Tracking problem

Badger_South wrote:
|| On Thu, 4 Nov 2004 18:50:19 -0500, "Roger Zoul"
|| wrote:
||
||||| I picked 90" to 2 hours as the point at which some ppl start
||||| eating
||||| and drinking during the ride. You say 3 hours, I don't disagree.
|||
||| Well, it's your opinion. I'm of the opinion that if I need to
||| stretch or eat or whatever, I'll get off the bike. I'm not a pro so
||| there's no need to do other things while riding. I don't need the
||| hassle of getting hurt needlessly. Income to protect,
||| responsibilities, etc. YMMV.
||
|| Not trying to be argumentative, but I don't expect to fall off the
|| bike at speed, but I still ride and I go down hills and reach 35mph.
|| That's gotta
|| be more dangerous than riding no hands to get something out of your
|| jersey back pocket, such as a dispo. camera.

Well, I don't expect to fall at speed either....but it seems when you ride
no-handed, you increase your changes of falling as you're usually shifting
around and stuff.

||
||| BTW, I usually get off the bike at about 20 miles, so your 1.5
||| hours is about right for me
||
|| My experience may be different, b/c I don't equate riding with no
|| hands as dangerous at all, given you don't pick the wrong time or
|| part of the road
|| to do it sparingly. I'm not advocating riding that way to impress
|| the babes or anything.



||
|| It isnt' even so much that, as it's irritating to -not- be able to
|| ride no hands, even coasting, and take off your sunglasses and put
|| on your spares.


||
|| So you telling me you're just over-cautious, or that never having
|| done that you have none of the skills. You'll never get on a
|| unicycle, then? Just askin', not trying to be a butt.

Actually, I used to do it all the time when I was a kid...but for some
reason that skill has not returned. Not that I've been trying hard to
develop it, though.

||
|| I've never even come close to getting hurt or even a hint of it, and
|| I used to do it a lot with my paper route. I'd fold the papers while
|| riding and throw them up on the porch.

Same here.

||
|| As I said, it's part of bike handling, imo. Sure, elect not to do it
|| much, but don't totally avoid having the skill set.
||
|| -B
|| Several of my cycling books talk about it, and one mentions it's
|| necessary skill, but not sure of their context. I'll look it up if
|| you like.

Naw...just curious.....so how do you work up that skill -- without getting
killed?

On Thu, 4 Nov 2004 20:12:02 -0500, "Roger Zoul"
wrote:

Several of my cycling books talk about it, and one mentions it's
|| necessary skill, but not sure of their context. I'll look it up if
|| you like.

Naw...just curious.....so how do you work up that skill -- without getting
killed?

60% of it is the bike. Actually I was reading a web-based biking forum, I
think, and one guy was talking about how amazingly well his new bike was
'tracking'. Then talked about holding it by the back of the saddle and just
easing it along, and it rode dead level straight on the carpet of the bike
store, and without even trying to 'balance' it.

When I got on my brother's bike, I rode immediately without hands, but
could tell the skill had degraded too. On mine there seems to be some
threshold 'value' that's not giving me the right kinesiological cues to let
go and feel safe. In addition, since mine has the top tube that slopes, you
can't grasp it betwen the knees, which helps you stready it until the sense
of balance returns.

I was thinking of having a short piece of strapping around one H/B, so I
could completely sit up, but still lightly restrain them from flopping to
the left.

Remind me of what bike you ride? I'd like to look at a comparable pic to
see the top tube geometry.

-B

Badger South (who?) writes:

I finally found the root cause of my problem with the bike not
tracking properly. Trek hybrid, no shocks, tires are 700x35c just a
touch of crosshatching treat, almost looks bald.

Tread pattern does not make riding no-hands easier. This has nothing
to do with tracking. In fact, knobs on some MTB tires make no-hands
riding difficult on an otherwise stable bicycle.

The third lbs guy to look at it spun the tire and said 'you have a
shimmy in the tire. The tire may have been put on incorrectly and
the bead of the tire might not have been in the rim straight'.

Tires don't have shimmies, frames do. If your tire has a bulge and
has so many miles on it that it is bald, then you probably have a tire
casing rupture, a larger cord failure. These can blow out.

It's a small and hardly noticeable section with the tire is off true
for about 8 inches, and it's definitely the rubber tire portion, but
you have to spin it a time or two if you're not used to looking at
tires.

He said he spotted it when spinning my front wheel and checking the
brakes. This guy was really nice, b/c he gave me a quick tune up
while putting on my SPDs. If he'd looked like Halle Berry,
I'da...well, you know. ;-D

I can't tell from here what sort of terms he used to describe the
fault but it doesn't sound right in your re-telling of it.

I noticed the lack of tracking when holding the back of the saddle
and trying to roll the bike forwards. Despite my trying time after
time to do this and keep the tiny bit of correction going with
tilting it, this bike will -not- track straight; thus I can not ride
it without hands, and you -need- to be able to ride no hands when
you're going over 90 minutes to two hours, IMO. If this doesn't fix
it, maybe the headset needs examined or something.

