Pedal Tip

"Just zis Guy, you know?" <[email hidden]> wrote

Quoted message said:

Good lab technicians are the lifeblood of any lab and are vastly underappreciated.

Quite right.

Andy (A lab technician)

On Mon, 19 May 2003 17:03:34 GMT,

Tenex said:

Tom C said:

Darren Hall wrote

Quoted message said:

> I was quite alarmed at how knackered I was this morning. I suspect this is because I didn't eat
> much breakfast before I left (not really keen on big breakfasts).

And don't forget the mid afternoon drop of blood sugar too. You'll need something to fuel the
journey home. You're probably using about 3-400 calories on the journey back so don't worry too
much about the impact on your weight.

Tom

16 miles must surely be more than 3-400 calories??

draco.acs.uci.edu9.23.htmlOpen ↗

A 140lb rider doing 16mph on a still day on the flat - 557 cal.

Tim.

--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t," and there was light.

tjw.hn.orgtjw.hn.orgOpen ↗ locofungus.btinternet.co.uklocofungus.btinternet.co.ukOpen ↗

Pete Biggs said:

[Cross-posted to rec.bicycles.tech to get some more response.......]

Andy Dingley said:

Quoted message said:

Look up "precession" at sheldonbrown.comgloss p.htmlOpen ↗

Quoted message said:

Even Sheldon gets it wrong sometimes (although not so badly as Eric Laithwaite). There's no
precession if the axes are parallel.

Sometimes, but not this time. The axles are only parallel in theory. In practice, there's very
slight movement unless the pedals are unusually tight.

Quoted message said:

Quoted message said:

Anyone suffering from pedals falling off, with either threading ?

Not many people have actually tried incorrectly-threaded pedals. I have, because my early home-built
tandems used single-type cranks, so the threading was incorrect on 3 of the 4 pedals.

I've also run backward pedals on a fixed gear bike that I set up with the chain on the left side,
just as a hack.

I did, in fact have some trouble with pedals loosening up. This was only cured by tightening them
unusually forcefully.

The armchair theorizers often don't realize that the left-threaded left pedal was not the result of
idle reasoning. It was the solution to a persistent problem that was observed with early bicycles.
Left pedals used to be prone to falling off.

Quoted message said:

Quoted message said:

Of course the pencil precesses. But that's using an "effect-based" meaning of precession, not a
gyroscopic causality by precession's usual meaning.

Actually, the _original_ meaning of precession comes to us from astronomy, most specifically the
precession of the equinoxes.

The use of this term in dealing with tops and gyroscopes in derived from the Oldest Science.

Quoted message said:

Quoted message said:

Quoted message said:

And how do you apply force to the pedals? Nothing is parallel in the vicinity of the bottom
bracket when in use.

Quoted message said:

Quoted message said:

OK, lets assume a miniscule precessive force. But the nature of a tight threaded connection is
non-Newtonian. Applying a tiny force won't make it unscrew itself "very slowly", it just won't
begin to move at all.

If the pedal is sufficiently tight, even if threaded in the wrong direction, it won't loosen up.
However, many pedals are not tightened to this extent.

Sheldon "Left Isn't Wrong" Brown +----------------------------------+
| What sane person could live in | this world and not be crazy? | --Ursula K. LeGuin |
+----------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone 617-244-9772
FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts shipped Worldwide
captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

"Sheldon Brown" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Pete Biggs said:

[Cross-posted to rec.bicycles.tech to get some more response.......]

snp< Sheldon "Left Isn't Wrong" Brown

Yeah, but it certainly ain't right...

Jon "adding nothing to the discussion" Bond

Sheldon Brown said:

I've also run backward pedals on a fixed gear bike that I set up with the chain on the left side,
just as a hack.

I know there was a lot of gear going round in the 60's, but why?

--
Andy Morris

AndyAtJinkasDotFreeserve.Co.UK

Love this: Put an end to Outlook Express's messy quotes
home.in.tum.deoe quotefixOpen ↗

Sheldon Brown said:

Quoted message said:

I've also run backward pedals on a fixed gear bike that I set up with the chain on the left side,
just as a hack.

AndyMorris said:

I know there was a lot of gear going round in the 60's, but why?

As I said, it was a hack. I've done stranger things than that in my time.

