L/H R/H threads on pedals

In news:[email protected],
bob <[email protected]> typed:
> Hi Im still new to cycling, so im sorry if this has been covered before but im confused.
>
> I removed the pedals from my bike today for cleaning and lubing, the right hand (as you sit on the
> bike) pedal has a normal right hand thread and the left has a left hand thread, correct?
>
> Surely that should be the other way around? I thought the idea of L/H and R/H threads was to keep
> the rotating shaft turning in a direction that always tightens them, but it doesn't.
>
> If you put a spanner on the R/H pedal shaft as if you were about to undo it, and turn the crank in
> a forward direction as if pedalling forward, keeping the spanner in a horizontal manner (like your
> foot) the pedal would unscrew, same on the left side. Or am I missing the point?
>
> BoB

The way I always remember it is to loosen hold the handle of the wrench up wards and pull toward the
rear of the bike. To put back on hold the pedal with the wrench and back spin the cranks to thread
in. ALWAYS start the threads with your fingers.

Mike

"bob" <[email protected]> wrote in message
news:[email protected]...
> Hi Im still new to cycling, so im sorry if this has been covered before but im confused.
>
> I removed the pedals from my bike today for cleaning and lubing, the right hand (as you sit on the
> bike) pedal has a normal right hand thread and the left has a left hand thread, correct?
>
> Surely that should be the other way around? I thought the idea of L/H and R/H threads was to keep
> the rotating shaft turning in a direction that always tightens them, but it doesn't.
>
> If you put a spanner on the R/H pedal shaft as if you were about to undo it, and turn the crank in
> a forward direction as if pedalling forward, keeping the spanner in a horizontal manner (like your
> foot) the pedal would unscrew, same on the left side. Or am I missing the point?
>
> BoB

You're right... but - there's an effect is called "Precession" that causes exactly the opposite to
occur. Basically, because the end of the shaft flexes and moves in a circle going the way that would
unscrew the pedals, but the end of the threads acts like a fulcrum, the threaded part of the spindle
rotates the OPPOSITE way. Crazy, but rue.

www.sheldonbrown.com has something on it, I'm too lazy to find the page right now though

Jon Bond

bob <[email protected]> wrote:
> Hi Im still new to cycling, so im sorry if this has been covered before but im confused.
>
> I removed the pedals from my bike today for cleaning and lubing, the right hand (as you sit on the
> bike) pedal has a normal right hand thread and the left has a left hand thread, correct?
>
> Surely that should be the other way around? I thought the idea of L/H and R/H threads was to keep
> the rotating shaft turning in a direction that always tightens them, but it doesn't.
>
> If you put a spanner on the R/H pedal shaft as if you were about to undo it, and turn the crank in
> a forward direction as if pedalling forward, keeping the spanner in a horizontal manner (like your
> foot) the pedal would unscrew, same on the left side. Or am I missing the point?
>
> BoB

Sheldon Browns pedal article is right here: http://www.sheldonbrown.com/gloss_p.html#pedal