Why does my new bike want to turn left by itself?

Hello,

Maybe someone can offer some explainations on why my new '05 Bianchi
Vigorelli wants to turn left by itself. The LBS swears the frame is
straight, but riding no-handed (I know, I know...) and exerting some effort
on the pedals REQUIRES the inside of my left thigh to be firmly planted
against the nose of the seat to remain riding straight ahead. Shifting
positions on the seat does not rectify the problem. This bothers me on a
brand new bike.

Only thing I can think of would be the cables and housings looping to the
handlebars might be putting unequal pressure one way or the other.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go figure.

Thanks for any help,
Mat Barringer
too small now for too large old bike

Mat & Mary Barringer writes:

Maybe someone can offer some explanations on why my new '05 Bianchi
Vigorelli wants to turn left by itself. The LBS swears the frame is
straight, but riding no-handed (I know, I know...) and exerting some
effort on the pedals REQUIRES the inside of my left thigh to be
firmly planted against the nose of the seat to remain riding
straight ahead. Shifting positions on the seat does not rectify the
problem. This bothers me on a brand new bike.

Only thing I can think of would be the cables and housings looping
to the handlebars might be putting unequal pressure one way or the
other.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go
figure.

The fork is crooked and probably got so in shipping from the factory.

http://www.sheldonbrown.com/brandt/pull-side.html

Jobst Brandt

Mat & Mary Barringer wrote:
Hello,

Maybe someone can offer some explainations on why my new '05 Bianchi
Vigorelli wants to turn left by itself. The LBS swears the frame is
straight, but riding no-handed (I know, I know...) and exerting some effort
on the pedals REQUIRES the inside of my left thigh to be firmly planted
against the nose of the seat to remain riding straight ahead. Shifting
positions on the seat does not rectify the problem. This bothers me on a
brand new bike.

Lots of things can cause this - misaligned frames, misaligned forks,
incorrectly dished wheels. Frames and wheels it's easy to check
yourself. Fork alignment gauges/jigs are a little harder to substitute
at home, and the fork will need to be removed however you do it. When
I've needed to check the alignment on a fork without any tools, I've
had pretty good results by getting fixing it to a big piece of carboard
and setting down lines that correspond to the inside faces of the
dropouts and the outside and centerline of the steerer. This doesn't
check fore/aft blade alignment, but there are probably some other
tool-free ways of doing that as well. Typical OEM carbon forks such as
yours are perfectly liable to come out of the factory poorly aligned.

Tracking problems are the kind of thing a bike shop just doesn't want
to deal with, especially on a 2 year old bike. (By "new" you mean you
just bought this, right?) An average shop just wants this to go out the
door and never come back, and that's not a cynical exaggeration. I
doubt the Ksyriums are going to be undished and causing a tracking
problem (worth checking though), so you are looking at a situation
where you have to force them to take it back.

Only thing I can think of would be the cables and housings looping to the
handlebars might be putting unequal pressure one way or the other.

Incorrectly set up housings can indeed affect tracking, but it should
be obvious if this is going on. There should be a non-zero amount of
slack in the cables when the bars are turned to either extreme.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go figure.

Thanks for any help,
Mat Barringer
too small now for too large old bike

On Wed, 20 Sep 2006 21:15:40 -0500, "Mat & Mary Barringer"
wrote:

Hello,

Maybe someone can offer some explainations on why my new '05 Bianchi
Vigorelli wants to turn left by itself. The LBS swears the frame is
straight, but riding no-handed (I know, I know...) and exerting some effort
on the pedals REQUIRES the inside of my left thigh to be firmly planted
against the nose of the seat to remain riding straight ahead. Shifting
positions on the seat does not rectify the problem. This bothers me on a
brand new bike.

Only thing I can think of would be the cables and housings looping to the
handlebars might be putting unequal pressure one way or the other.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go figure.

Thanks for any help,
Mat Barringer
too small now for too large old bike

Dear Mat,

Bianchi Vigorelli . . .

Turns left . . .

Rome, Italy (AP)

"Police in Rome are appealing to the public for leads to the
whereabouts of Bianchi "Vigo" Vigorelli, the notorious "Red Plumber"
of Italy, whose rise to the head of the left-wing Italian plumbing
union was cut short when his Mafia connections were accidentally
revealed during the 2006 Giro."

"Vigorelli's unions sponsored a Giro team mounted on bicycles made
literally of plumbing pipe, claiming that the extra weight gave them a
crucial advantage on the downhills."

"The plumbing-union team's unlikely success was explained when a mass
of splintered carbon-fiber frames was discovered under the Giro
podium, all bearing the marks of savage beatings with lead pipes."

"The grisly bicycle graveyard was discovered in a freak accident after
Vigorelli himself leapt onto one of his team's ungainly steeds and
attempted a no-hands victory ride near the podium, with both hands
raised in V-for-victory signs."

"As soon as Vigorelli let go of the handlebars, his bicycle swerved
violently to the left and smashed into the podium, revealing what had
happened to his competitors' bicycles."

"As enthusiasts debated whether the carbon frame were truly
compromised, Vigorelli escaped in the confusion, fleeing the scene on
what onlookers described as a Fury RoadMaster, a somewhat heavyset
bicycle sold by a chain of non-union U.S. stores. A police artist's
sketch shows the getaway vehicle turning to the right."

