x-post: Bike Biz: Wheel ejection theory goes legal

In article ,
wrote:

Ben C? writes:

Caster is called "trail" on bikes: it's the distance from the
projection of the steering pivot to the contact patch in the
forwards axis (not the sideways axis, which is scrub).

Is it really? Wouldn't caster for a car correspond to head tube
angle for a bike?

This is something I've never been 100% clear about.

People talk about trail on bikes, not caster. AIUI trail is the
offset from the projection of the head tube (which is the steering
pivot) onto the ground back to the contact point of the tyre.

Trail is a function of head tube angle, but also of fork
rake. Increase fork rake and you reduce trail for a given head tube
angle.

OK, how about defining rake and its effect on trail instead of tossing
out vague references. Keep in mind the definition given in English:

http://www.m-w.com/dictionary/rake

rake(3) being the one in question.

Here is a good reference for these matters.
http://www.kreuzotter.de/deutsch/lenk.htm
http://www.kreuzotter.de/english/elenk.htm

--
Michael Press

On Feb 17, 10:15 am, wrote:
On Sat, 17 Feb 2007 02:16:37 -0600, Ben C wrote:
On 2007-02-17, wrote:
Ben C? writes:

Caster is called "trail" on bikes: it's the distance from the
projection of the steering pivot to the contact patch in the
forwards axis (not the sideways axis, which is scrub).

Is it really? Wouldn't caster for a car correspond to head tube
angle for a bike?

This is something I've never been 100% clear about.

People talk about trail on bikes, not caster. AIUI trail is the
offset from the projection of the head tube (which is the steering
pivot) onto the ground back to the contact point of the tyre.

Trail is a function of head tube angle, but also of fork
rake. Increase fork rake and you reduce trail for a given head tube
angle.

OK, how about defining rake and its effect on trail instead of tossing
out vague references. Keep in mind the definition given in English:

http://www.m-w.com/dictionary/rake

rake(3) being the one in question.

Someone previously posted this page, with a good diagram, which was what
I was thinking of:

http://www.kreuzotter.de/english/elenk.htm

and I'm glad to see I remembered the definitions of "trail" and "fork
rake" about right.

[snip]

Dear Ben,

That diagram is worth a thousand words.

As usual, the wheels don't care about our lexicographical arguments.

As far as I can tell, anyone discussing rake and trail on RBT will be
most helpful if he explains in passing which meanings he has in mind
and move on to his real point about the effect of the geometry on
handling.

I cannot off-hand think of any common meaning that has been changed by
appeals to dictionary sub-headings.

Jobst is funny that way - by using engineering jargon, he claims that
wheels "stand" on spokes.

Fine wordplay, but detrimental to anything but having a usenet
argument.

I find it hilariously ironic every time he complains about word use.

E.P.

In article
.com
,
wrote:

On Feb 13, 11:19 pm, Michael Press wrote:
In article
,
Can we get the thread tree display from gg?

Yes, you can get the thread-tree display from Google Groups for a link
like this to an individual message:

http://groups.google.com/group/rec.b...73416d9e457b72

Near the top of an individual-message page will be a heading "Message
from discussion whatever-the-thread-title-is"

In this case, it's "Message from Custom fork- wheel ejection risk?"

Click on the topic, and you'll go to the thread itself from the
individual message:

http://groups.google.com/group/rec.b...73416d9e457b72

The above url does indeed put up a tree view for me.
When I search for another thread, clicking on the
thread name does not bring up the tree on my
configuration. Instead I get a list of messages only.
http://groups.google.com/group/sci.math/browse_thread/t
hread/7dd49d97f7649861/61f9a91a3c8e3343?#61f9a91a3c8e334
3

_However_, when I manually substitute in this url:
s/browse_thread/browse_frm/
http://groups.google.com/group/sci.math/browse_frm/thre
ad/7dd49d97f7649861/61f9a91a3c8e3343?#61f9a91a3c8e3343
I get the tree view.

Behold, thou helmet warriors, what a dedicated sci.math
crank can accomplish. And this is not the only
concurrent thread.

--
Michael Press