From what you say, it sounds more like too tight a head bearing. Does
the front wheel swing freely from side-to-side when the bicycle is
lifted and held just forward of the tilt angle at which it responds to
rearward tilt? That is, just ahead of the neutral tilt? If that
point is ill defined, you already have the answer. It's too tight.

So I'll have 'em look at this, and probably change the tire.

Get to the point where you can do this yourself. This is simple
stuff. It's when it requires new parts or special tools that you
should go to the LBS.

Jobst Brandt

Badger South (who?) writes:

I was thinking of having a short piece of strapping around one H/B,
so I could completely sit up, but still lightly restrain them from
flopping to the left.

Hold it, you didn't say that before. I took it that the response was
unstable. If it prefers to veer to the left then the fork ends are
most likely off center to the right. It is either the fork or the
frame with a leaning headtube that causes the same effect.

Remind me of what bike you ride? I'd like to look at a comparable
pic to see the top tube geometry.

You can't see anything from the shape or angle of a top tube,
especially with one that normally slopes down forward or rearward.

Jobst Brandt

On Fri, 05 Nov 2004 02:40:02 GMT, wrote:


I can't tell from here what sort of terms he used to describe the
fault but it doesn't sound right in your re-telling of it.

It's not a bulge. If you look at the line of contact around the center apex
of the tire, in a short section this veers to the left, (you are facing the
bike viewing edge on), then returns to center. The rest of the contact line
is centered perfectly.

I noticed the lack of tracking when holding the back of the saddle
and trying to roll the bike forwards. Despite my trying time after
time to do this and keep the tiny bit of correction going with
tilting it, this bike will -not- track straight; thus I can not ride
it without hands, and you -need- to be able to ride no hands when
you're going over 90 minutes to two hours, IMO. If this doesn't fix
it, maybe the headset needs examined or something.

From what you say, it sounds more like too tight a head bearing. Does
the front wheel swing freely from side-to-side when the bicycle is
lifted and held just forward of the tilt angle at which it responds to
rearward tilt? That is, just ahead of the neutral tilt? If that
point is ill defined, you already have the answer. It's too tight.

It flops to the left.

So I'll have 'em look at this, and probably change the tire.

Get to the point where you can do this yourself. This is simple
stuff. It's when it requires new parts or special tools that you
should go to the LBS.

Hip injury.

-B
Thx.

Badger_South wrote:
|| On Thu, 4 Nov 2004 20:12:02 -0500, "Roger Zoul"
|| wrote:
||
||| Several of my cycling books talk about it, and one mentions it's
||||| necessary skill, but not sure of their context. I'll look it up if
||||| you like.
|||
||| Naw...just curious.....so how do you work up that skill -- without
||| getting killed?
||
|| 60% of it is the bike. Actually I was reading a web-based biking
|| forum, I think, and one guy was talking about how amazingly well his
|| new bike was 'tracking'. Then talked about holding it by the back of
|| the saddle and just easing it along, and it rode dead level straight
|| on the carpet of the bike store, and without even trying to
|| 'balance' it.
||
|| When I got on my brother's bike, I rode immediately without hands,
|| but could tell the skill had degraded too. On mine there seems to be
|| some threshold 'value' that's not giving me the right kinesiological
|| cues to let go and feel safe. In addition, since mine has the top
|| tube that slopes, you can't grasp it betwen the knees, which helps
|| you stready it until the sense of balance returns.
||
|| I was thinking of having a short piece of strapping around one H/B,
|| so I could completely sit up, but still lightly restrain them from
|| flopping to the left.
||
|| Remind me of what bike you ride? I'd like to look at a comparable
|| pic to see the top tube geometry.

Specialized Sequoia Expert, 2003. Sloping top tube.

http://tinyurl.com/65zo5

On Fri, 05 Nov 2004 03:08:03 GMT, wrote:

Badger South (who?) writes:

I was thinking of having a short piece of strapping around one H/B,
so I could completely sit up, but still lightly restrain them from
flopping to the left.

Hold it, you didn't say that before. I took it that the response was
unstable. If it prefers to veer to the left then the fork ends are
most likely off center to the right. It is either the fork or the
frame with a leaning headtube that causes the same effect.

Remind me of what bike you ride? I'd like to look at a comparable
pic to see the top tube geometry.

You can't see anything from the shape or angle of a top tube,
especially with one that normally slopes down forward or rearward.

Jobst Brandt


If I roll the bike in the house holding the back of the seat, I can't push
it more than a couple inches before it tries to completely flop to one
side, be it right or left. Even with gentle steering by leaning I can
'correct' for a few inches and it flops to the other side. I tried for
quite a while to get it to track straight, and it would not.

So this seems to point to it being the looseness or tightness of the head
tube. One person told me it may be the head tube is too loose, and that
tightening it would prevent such easy flop to the side.

On the angle of the top tube, I was wonderng how important it was to be
able to lightly trap the top tube between the thighs when first starting to
ride no hands. The slope from front to seat post was such that I couldn't
touch it with my knees, side of the leg, nothing. A top tube that's level
from h/b to seat tube, I can grasp lightly between the thighs, and this
helps. Later, iirc, you don't need this.

