Need to borrow your brains...

I just finished an article for my website addressing the front wheel disc brake issue.

But before I publish it (make it available to the public), I was wondering if some of the technical
whiz-brains of the group, those who really understand the physics behind this, could read it and let
me know if I at least got the basic principles right?

Thanks in advance. :-3)

Here's the page: http://geocities.com/czcorner/tech20.html

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner

"Chris Zacho "The Wheelman"" <ChriszCorner@webtv.net> wrote in message
news:17003-3ECABE03-947@storefull-23...wson.webtv.net...
> I just finished an article for my website addressing the front wheel disc brake issue.
>
> But before I publish it (make it available to the public), I was wondering if some of the
> technical whiz-brains of the group, those who really understand the physics behind this, could
> read it and let me know if I at least got the basic principles right?
>
> Thanks in advance. :-3)
>
> Here's the page: http://geocities.com/czcorner/tech20.html
>
> May you have the wind at your back. And a really low gear for the hills! Chris
>
> Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner
>

Pretty good Chris. I'd only say a few things. Don't limit yourself by saying there are only 2 ways
to fix the problem. I'm sure there are a dozen. No point painting yourself into a corner there. I'd
also say something like "Don't panic!". For sure there is a problem, but I don't think 15 people a
day from your shop will be eating the stem anytime soon because of this problem. As you say, check
your QR every ride (during the ride may be a bit much) and things will probably be fine. I'm sure
the industry will examine this problem and make some changes that will actually get put into
production in a year or two.

Cheers,

Scott..

Chris Zacho writes:

> I just finished an article for my website addressing the front wheel disc brake issue.

> But before I publish it (make it available to the public), I was wondering if some of the
> technical whiz-brains of the group, those who really understand the physics behind this, could
> read it and let me know if I at least got the basic principles right?

Two things occur to me when reading this web page. Why are YOU writing this? What do YOU know about
technical writing. The article takes too long getting to the point and then doesn't make it
forcefully, as though you were uncertain about the concept. The dark background for the text makes
poor reading. Get rid of that!

Jobst Brandt jobst.brandt@stanfordalumni.org Palo Alto CA

jobst.brandt@stanfordalumni.org wrote in message news:<aSCya.15693$JX2.960913@typhoon.sonic.net>...
> Chris Zacho writes:
>
> > I just finished an article for my website addressing the front wheel disc brake issue.
>
> > But before I publish it (make it available to the public), I was wondering if some of the
> > technical whiz-brains of the group, those who really understand the physics behind this, could
> > read it and let me know if I at least got the basic principles right?
>
> Two things occur to me when reading this web page. Why are YOU writing this? What do YOU know
> about technical writing.

This is rather unfair! Chris's site contains a wealth of useful information on various topics.
Interpreting and collating technical information for a non-technical audience is a very valuable
function. After all, journalists are rarely experts in the forefront of their field, while many
"experts" have difficulty putting across arguments in plain english that anyone can understand.
You don't need to be an "expert" to write about a subject so long as you have done your research
well enough.

>The article takes too long getting to the point and then doesn't make it forcefully, as though you
>were uncertain about the concept.

I disagree again. The points are clearly made in a balanced way without being sensationalist. I don
not find evidence of uncertainty here.

>The dark background for the text makes poor reading. Get rid of that!
>
I agree with this bit. Also note that "forward" is mis-spelled in the second solution.

Keep up the good work Chris.

ChriszCorner@webtv.net (Chris Zacho "The Wheelman") wrote in message
news:<17003-3ECABE03-947@storefull-2354.public.lawson.webtv.net>...
> I just finished an article for my website addressing the front wheel disc brake issue.
>
> But before I publish it (make it available to the public), I was wondering if some of the
> technical whiz-brains of the group, those who really understand the physics behind this, could
> read it and let me know if I at least got the basic principles right?

Doesn't look too bad, but I think it would be helpful to provide useful links (eg the articles on
www.velovision.co.uk, unfortunately bikebiz is password-protected but you can use google (etc) to
provide links to the articles as posted here).

But my real concern is over your advice to people to just keep riding regardless. What basis do you
have for advising this?

James

Andrew Webster <awebster@littleheath.org.uk> writes:

>>> I just finished an article for my website addressing the front wheel disc brake issue.

>>> But before I publish it (make it available to the public), I was wondering if some of the
>>> technical whiz-brains of the group, those who really understand the physics behind this, could
>>> read it and let me know if I at least got the basic principles right?

>> Two things occur to me when reading this web page. Why are YOU writing this? What do YOU know
>> about technical writing.

> This is rather unfair! Chris's site contains a wealth of useful information on various topics.

I said "THIS WEB PAGE" not his site.

> Interpreting and collating technical information for a non-technical audience is a very valuable
> function. After all, journalists are rarely experts in the forefront of their field, while many
> "experts" have difficulty putting across arguments in plain english that anyone can understand.
> You don't need to be an "expert" to write about a subject so long as you have done your research
> well enough.