"Vigorelli is considered armed, but not particularly dangerous. 'He's
a bicyclist,' said one Roman detective assigned to the case, shrugging
his shoulders. 'Who takes a grown man on a bicycle seriously?'"

Cheers,

Carl Fogel

Mat & Mary Barringer wrote:
Hello,

Maybe someone can offer some explainations on why my new '05 Bianchi
Vigorelli wants to turn left by itself. The LBS swears the frame is
straight, but riding no-handed (I know, I know...) and exerting some effort
on the pedals REQUIRES the inside of my left thigh to be firmly planted
against the nose of the seat to remain riding straight ahead. Shifting
positions on the seat does not rectify the problem. This bothers me on a
brand new bike.

Only thing I can think of would be the cables and housings looping to the
handlebars might be putting unequal pressure one way or the other.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go figure.

Thanks for any help,
Mat Barringer
too small now for too large old bike

Could be the headset is a tad too tight. Or maybe the wheel's quick
release is too tight.

On Wed, 20 Sep 2006 21:15:40 -0500, Mat & Mary Barringer wrote:

Only thing I can think of would be the cables and housings looping to the
handlebars might be putting unequal pressure one way or the other.

That would be my bet.

--

David L. Johnson

__o | A mathematician is a machine for turning coffee into theorems.
_`\(,_ | -- Paul Erdos
(_)/ (_) |

Mat & Mary Barringer wrote:
Hello,

Maybe someone can offer some explainations on why my new '05 Bianchi
Vigorelli wants to turn left by itself. The LBS swears the frame is
straight, but riding no-handed (I know, I know...) and exerting some effort
on the pedals REQUIRES the inside of my left thigh to be firmly planted
against the nose of the seat to remain riding straight ahead. Shifting
positions on the seat does not rectify the problem. This bothers me on a
brand new bike.

Only thing I can think of would be the cables and housings looping to the
handlebars might be putting unequal pressure one way or the other.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go figure.

Thanks for any help,
Mat Barringer
too small now for too large old bike


I've experienced this problem twice on roadbikes I've purchased new.
Each time, the bike wound up developing an off-center rear wheel (a
dishing error) after accumulating a couple-few thousand miles on wheels
that were poorly tensioned.

At the point where the ride quality was severely impacted, the
off-center positioning of the rear wheel could be seen by carefully
looking at how the wheel lined up between the chain stays. When
off-center, the wheel is closer to one chain stay than the other chain
stay. It's made easier to see by the fact that the apparent offset
between the stays is actually double the dishing error, as the wheel is
at once spaced away from one stay and toward the other stay, creating a
offcenter distance of, say, 1/4" when the actual dishing error is only
1/8".

In both cases the problem was corrected by redishing the rear wheel to
properly center it in the frame. -BG

Mat & Mary Barringer wrote:
Hello,

Maybe someone can offer some explainations on why my new '05 Bianchi
Vigorelli wants to turn left by itself. The LBS swears the frame is
straight, but riding no-handed (I know, I know...) and exerting some effort
on the pedals REQUIRES the inside of my left thigh to be firmly planted
against the nose of the seat to remain riding straight ahead. Shifting
positions on the seat does not rectify the problem. This bothers me on a
brand new bike.

Only thing I can think of would be the cables and housings looping to the
handlebars might be putting unequal pressure one way or the other.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go figure.

Thanks for any help,
Mat Barringer
too small now for too large old bike

Is the same true for somebody else riding the bike?? I'm guessing how
you are seated on the thing, weight distribution..Have somebody you
trust ride it.

Mat & Mary Barringer wrote:
Hello,

Maybe someone can offer some explainations on why my new '05 Bianchi
Vigorelli wants to turn left by itself. The LBS swears the frame is
straight, but riding no-handed (I know, I know...) and exerting some
effort on the pedals REQUIRES the inside of my left thigh to be
firmly planted against the nose of the seat to remain riding straight
ahead. Shifting positions on the seat does not rectify the problem.
This bothers me on a brand new bike.

Only thing I can think of would be the cables and housings looping to
the handlebars might be putting unequal pressure one way or the other.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go
figure.

Thanks for any help,
Mat Barringer
too small now for too large old bike

Nobody mentioned this, but take into account any road crown in your tests.
--
Phil Lee, Squid

Phil Lee writes:

Maybe someone can offer some explanation on why my new '05
Bianchi Vigorelli wants to turn left by itself. The LBS swears the
frame is straight, but riding no-handed (I know, I know...) and
exerting some effort on the pedals REQUIRES the inside of my left
thigh to be firmly planted against the nose of the seat to remain
riding straight ahead. Shifting positions on the seat does not
rectify the problem. This bothers me on a brand new bike.

As it should. Your fork is bent. This should be visible on the road
when you follow another rider on this bicycle while he rides it
no-hands. The wheels are not in the same plane. If this is not a
metal fork, then you need a new one, otherwise it can be straightened.

Only thing I can think of would be the cables and housings looping
to the handlebars might be putting unequal pressure one way or the
other.

My 24 year old Schwinn Voyageur 11.8 tracks straight and true. Go
figure.

Nobody mentioned this, but take into account any road crown in your
tests.

The reason no one mentioned it is that it has no perceptible effect on
straight ahead riding. You need to watch track racers ride no-hands
at low speed on a banked track to see that, or ride no-hands down your
own residential street.

Jobst Brandt