Wait 'til you see what I've done to a Surly Karate Monkey...the Web page isn't quite ready yet, but
check harriscyclerysurly rohloffOpen ↗ in a day or two...

Sheldon "Bicycle Hacker" Brown +-----------------------------------------------------------+
| Oh, my ways are strange ways and new ways and old ways, | And deep ways and steep ways and high
| ways and low, | I'm at home and at ease on a track that I know not, | And restless and lost on a
| road that I know. | --Henry Lawson, Australian poet. |
+-----------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts
shipped Worldwide captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

AndyMorris said:

Sheldon Brown said:

I've also run backward pedals on a fixed gear bike that I set up with the chain on the left
side, just as a hack.

I know there was a lot of gear going round in the 60's, but why?

I can't answer for Sheldon-- but for some of us, being contrary is one of the simple
pleasures in life.

Tom Ace

Andy Dingley said:

Anyone suffering from pedals falling off, with either threading ?

It's not unknown. One of the peculiarities of the soi-disant Kingcycle K-Drive is that the pedal
rotates the opposite way relative to the crank from normal, God-fearing bicycles. Ian Chattington
found this out the hard way while racing Nigel Sleigh's Wasp II. The pedal apparently fell off. Ian
vacated the bike to find it, but could not. Accordingly he ran back to his van to get a spare. Only
on his return to the abandoned bike did he find the errant pedal still firmly attached to the
underside of his shoe...

Dave Larrington - legslarry.beerdrinkers.co.uklegslarry.beerdrinkers.co.ukOpen ↗
===========================================================
Editor - British Human Power Club Newsletter
bhpc.org.ukbhpc.org.ukOpen ↗
===========================================================

Quoted message said:

Quoted message said:

Sheldon Brown said:

I've also run backward pedals on a fixed gear bike that I set up with the chain on the left side,
just as a hack.

AndyMorris said:

I know there was a lot of gear going round in the 60's, but why?

Tom Ace said:

I can't answer for Sheldon-- but for some of us, being contrary is one of the simple pleasures
in life.

No way! Absolutely not! Well, maybe...

Sheldon "Contrarian" Brown +---------------------------------------------------------+
| "Contrariwise," continued Tweedledee, "if it was so, | it might be, and if it were so, it would
| be; | but as it isn't, it ain't. That's logic!" | --Lewis Carroll, "Through the Looking Glass" |
+---------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 harriscyclery.comharriscyclery.comOpen ↗ Hard-to-find parts
shipped Worldwide captainbike.comcaptainbike.comOpen ↗ sheldonbrown.comsheldonbrown.comOpen ↗

Sheldon Brown said:

Pete Biggs said:

[Cross-posted to rec.bicycles.tech to get some more response.......]

Andy Dingley said:

> Look up "precession" at sheldonbrown.comgloss p.htmlOpen ↗

Quoted message said:

Even Sheldon gets it wrong sometimes (although not so badly as Eric Laithwaite). There's no
precession if the axes are parallel.

Sometimes, but not this time. The axles are only parallel in theory. In practice, there's very
slight movement unless the pedals are unusually tight.

Quoted message said:

Quoted message said:

Anyone suffering from pedals falling off, with either threading ?

Not many people have actually tried incorrectly-threaded pedals. I have, because my early
home-built tandems used single-type cranks, so the threading was incorrect on 3 of the 4 pedals.

I've also run backward pedals on a fixed gear bike that I set up with the chain on the left side,
just as a hack.

I did, in fact have some trouble with pedals loosening up. This was only cured by tightening them
unusually forcefully.

The armchair theorizers often don't realize that the left-threaded left pedal was not the result
of idle reasoning. It was the solution to a persistent problem that was observed with early
bicycles. Left pedals used to be prone to falling off.

Bottom bracket cups experience a similar precession effect, which is why English/ISO threaded bottom
brackets use a left-hand thread on the right side cup.

Again, this was not done due to some idle theory, but a solution to problem of right side BB cups
with right-hand threads constantly loosening. This propensity to loosen is still seen today with the
right side cups of Italian threaded BBs (which have a right-hand thread right cup), unless they
screwed in very, very tightly. The left-thread on the right side cup of English/ISO BBs are quite
effective at solving this problem.

Mark McMaster [email hidden]