you
when to start back. I rode again as soon as I was fairly certain that I
could do most things like shift and brake effectively. I'd banged up a
shoulder and cracked some ribs. By the time I got back on the bike, the
pain level from this was tolerable. Had a cast on my arm for six weeks
and started back riding the day after I got it off. That was more than
enough time for everything else to be in pretty good shape.

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

First question:
They had wooden ramps on the side where you approached the speed bump,
but not on the far side of the bump (the bikes going out and the bikes
coming in used different lanes). Going out it felt ok, so I didn't
worry about the speed bump much coming in. All I remember is that after
going over the bump my bike started to oscillate and I couldn't bring it
back into control. I've learned my lesson about going over speed bumps
too fast. But I'm curious more specifically what happened. I broke 13
spokes in my front wheel, but I assume that somehow happened after I
went down. The rim wasn't tacoed and the tire was still full of air.

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Good luck. Hope you have a speedy recovery. Let your body tell you
when to start back. I rode again as soon as I was fairly certain that I
could do most things like shift and brake effectively. I'd banged up a
shoulder and cracked some ribs. By the time I got back on the bike, the
pain level from this was tolerable. Had a cast on my arm for six weeks
and started back riding the day after I got it off. That was more than
enough time for everything else to be in pretty good shape.

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

.... snipped

Quoted message said:

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Pam,

I got surprised by a roller, went over the "handlebars" on my snowboard
in March and landed hard on my left shoulder. It hurt a bunch, and I
had what I thought was a bad bruise on top of my shoulder. Now, I know
it was a level 3 AC Joint Separation. I had a lot of swelling, but my
range of motion was still pretty good, so I didn't go to the doctor
initially - I was 19 (for 3 third time around), and there was more
snowboarding to be done. It was more than a couple of weeks later that
I noticed a lump (the end of my collar bone sticking up) in my shoulder
and pointed it out to my doctor when I went in for my annual check-up.
She had never seen one of those before and found the xrays to be quite
amusing - the separation was very evident.

For the first 3 weeks or so, some movements (like getting into/out of
pullover shirts, and pushing up from behind with that arm) hurt quite a
lot. Also, anything that pulled the arm out hurt initially. After a
month, the pain was mostly gone but I still got jolts out of some sudden
movements. It was about a month after the fall that I got on a bike,
but I probably could have done it sooner - I was just waiting for warm
weather. The only bike problem I had was when I tried my first
bunny-hop over a bad pavement joint. The quick pull-up made me wince.

As I understand it, surgery is possible, but done less often than not.
If I were a left-handed pitcher or quarterback, I guess it would be
called for. As a right-handed 58 year old desk jockey, surgery is not
really called for.

I wonder about competitive swimming though, did you ask about whether
this would affect your swimming ability in the long run?

- Dave

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

.... snipped

Quoted message said:

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Pam,

I got surprised by a roller, went over the "handlebars" on my snowboard
in March and landed hard on my left shoulder. It hurt a bunch, and I
had what I thought was a bad bruise on top of my shoulder. Now, I know
it was a level 3 AC Joint Separation. I had a lot of swelling, but my
range of motion was still pretty good, so I didn't go to the doctor
initially - I was 19 (for 3 third time around), and there was more
snowboarding to be done. It was more than a couple of weeks later that
I noticed a lump (the end of my collar bone sticking up) in my shoulder
and pointed it out to my doctor when I went in for my annual check-up.
She had never seen one of those before and found the xrays to be quite
amusing - the separation was very evident.

For the first 3 weeks or so, some movements (like getting into/out of
pullover shirts, and pushing up from behind with that arm) hurt quite a
lot. Also, anything that pulled the arm out hurt initially. After a
month, the pain was mostly gone but I still got jolts out of some sudden
movements. It was about a month after the fall that I got on a bike,
but I probably could have done it sooner - I was just waiting for warm
weather. The only bike problem I had was when I tried my first
bunny-hop over a bad pavement joint. The quick pull-up made me wince.

As I understand it, surgery is possible, but done less often than not.
If I were a left-handed pitcher or quarterback, I guess it would be
called for. As a right-handed 58 year old desk jockey, surgery is not
really called for.

I wonder about competitive swimming though, did you ask about whether
this would affect your swimming ability in the long run?

- Dave

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

.... snipped

Quoted message said:

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Pam,

I got surprised by a roller, went over the "handlebars" on my snowboard
in March and landed hard on my left shoulder. It hurt a bunch, and I
had what I thought was a bad bruise on top of my shoulder. Now, I know
it was a level 3 AC Joint Separation. I had a lot of swelling, but my
range of motion was still pretty good, so I didn't go to the doctor
initially - I was 19 (for 3 third time around), and there was more
snowboarding to be done. It was more than a couple of weeks later that
I noticed a lump (the end of my collar bone sticking up) in my shoulder
and pointed it out to my doctor when I went in for my annual check-up.
She had never seen one of those before and found the xrays to be quite
amusing - the separation was very evident.

For the first 3 weeks or so, some movements (like getting into/out of
pullover shirts, and pushing up from behind with that arm) hurt quite a
lot. Also, anything that pulled the arm out hurt initially. After a
month, the pain was mostly gone but I still got jolts out of some sudden
movements. It was about a month after the fall that I got on a bike,
but I probably could have done it sooner - I was just waiting for warm
weather. The only bike problem I had was when I tried my first
bunny-hop over a bad pavement joint. The quick pull-up made me wince.

