My Experiment...

[Mark Thompson]

> Use a thin headset spanner to hold the threaded race (immediately
> below the locknut) and loosen the locknut. Tighten the threaded race
> until the steering is solid then tighten the locknut down onto it
> without backing off the threaded race.

Failure. The threaded race couldn't be tightened at all by hand, and it
didn't have spanner-grabby bits on to be tightened with a spanner.

I then set about buggering up the (nice) Trek. The crappy headset spanner
(or possibly the crappy headset) wasn't a good fit, and I was unable to
tighten the threaded race sufficiently to prevent all steering. At least
I'll learn how to adjust a headset properly now

 

[Tim Forcer]

On Fri, 23 Feb 2007 19:40 Pete Biggs wrote:
>
> Another link:
>
> http://www.sheldonbrown.com/brandt/descending.html :
>
> "What is not apparent, is that two wheeled vehicles can be controlled ONLY
> by countersteer, there is no other way. Unlike a car, a bicycle cannot be
> diverted from a straight path by steering the wheel to one side ...

When a stunt driver puts a car up on two wheels, ISTR the front wheels
countersteer visibly. I suspect this is because they are at a hideous
angle in two wheel mode, making the geometry VERY peculiar in terms of
castor and so on. With the significant gearing between steering wheel
and roadwheel steering axis, the former's movement should be far more
obvious than that seen on a bike's ungeared steering?

--
Tim Forcer [email protected]
The University of Southampton, UK

The University is not responsible for my opinions

 

[Al C-F]

dkahn400 wrote:

>
> Use a thin headset spanner to hold the threaded race (immediately
> below the locknut) and loosen the locknut. Tighten the threaded race
> until the steering is solid then tighten the locknut down onto it
> without backing off the threaded race.

Then buy a new headset to replace the one you've just buggered up.

 

[Ben C]

On 2007-03-02, [email protected] <[email protected]> wrote:
> On Mar 2, 5:24 pm, Ben C <[email protected]> wrote:
[...]
>>
>> It's not a contradiction. If you're sitting in zero-gravity, you can
>> touch your toes. Your COM moves relative to your toes, but not relative
>> to the NRF.
>
> Yes, the toes can move relative to the NRF. Are you claiming that the
> contact patch does? If so, how, other than by steering?

No. The contact patch does not have to move for a rider to lean a bike
over to one side.

>> A movement like that, not requiring any lateral forces from the NRF,
>
> What sort of (lateral) movement is it that requires no lateral force?

I said lateral forces from the NRF, or in other words external lateral
forces, are not required. A rider in zero-G can move his tyres to one
side relative to his own centre of mass by applying a force.

>> > To put the shoe on the other foot, since you are not prepared to try
>> > the trivial experiments I have suggested (which certainly would show
>> > that the possibility to "just shift your centre of mass sideways" is
>> > extremely limited), can you suggest any experiment which would
>> > actually demonstrate the existence of such an ability at a level which
>> > might make a perceptible difference in bicycle riding?
>>
>> As I said earlier, leaning into a corner does not require clown ability.
>> Clowns enter the discussion only to illuminate the descriptions of why
>> it is possible to lean over without needing psychokinesis. We use the
>> same physics as the clowns, but not the same skill. They use this effect
>> to balance on things, I'm only suggesting that cyclists may use it to
>> initiate turns.
>
> To put the shoe on the other foot, since you are not prepared to try
> the trivial experiments I have suggested (which certainly would show
> that the possibility to "just shift your centre of mass sideways" is
> extremely limited), can you suggest any experiment which would
> actually demonstrate the existence of such an ability at a level which
> might make a perceptible difference in bicycle riding?

I should have made it clearer: I am not suggesting that this mechanism
of balance is used by any normal bike rider and so I don't think this
experiment is necessary.

That it might be used to initiate turns is possible. I'm not sure what
would be a good experiment to test for that.

 

[dkahn400]

On Mar 2, 2:54 pm, Al C-F
<[email protected]> wrote:

> Then buy a new headset to replace the one you've just buggered
> up.

>From Mark's reply it looks as though he may have to.

Seriously though, it shouldn't do any damage as long as it remains
locked.

--
Dave...

 

[Rob Morley]

In article <[email protected]>,
dkahn400
[email protected] says...
> On Mar 2, 2:54 pm, Al C-F
> <[email protected]> wrote:
>
> > Then buy a new headset to replace the one you've just buggered
> > up.
>
> >From Mark's reply it looks as though he may have to.
>
> Seriously though, it shouldn't do any damage as long as it remains
> locked.
>
You'd have to overtighten it considerably to lock it solid - if the
bearing faces are harder than the balls (unlikely) then the balls might
break, otherwise they're likely to leave dents in the bearing faces.