2002 RANS Rocket naturally veers left.

[Alpha Beta]

Hey Rocketeers and probably others bike owners with bike which have sever dishing of the rear wheel.

Have any of you notice a natural veering to the left.

I got off my bike and pushed it and I noticed it always veered to the left. This explains why it is
easier to bike one handed with the right hand on the steering rather than one hand with the left
hand on the steering.

I thinking it has something to do with dishing of the rear wheel which puts the the rear wheel off
the center-line. I noticed when after going through a puddle, the water trail on the dry pavement
showed me that the rear wheel was to the left of centre alignment.

With front fork trail, there is a tendency for the front wheel center to the direction of motion
which in this case is off to the left a little, thus the front wheel points consistently to the left
a little and thus it causes the bike to veer to the left.

No wonder I cannot ride with no hands on the steering.

Maybe recumbent manufactures should design their bikes with out dishing, because on a recumbent the
long change will not get bent as much.

 

[Mike Warner]

I have a 2002 Rocket.

> Have any of you notice a natural veering to the left.

NO, not at all.

> No wonder I cannot ride with no hands on the steering.

The bike has a 20-inch front wheel; extremely short wheelbase; and it has a long riser: this is the
reason you can't to ride it with no hands. Your veering problem is superfluous.

mc
--
Replace "****" with "warnerm" in my email addr

 

[Tom Sherman]

Mike Warner wrote:
>
> I have a 2002 Rocket.
>
> > Have any of you notice a natural veering to the left.
>
> NO, not at all.
>
> > No wonder I cannot ride with no hands on the steering.
>
> The bike has a 20-inch front wheel; extremely short wheelbase; and it has a long riser: this is
> the reason you can't to ride it with no hands. Your veering problem is superfluous.

I have not noticed any tendency for my RANS Rocket to prefer to go one direction over another unless
I am riding on a roadway with significant crown or other sloped surfaces.

The Rocket's wheelbase is longer than that of most SWB bikes designed prior to the mid 1990's - the
most notable exception is the Lightning P-38. [1] Therefore, it should not be classified as an
extremely short wheelbase design (particularly 2001+ models).

As I have mentioned before, several riders are capable of riding a RANS Rocket no-handed - I
strongly suspect most unicyclists could do so. [2]

[1] A short wheelbase is necessary if the goal is to have both a low BB relative to the seat and
minimal foot/wheel interference while turning. Many recent SWB designs (e.g. Bacchetta) have
followed the example of Lightning and gone with a shorter boom and higher BB to improve frame
stiffness (relative to pedaling induced forces), weight distribution and to reduce frontal area.

[2] The rider who I mentioned previously who would ride several miles no handed on a square-tube
(first generation) Rocket was also a regular unicyclist.

Tom Sherman - Various HPV's Quad Cities USA (Illinois side)

 

[Mikael Seierup]

"Alpha Beta" skrev...
> Hey Rocketeers and probably others bike owners with bike which have sever dishing of the
> rear wheel.
>
> Have any of you notice a natural veering to the left.
>
> I got off my bike and pushed it and I noticed it always veered to the left. This explains why it
> is easier to bike one handed with the right hand on the steering rather than one hand with the
> left hand on the steering.

I think theres a problem with the coriolis-setting. Your bike must have been set up for a lower
lattitude from the factory, so it overcompensates. You need to locate a little screw close to the
fork. Think its under the frame. It has a little globesymbol next to it. Then turn it a few
milimeters clockwise. Test bike to see if it tracks straight and adjust again if it doesn't.

Hope this helps Mikael

 

[Tom Sherman]

Mikael Seierup wrote:
>
> I think theres a problem with the coriolis-setting. Your bike must have been set up for a lower
> lattitude from the factory, so it overcompensates. You need to locate a little screw close to the
> fork. Think its under the frame. It has a little globesymbol next to it. Then turn it a few
> milimeters clockwise. Test bike to see if it tracks straight and adjust again if it doesn't.
>
> Hope this helps Mikael

I believe the solution would be to get a new set of wheels - these should cure the problem. <
http://www.sheldonbrown.com/symspoke.html >

Tom Sherman - Various HPV's Quad Cities USA (Illinois side)

 

[John Foltz]

"Mikael Seierup" <[email protected]> wrote in message
news:<[email protected]>...
> "Alpha Beta" skrev...
> >
> > I got off my bike and pushed it and I noticed it always veered to the left.

> I think theres a problem with the coriolis-setting. Your bike must have been set up for a lower
> lattitude from the factory, so it overcompensates. You need to locate a little screw close to the
> fork. Think its under the frame. It has a little globesymbol next to it. Then turn it a few
> milimeters clockwise. Test bike to see if it tracks straight and adjust again if it doesn't.
>
Hmm, I thought that the adjustment is now put in the headset. I know, maybe the headset has been
installed backwards! Here are some other possibilities, listed in order of their probability.

* Magnetic properties of the spokes on the front wheel do not align with the earth's magnetic field.
Obviously, if your front wheel is pushed or pulled with relation to the earth's geomagnetic north
pole, it will initiate a turn.

* Gravity is stronger on the right side. I know this sounds counter-intuitive, but having more
gravity on the right makes the bike lean right, which initiates a left turn.

* You are riding/walking too near the edge of the road, or maybe you are on a sidewalk instead of
being in the road where you belong. The bike realizes this, and is trying to correct your improper
lane usage.

* The wheels could be improperly dished, or set crooked in the dropouts.

* Or, finally, the cables coming off the right side of the riser are pushing the steering slightly
to the left.
--

 

[John Riley]

Jeez, now even the _bikes_ have political opinions ;-)

I had a bike that would veer when I pushed it because of the springiness of the cable guides.

JR

 

[B. Sanders]

"Alpha Beta" <[email protected]> wrote in message
news:[email protected]...
> Hey Rocketeers and probably others bike owners with bike which have sever dishing of the
> rear wheel.
>
> Have any of you notice a natural veering to the left.

Check the front brake cable. Is it applying slight pull to the steerer? That was the problem on my
old Ryan Vanguard. I replaced the brake cable, and fixed the veering problem.

-Barry

 

[Lennert Thunber]

If the rear wheel is properly dished it will be on the centerline of the bike. Have you checked the
dish? Other causes of the veering could be an out-of-alignment frame or an assymetrical fork.

Len

"Alpha Beta" <[email protected]> wrote in message
news:[email protected]...
> Hey Rocketeers and probably others bike owners with bike which have sever dishing of the
> rear wheel.
>
> Have any of you notice a natural veering to the left.
>
> I got off my bike and pushed it and I noticed it always veered to the
left.
> This explains why it is easier to bike one handed with the right hand on
the
> steering rather than one hand with the left hand on the steering.
>
> I thinking it has something to do with dishing of the rear wheel which
puts
> the the rear wheel off the center-line. I noticed when after going through
a
> puddle, the water trail on the dry pavement showed me that the rear wheel was to the left of
> centre alignment.
>
> With front fork trail, there is a tendency for the front wheel center to
the
> direction of motion which in this case is off to the left a little, thus
the
> front wheel points consistently to the left a little and thus it causes
the
> bike to veer to the left.
>
> No wonder I cannot ride with no hands on the steering.
>
> Maybe recumbent manufactures should design their bikes with out dishing, because on a recumbent
> the long change will not get bent as much.