Re: Countersteering 101: Shut the **** Up and Listen

[Dan Connelly]

Howard Kveck wrote:
> In article <[email protected]>,
> Dan Connelly <d_j_c_o_n_n_e_l@y_a_h_o_o_._c_o_m> wrote:
>> Consider a 250 meter track, with 150
>> meters in corners, and 100 meters in straights. If the corners are
>> semicircular, they have a radius of R = (150 meters / 2 pi). If the
>> bike center-of-mass (COM) is going v = 60 km/hr = 16.7 m/sec, it is
>> experiencing a centrifugal acceleration relative to gravity of (v^2/R g)
>> = 1.19 (I'll define this as alpha).

> Thanks for the calculations, Dan.
>

Thanks...

Actually, the most interesting aspect to me is that the cyclist is
pulling sqrt(1 + alpha^2) = 1.55 g's in the corner. For me, that's an
extra 70lb or so on top of 125. Ouch.

Dan

 

[Carl Sundquist]

"Dan Connelly" <d_j_c_o_n_n_e_l@y_a_h_o_o_._c_o_m> wrote in message
news:[email protected]...
> Howard Kveck wrote:
>> In article <[email protected]>,
>> Dan Connelly <d_j_c_o_n_n_e_l@y_a_h_o_o_._c_o_m> wrote:
>>> Consider a 250 meter track, with 150
>>> meters in corners, and 100 meters in straights. If the corners are
>>> semicircular, they have a radius of R = (150 meters / 2 pi). If the
>>> bike center-of-mass (COM) is going v = 60 km/hr = 16.7 m/sec, it is
>>> experiencing a centrifugal acceleration relative to gravity of (v^2/R g)
>>> = 1.19 (I'll define this as alpha).
>
>> Thanks for the calculations, Dan.
>>
>
> Thanks...
>
> Actually, the most interesting aspect to me is that the cyclist is pulling
> sqrt(1 + alpha^2) = 1.55 g's in the corner. For me, that's an extra 70lb
> or so on top of 125. Ouch.
>
> Dan
>

And that's for the radius you calculated. Even higher on a smaller track (at
the same speed) although to get technical about it, at a certain point the
radius tends to diminish less and the straights more to help control speed.

 

[Stu Fleming]

Dan Connelly wrote:

> Actually, the most interesting aspect to me is that the cyclist is
> pulling sqrt(1 + alpha^2) = 1.55 g's in the corner. For me, that's an
> extra 70lb or so on top of 125. Ouch.

....provided that you can do 60kph into and through the corner.

 

[William Asher]

Stu Fleming wrote:

> Dan Connelly wrote:
>
>> Actually, the most interesting aspect to me is that the cyclist is
>> pulling sqrt(1 + alpha^2) = 1.55 g's in the corner. For me, that's an
>> extra 70lb or so on top of 125. Ouch.
>
> ...provided that you can do 60kph into and through the corner.

And that's even harder than you think because everybody knows you slow down
through the corners.

--
Bill Asher

 

[Dan Connelly]

Stu Fleming wrote:
> Dan Connelly wrote:
>
>> Actually, the most interesting aspect to me is that the cyclist is
>> pulling sqrt(1 + alpha^2) = 1.55 g's in the corner. For me, that's an
>> extra 70lb or so on top of 125. Ouch.
>
> ...provided that you can do 60kph into and through the corner.

Good point .

How about 40 kph?

Dan