You say that as though I don't address this problem daily in my postings as well as in "the Bicycle
Wheel" that addresses the same audience.

>> The article takes too long getting to the point and then doesn't make it forcefully, as though
>> you were uncertain about the concept.

> I disagree again. The points are clearly made in a balanced way without being sensationalist. I do
> not find evidence of uncertainty here.

What do you mean by balance? Either it IS a problem or it isn't. There is no balance tilting one way
or another. The problem needs to be clearly stated, expanded upon, and summarized, as any good
description should. This is not the case here.

Jobst Brandt jobst.brandt@stanfordalumni.org Palo Alto CA

Thanks for your input. It's nice to know I got the theory right. I'm not an engineer, just a
machinist with a shade-tree engineering degree. IOW, A decent mechanical intuition and a lot of time
with tools. :-3)

As to Jobst's comment, no insult is taken. If I believed I was a sooper-genius, I never would have
asked for your advice!

And the article is supposed to be oversimplified. That's the idea behind the entire site. I want to
be sure even the first time biker can understand it, without feeling overwhelmed.

As to the colors, I've never gotten that complaint before. It looks fine to me. On both my webbie
and my pc. But then, I may have them set brighter. Besides, the BG can always be turned off. I'll
look into fading the image some, though.

And I'll correct the misspell ;-3)

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner

Some thoughts about your page:

1. A quote:

"Now if your QR is properly tightened, it probably isn't enough to wrench the axle out of the
dropouts. Especially if you have the newer forks equipped with "lawyer lips' (those round
depressions that the nuts or quick release ends fit into)."

I think anyone riding a QR equipped bike with a Disk Brake (rear mounted) without Lawyer lips should
immediately stop riding it. It is possible that a properly installed wheel could immediately come
loose if there are no Lawyer Lips. My belief is that this is what happened to James Annan's bike. He
only rode it for about an hour before the wheel popped out.

2. As a foot note to the above. Roadies have a tendency to file the Lawyer Lips off a new bike. This
is clearly a poor policy in this case (and one I have argued against in general.) Any website
addessing QR disk brake issue ought to have a warning about the importance of Lawyer Lips and
advice to stop riding a QR/disk brake bike where they have been removed.

3. I think you are opening yourself to liability by suggesting that people continue to ride
these bikes. Someone reads your page, goes out and takes a tumble for whatever reason and you
are on the hook.

Riding such a bike might be your decision but in my view, you should only provide the information
and let each person make the decision for themselves.

4. You ought to provide a link to James Annan's pages so people who are interested can see some
more extensive information. This is really his baby, providing a link not only allows people to
see where this started but also gives credit where credit is due.

jon isaacs

I agree with Jobst that you need to get into the story quicker. Start with a summary and finish with
a conclusion. Just because it is written simply doesn't mean it has to be long and boring.

jonisaacs@aol.com (Jon Isaacs) wrote in message
news:<20030521184946.27374.00000084@mb-m03.aol.com>...
> 4. You ought to provide a link to James Annan's pages so people who are interested can see some
> more extensive information. This is really his baby, providing a link not only allows people
> to see where this started but also gives credit where credit is due.
>
> jon isaacs

Ho ho ho. You mean 'blame' not 'credit'. Yesterday I saw the world "Annanism" on a website - and it
wasn't "Kofi Annanism"....! It seems to me that when the journalists and others use his name (eg.
"Annan's theory") they are doing it as a way to distance themselves from 'blame'.. It's not James'
'baby' - he hasn't discovered any new physics, nor could he have written his web page without huge
input from all of us. But I do agree that the webpage should be linked into the article so that
non-numpties who happen upon this page can go somewhere for the facts.

I am just glad I did not change my name when I married him.

Hiding in Japan...

jules

James Annan wrote:

"Doesn't look too bad, but I think it would be helpful to provide useful links (eg the articles on
www.velovision.co.uk, unfortunately bikebiz is password-protected but you can use google (etc) to
provide links to the articles as posted here)."

Good Idea. I looked at the one you provided, but it looks like a "news" page (like MSN.com) IOW,
they change the articles on a daily/weekly/monthly/etc. basis. Do you know of any permanent ones?

"But my real concern is over your advice to people to just keep riding regardless. What basis do you
have for advising this?

James "

It's probably safe to continue to ride it, provided you take the proper precautions: Check the
wheels before, as well as periodically during, the ride. If you consider at the number of front disc
equipped bikes there are, it's easy to see that the percentage of wheels that have flown the coop
because of this is pretty small.

Besides, what do you expect everyone to do? Go out, buy and ride a new bike until this thing's
fixed? :-3)

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner

OK, I've tweaked it somewhat, hopefully reducing any liability:
----------------------------------------------------------------
<snip>

"So does this mean you should stop riding your ATB and send the forks back to the manufacturer for
repair or replacement?