As I understand it, surgery is possible, but done less often than not.
If I were a left-handed pitcher or quarterback, I guess it would be
called for. As a right-handed 58 year old desk jockey, surgery is not
really called for.

I wonder about competitive swimming though, did you ask about whether
this would affect your swimming ability in the long run?

- Dave

pam_in_sc said:

I wiped out in a triathlon Saturday. The whole long story is at:
http://deeplanguage.blogspot.com

.... snipped

Quoted message said:

Second question:
An x-ray showed some separation of the A-C joint of my shoulder, where
the collarbone meets the shoulder. Today, two days after the injury, it
hurts if I try to do any work with it, even lifting my arm, but not if
my arm is resting. I even ran slowly this morning with my arm in a
sling without pain. The doctor at the local urgent care center didn't
know very much and didn't tell me what level of A-C injury, but I would
guess 3 or less. I'm waiting for an appointment with an orthopedist,
but in the meantime does anyone have experience with such an injury and
how soon you went back to bicycling? It will take a while to get my
bike fixed but I have a yard-sale no-suspension mountain bike I could
ride. I'm sure it will be a while before I can get back to swimming so
I would like to get back to bicycling as soon as possible.

Pam

Pam,

I got surprised by a roller, went over the "handlebars" on my snowboard
in March and landed hard on my left shoulder. It hurt a bunch, and I
had what I thought was a bad bruise on top of my shoulder. Now, I know
it was a level 3 AC Joint Separation. I had a lot of swelling, but my
range of motion was still pretty good, so I didn't go to the doctor
initially - I was 19 (for 3 third time around), and there was more
snowboarding to be done. It was more than a couple of weeks later that
I noticed a lump (the end of my collar bone sticking up) in my shoulder
and pointed it out to my doctor when I went in for my annual check-up.
She had never seen one of those before and found the xrays to be quite
amusing - the separation was very evident.

For the first 3 weeks or so, some movements (like getting into/out of
pullover shirts, and pushing up from behind with that arm) hurt quite a
lot. Also, anything that pulled the arm out hurt initially. After a
month, the pain was mostly gone but I still got jolts out of some sudden
movements. It was about a month after the fall that I got on a bike,
but I probably could have done it sooner - I was just waiting for warm
weather. The only bike problem I had was when I tried my first
bunny-hop over a bad pavement joint. The quick pull-up made me wince.

As I understand it, surgery is possible, but done less often than not.
If I were a left-handed pitcher or quarterback, I guess it would be
called for. As a right-handed 58 year old desk jockey, surgery is not
really called for.

I wonder about competitive swimming though, did you ask about whether
this would affect your swimming ability in the long run?

- Dave

Mark Hickey said:

My guess... there were probably two contributing factors to your
unfortunate accident.

One, when you go over a speed bump that has enough "bump", your front
wheel's contact patch (the part of the tire actually touching the
road) will be, for a moment, forward of your steering axis (a straight
line drawn through the center of your head tube to the ground).
Normally, the contact patch is behind this axis, which results in
"trail" - and this is what makes a bike inherently stable (kind of
like a shopping cart's rear pivoting wheels). But when the contact
patch is in front of the steering axis, the bike becomes inherenly
UNstable - perhaps enough to start the first swerve in your
"oscillation".

The second, and I think most important issue is that you may not have
been properly braced for the inevitable deceleration from hitting the
speed bump. This will throw your body weight forward, and can result
in a nasty out-of-control bit of flailing around, followd by road
rash. This happened to me a few months ago when I didn't see a
fist-sized rock laying in the middle of the bike lane.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Thanks--this gives me ways to think about how to ride better.

Pam

Mark Hickey said:

My guess... there were probably two contributing factors to your
unfortunate accident.

One, when you go over a speed bump that has enough "bump", your front
wheel's contact patch (the part of the tire actually touching the
road) will be, for a moment, forward of your steering axis (a straight
line drawn through the center of your head tube to the ground).
Normally, the contact patch is behind this axis, which results in
"trail" - and this is what makes a bike inherently stable (kind of
like a shopping cart's rear pivoting wheels). But when the contact
patch is in front of the steering axis, the bike becomes inherenly
UNstable - perhaps enough to start the first swerve in your
"oscillation".

The second, and I think most important issue is that you may not have
been properly braced for the inevitable deceleration from hitting the
speed bump. This will throw your body weight forward, and can result
in a nasty out-of-control bit of flailing around, followd by road
rash. This happened to me a few months ago when I didn't see a
fist-sized rock laying in the middle of the bike lane.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Thanks--this gives me ways to think about how to ride better.

Pam

Mark Hickey said:

My guess... there were probably two contributing factors to your
unfortunate accident.

One, when you go over a speed bump that has enough "bump", your front
wheel's contact patch (the part of the tire actually touching the
road) will be, for a moment, forward of your steering axis (a straight
line drawn through the center of your head tube to the ground).
Normally, the contact patch is behind this axis, which results in
"trail" - and this is what makes a bike inherently stable (kind of
like a shopping cart's rear pivoting wheels). But when the contact
patch is in front of the steering axis, the bike becomes inherenly
UNstable - perhaps enough to start the first swerve in your
"oscillation".

The second, and I think most important issue is that you may not have
been properly braced for the inevitable deceleration from hitting the
speed bump. This will throw your body weight forward, and can result
in a nasty out-of-control bit of flailing around, followd by road
rash. This happened to me a few months ago when I didn't see a
fist-sized rock laying in the middle of the bike lane.

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $795 ti frame

Thanks--this gives me ways to think about how to ride better.

Pam