-B

On Thu, 4 Nov 2004 22:26:40 -0500, "Roger Zoul"
wrote:

Badger_South wrote:
|| On Thu, 4 Nov 2004 20:12:02 -0500, "Roger Zoul"
|| wrote:
||
||
|| Remind me of what bike you ride? I'd like to look at a comparable
|| pic to see the top tube geometry.

Specialized Sequoia Expert, 2003. Sloping top tube.

http://tinyurl.com/65zo5

Nice.

When you gently push the bike forward by holding under the back edge of the
seat, palm up, does it track (roll forward) straight without too much
effort? If it does, I believe that's a good sign. If it doesn't, gee it may
be user error.

My brother's bike when pushed forwards like this goes straight (he's got
the same model, but two grades lower), and as you walk faster, it continues
to do this. Mine a few inches, feet at the most, the h/b flop to one side
or the other. Even if you gently angle or rock the bike ever so slightly to
the opposing side to gentle it into staying straight, as soon as you do
this it flops completely to -that- side. Don't even try to walk briskly
with it. Given that I can walk his and not mine makes me think it's not me.
;-)

-B

Badger South who? writes:

I can't tell from here what sort of terms he used to describe the
fault but it doesn't sound right in your re-telling of it.

It's not a bulge. If you look at the line of contact around the
center apex of the tire, in a short section this veers to the left,
(you are facing the bike viewing edge on), then returns to
center. The rest of the contact line is centered perfectly.

I noticed the lack of tracking when holding the back of the saddle
and trying to roll the bike forwards. Despite my trying time after
time to do this and keep the tiny bit of correction going with
tilting it, this bike will -not- track straight; thus I can not
ride it without hands, and you -need- to be able to ride no hands
when you're going over 90 minutes to two hours, IMO. If this
doesn't fix it, maybe the headset needs examined or something.

From what you say, it sounds more like too tight a head bearing.
Does the front wheel swing freely from side-to-side when the
bicycle is lifted and held just forward of the tilt angle at which
it responds to rearward tilt? That is, just ahead of the neutral
tilt? If that point is ill defined, you already have the answer.
It's too tight.

It flops to the left.

Then you aren't performing the test as described. Tilt the bicycle
forward until the wheel does NOT flop to one side anymore and then
lean the frame gently from side to side and see if the steering
follows smoothly. This is the simpler in situ test that can also be
made by removing the front wheel and bars to see how freely the fork
rotates in the head bearing using thumb and forefinger for rotation.

So I'll have 'em look at this, and probably change the tire.

Get to the point where you can do this yourself. This is simple
stuff. It's when it requires new parts or special tools that you
should go to the LBS.

Hip injury.

The LBS has no influence there. I hope you went elsewhere for that.

Jobst Brandt

Badger South (who?) writes:

I was thinking of having a short piece of strapping around one
H/B, so I could completely sit up, but still lightly restrain them
from flopping to the left.

Hold it, you didn't say that before. I took it that the response
was unstable. If it prefers to veer to the left then the fork ends
are most likely off center to the right. It is either the fork or
the frame with a leaning headtube that causes the same effect.

Remind me of what bike you ride? I'd like to look at a comparable
pic to see the top tube geometry.

You can't see anything from the shape or angle of a top tube,
especially with one that normally slopes down forward or rearward.

If I roll the bike in the house holding the back of the seat, I
can't push it more than a couple inches before it tries to
completely flop to one side, be it right or left. Even with gentle
steering by leaning I can 'correct' for a few inches and it flops to
the other side. I tried for quite a while to get it to track
straight, and it would not.

If you do this at less than walking speed, I would expect any bicycle
to do that. How does it compare with other people's bicycles? Have
you ever walked with a bicycle held by the saddle only in this manner.
It takes a bit of manual dexterity. From what you say here,
understanding the circumstances of your bicycle instability is not
easy and for this reason, I suspect you are not adept at this sort of
thing. Can you walk with your hip repair and test the straight ahead
stability of the hand guided bicycle?

On the other hand, if you could precisely describe the symptoms, you
would probably not ask, because the solution would be contained in
your description.

So this seems to point to it being the looseness or tightness of the
head tube. One person told me it may be the head tube is too loose,
and that tightening it would prevent such easy flop to the side.

Not at all. The test must be made, but walking a bicycle with hand on
the saddle does not a good test make other than that the head bearings
are not too tight. That the bicycle has a bias only comes out when
riding no-hands (without wind) down the road. Road crown does not
affect this.

On the angle of the top tube, I was wondering how important it was
to be able to lightly trap the top tube between the thighs when
first starting to ride no hands. The slope from front to seat post
was such that I couldn't touch it with my knees, side of the leg,
nothing. A top tube that's level from h/b to seat tube, I can grasp
lightly between the thighs, and this helps. Later, iirc, you don't
need this.

That is not necessary but it is useful when coasting downhill no-hands
because most bicycles for tall people tend to shimmy and laying the
leg against the top tube is the way it is most easily controlled.

Jobst Brandt