indexed steering and handling?

[John Albergo]

The FAQ item states "...there is no possibility of injury or damage from 'indexed' steering head
bearings". - I would take that to imply no adverse effects on handling. However I have been noticing
sometimes squirelly handling in low speed maneuvers and can find nothing to blame it on other than
my steering has become heavily indexed.

The hub bearings turn freely with no appreciable play, tires are in good shape. Wheels are true
enough and alignment looks okay. No serious falls. I see no frame cracks. I don't think I've
developed any balance problems.

Is it possible for an indexed headset to introduce handling problems during low-speed turns where
the front wheel is actually involved in "steerng"?

 

[David L. Johnso]

On Thu, 06 Feb 2003 17:51:29 -0500, John Albergo wrote:

> The FAQ item states "...there is no possibility of injury or damage from 'indexed' steering head
> bearings". - I would take that to imply no adverse effects on handling. However I have been
> noticing sometimes squirelly handling in low speed maneuvers and can find nothing to blame it on
> other than my steering has become heavily indexed.
>
> The hub bearings turn freely with no appreciable play, tires are in good shape. Wheels are true
> enough and alignment looks okay. No serious falls. I see no frame cracks. I don't think I've
> developed any balance problems.
>
> Is it possible for an indexed headset to introduce handling problems during low-speed turns where
> the front wheel is actually involved in "steerng"?

Yeah, probably. But we are talking about slow speeds, where injury is not a big risk.

There are cures for indexed steering. Re-pack the headset with loose balls rather than the usual
bearing cage, and add one more ball than was there before. Really, replace them all, but put an
extra in. If that doesn't work, the next step is to knock out the cups and re-install them.

--

David L. Johnson

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

 

[Jobst Brandt]

John Albergo writes:

> Is it possible for an indexed headset to introduce handling problems during low-speed turns where
> the front wheel is actually involved in "steering"?

Only when riding no-hands and only after the slack has been taken out so that it "indexes" to a
preferred position. Otherwise, the clunk when braking on uneven surfaces is highly disturbing to
the rider.

Jobst Brandt [email protected] Palo Alto CA

 

[Scic]

>From: John Albergo

>Is it possible for an indexed headset to introduce handling problems during
low-speed turns where the front wheel is actually involved in steerng"?

It's not so much a "handling" problem as it is a balance problem. A bike needs to lean to turn with
stability. At low speed, turning the wheel creates instability, i.e., you're forcing it to lean but
there is not enough forward momentum to keep it from falling over. The squirelliness is the result
of balance adjustments needed to keep the bike upright. Ever notice how you regain stability in a
very low speed turn by merely pushing hard on a pedal?

Sig Chicago

 

[Jobst Brandt]

Sig snipes anonymously:

>> Is it possible for an indexed headset to introduce handling problems during low-speed turns where
>> the front wheel is actually involved in steering"?

> It's not so much a "handling" problem as it is a balance problem. A bike needs to lean to turn
> with stability. At low speed, turning the wheel creates instability, i.e., you're forcing it to
> lean but there is not enough forward momentum to keep it from falling over. The squirelliness is
> the result of balance adjustments needed to keep the bike upright. Ever notice how you regain
> stability in a very low speed turn by merely pushing hard on a pedal?

That's the greatest compendium of gobbledygook on bicycle stability seen here in a long time.
Balancing a bicycle is a dynamic exercise that goes into static balance as forward motion approaches
zero. Then it becomes a track stand, aka body balancing. "Pushing hard on the pedal" aka
accelerating is a dynamic effect that causes centrifugal acceleration, the means by which a single
track vehicle is balanced.

So back to the question. What effect does a dimpled head bearing have on control?

Jobst Brandt [email protected] Palo Alto CA

 

[Jobst Brandt]

Sig snipes anonymously:

>> Is it possible for an indexed headset to introduce handling problems during low-speed turns where
>> the front wheel is actually involved in steering"?

> It's not so much a "handling" problem as it is a balance problem. A bike needs to lean to turn
> with stability. At low speed, turning the wheel creates instability, i.e., you're forcing it to
> lean but there is not enough forward momentum to keep it from falling over. The squirelliness is
> the result of balance adjustments needed to keep the bike upright. Ever notice how you regain
> stability in a very low speed turn by merely pushing hard on a pedal?

That's the greatest compendium of gobbledygook on bicycle stability seen here in a long time.
Balancing a bicycle is a dynamic exercise that goes into static balance as forward motion approaches
zero. Then it becomes a track stand, aka body balancing. "Pushing hard on the pedal" causing
acceleration is dynamic and causes centrifugal acceleration, the means by which a single track
vehicle is balanced.

So back to the question. What effect does a dimpled head bearing have on control?

Jobst Brandt [email protected] Palo Alto CA

 

[John Albergo]

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Scic wrote:

>>From: John Albergo
>>
>>
>
>
>
>>Is it possible for an indexed headset to introduce handling problems during
>>
>>
>low-speed turns where the front wheel is actually involved in steerng"?
>
>It's not so much a "handling" problem as it is a balance problem. A bike needs to lean to turn with
>stability. At low speed, turning the wheel creates instability, i.e., you're forcing it to lean but
>there is not enough forward momentum to keep it from falling over. The squirelliness is the result
>of balance adjustments needed to keep the bike upright. Ever notice how you regain stability in a
>very low speed turn by merely pushing hard on a pedal?
>
>
I'm not talking about the increased balance demands of a slow bike. There are vague discontinuities
when negotiating slow turns that seem to have developed. My balance seems ok; at least I can walk
around in the dark with my eyes closed, stand on one leg with eyes closed, turning my head about
and so forth. I don't seem to have balance issues in other realms, just these squirrely moments in
slow turns.