Well, unfortunately you can't, not yet. They haven't started to incorporate any design changes as of
this writing. Some manufacturers are "looking into the problem", but you know how slow they can be
to change something they think is "tried and true". Especially if it requires redesigning or
retooling (which = $). So short of buying a new wheel and front brake set, there's nothing you can
do right now. However, if you do wish to continue riding your bike this way, realize that there is
an additional risk in doing so!

In the mean time, there are some things you can do to at least reduce the chances of your wheels
from being ejected from your forks:

>Don't file off the "lawyer lips"! They are there for a reason. If you file them off, you are
>deliberatly compromising the safety of your machine! Besides. If you do, and your wheel does come
>off, you won't have a leg to stand on in court (excuse the pun).

>Always inspect the wheels before each ride, Actually, this is good advice with any bike, regardless
>of what kind of brakes it has.

>>Is the axle in the right place? Meaning is it all the way in the dropout?

>>Are the nuts tight? or the QR properly adjusted? The lever should meet resistance halfway through
>>it's swing, meaning when it's sticking straight out from the forks, parallel to the axle. A little
>>before is O.K. After is not.

>Check them periodically during your ride. Especially after a downhill or any time after a lot of
>repeated braking. Look for the same things.

Actually check them, don't assume that just because they don't look loose, or don't ride funny that
they are all right, or that "they'll be OK for the last few miles". Because if they do fail, they
will do so catastrophically, Most likely when your braking hard. Either because you're going too
fast and really need to slow down quick, or you need to avoid a crash.

Now your quick release may never loosen, your wheel may never fly out. This has not happened to
every single ATB on (or off) the road, it may not happen to yours. Just be aware that the
possibility does exist, that that it can happen, and if you do continue to ride your bike, take the
appropriate precautions." </snip>
------------------------------------------------------------
I also lightened the BG about 50%.

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner

ChriszCorner@webtv.net (Chris Zacho "The Wheelman") wrote in message
news:<26310-3ECD6CE9-151@storefull-2355.public.lawson.webtv.net>...

> Good Idea. I looked at the one you provided, but it looks like a "news" page (like MSN.com) IOW,
> they change the articles on a daily/weekly/monthly/etc. basis. Do you know of any permanent ones?

I didn't think that anyone bothered clearing out old archives any more. Cheaper to just buy a
bigger disk.

www.ragingbike.co.uk has a short article which seems like a clear summary:

http://www.ragingbike.co.uk/news/news_item.html?id=234

and I can't imagine that anyone would object to you copying them, with attribution.

> It's probably safe to continue to ride it, provided you take the proper precautions

I doubt that you have enough information to evaluate the risk properly, I certainly don't pretend to
have more than a vague idea.

> Besides, what do you expect everyone to do? Go out, buy and ride a new bike until this thing's
> fixed? :-3)

Bear in mind that my primary goal was simply to explain the failure and prevent it from
incorrectly being automatically attributed to rider error. What others do with that information is
really up to them.

However, since you ask, I would not ride a bicycle with this design problem and if I had a fork of
this type, I would already have sent it back and demanded a refund/replacement.

James

jobst.brandt@stanfordalumni.org wrote in message news:<AdSya.15886$JX2.971774@typhoon.sonic.net>...
>
> <cut> You say that as though I don't address this problem daily in my postings as well as in "the
> Bicycle Wheel" that addresses the same audience.
>

Here you impute to me opinions I do not hold and have not expressed.

<cut>

>
> What do you mean by balance? Either it IS a problem or it isn't. There is no balance tilting one
> way or another. The problem needs to be clearly stated, expanded upon, and summarized, as any good
> description should. This is not the case here.
>

By balance I mean a discussion of the risks involved as opposed to simply the hazard. That there is
a hazard here is undoubted, the management of the risk is also clearly covered on Chris's page.

He covers what the problem is AND what to do about it - this is balanced.

("Risk" and "Hazard" here being used in the standard meanings used in risk assessment)

ChriszCorner@webtv.net (Chris Zacho "The Wheelman") wrote in message
news:<19578-3ECD77BA-72@storefull-2357.public.lawson.webtv.net>...
> OK, I've tweaked it somewhat, hopefully reducing any liability:
> ----------------------------------------------------------------
> <snip>
>
> "So does this mean you should stop riding your ATB and send the forks back to the manufacturer for
> repair or replacement?
>
> Well, unfortunately you can't, not yet. They haven't started to incorporate any design changes as
> of this writing.

False, there are many forks which do not have this problem, even if the vast majority do. For that
matter, several small tandem manufacturers have already changed their designs although these bikes
are generally intended for road use and this is not directly relevant to the wider problem. I
haven't actually seen the designs to comment on how efectively they have addressed the problem (and
anyway, I'm not qualified to judge).

> Some manufacturers are "looking into the problem",

Only one has admitted as much in public, and that was well over a week ago.

http://www.ne.jp/asahi/julesandjames.../comments.html

This isn't rocket science and the delay in further comment already seems unreasonable to me. If they
are really struggling to find any evidence in support of my assertions, you'd think they might take
the trouble to get in touch with me to follow up some of the stories I have quoted.

James