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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title></title>
</head> <body> <br> <br> Scic wrote:<br> <blockquote type="cite"
cite="[email protected]"> <blockquote type="cite"> <pre
wrap="">From: John Albergo </pre> </blockquote> <pre wrap=""><!----> </pre> <blockquote
type="cite"> <pre wrap="">Is it possible for an indexed headset to introduce handling problems
during </pre> </blockquote> <pre wrap=""><!---->low-speed turns where the front wheel is actually
involved in steerng"?

It's not so much a "handling" problem as it is a balance problem. A bike needs to lean to turn with
stability. At low speed, turning the wheel creates instability, i.e., you're forcing it to lean but
there is not enough forward momentum to keep it from falling over. The squirelliness is the result
of balance adjustments needed to keep the bike upright. Ever notice how you regain stability in a
very low speed turn by merely pushing hard on a pedal? </pre> </blockquote> I'm not talking about
the increased balance demands of a slow bike. There are vague discontinuities when negotiating
slow turns that seem to have developed. My balance seems ok; at least I can walk around in the
dark with my eyes closed, stand on one leg with eyes closed, turning my head about and so forth.
I don't seem to have balance issues in other realms, just these squirrely moments in slow
turns. <br> </body> </html>

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[John Albergo]

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[email protected] wrote:

>John Albergo writes:
>
>
>
>>Is it possible for an indexed headset to introduce handling problems during low-speed turns where
>>the front wheel is actually involved in "steering"?
>>
>>
>
>Only when riding no-hands and only after the slack has been taken out so that it "indexes" to a
>preferred position. Otherwise, the clunk when braking on uneven surfaces is highly disturbing to
>the rider.
>
>
No clunks and it definitely has a preferred position; or rather several. Straight ahead and then
about 30' and 60' on both sides. With bike raised and level I can push the wheel up to about 10' to
the side and it will return on its own. Push a little further and it will continue to the next stop.
It's difficult to walk the bike by pushing the seat because you have to give it a good swing to get
the wheel to move. This is quite noticeable since I negotiate a tight hallway with two 90' turns
twice a day. Pushing the seat and tilting used to work fine now I have to reach forward and
manipulate the steerer. The road handling issues are with hands on though. If there is odd movement
somewhere else I can't find it. The advantage is that parking is more stable when leaning the bike
against a pole, etc. Reminds me of my old flick-stand.

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<br> <br> <a class="moz-txt-link-abbreviated"
href="mailto:[email protected]">[email protected]</a> wrote:<br>
<blockquote type="cite" cite="[email protected]"> <pre wrap="">John
Albergo writes:

</pre> <blockquote type="cite"> <pre wrap="">Is it possible for an indexed headset to introduce
handling problems during low-speed turns where the front wheel is actually involved in "steering"?
</pre> </blockquote> <pre wrap=""><!----> Only when riding no-hands and only after the slack has
been taken out so that it "indexes" to a preferred position. Otherwise, the clunk when braking on
uneven surfaces is highly disturbing to the rider. </pre> </blockquote> No clunks and it
definitely has a preferred position; or rather several. Straight ahead and then about 30'
and 60' on both sides. With bike raised and level I can push the wheel up to about 10' to
the side and it will return on its own. Push a little further and it will continue to the
next stop. It's difficult to walk the bike by pushing the seat because you have to give it a
good swing to get the wheel to move. This is quite noticeable since I negotiate a tight
hallway with two 90' turns twice a day. Pushing the seat and tilting used to work fine now I
have to reach forward and manipulate the steerer. The road handling issues are with hands on
though. If there is odd movement somewhere else I can't find it. The advantage is that
parking is more stable when leaning the bike against a pole, etc. Reminds me of my old
flick-stand.<br> <br> <br> </body> </html>

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[Ron Hardin]

Scic wrote:
> A brinelled (pitted, dented) crown race or lower cup will give you notched steering but not
> instability as long as your hands are on the bars.

No-handed, you have to repeatedly turn one way or the other to go straight; the no-handed turns are
fine but the bike is unstable going straight until it's fallen far enough to force you to produce a
fairly large countersteer each time. You can't do small countersteers, is the problem.
--
Ron Hardin [email protected]

On the internet, nobody knows you're a jerk.

 

[Jobst Brandt]

anonymous writes:

>> I don't seem to have balance issues in other realms, just these squirrely moments in slow turns.

> I know your sense of balance isn't the problem. A brinelled (pitted, dented) crown race or lower
> cup will give you notched steering but not instability as long as your hands are on the bars.

Hey! Enough of this BS myth and lore. No wonder you snipe from anonymity.

> Have you had the headset overhauled recently? Have you (or anyone else) crashed? Or hit something
> hard, perhaps a curb? I would suggest you remove the fork and check if the steerer tube has been
> bent at the crown. Also check that the crown race and lower cup are seated square to the steerer
> and headtube.

http://draco.acs.uci.edu/rbfaq/FAQ/8f.13.html

Jobst Brandt [email protected] Palo Alto CA