Re: RH/L:H pedal threads

[[email protected]]

Leo Lichtman writes:

> Why are pedals threaded RH on the right side, and LH on the left
> side? If the idea is to keep the pedals from working loose as you
> ride, I think they've got it backwards. The torque applied to the
> pedal shafts by the bearing friction, in the existing system, tends
> to loosen them. But that friction is so low compared to the
> tightness of a properly installed pedal that I don't think you could
> unscrew a pedal by spinning it.

> What am I missing? They used to have left handed lug nuts on cars,
> and they don't do that anymore. Could bicycle technology be THAT
> far behind?

http://www.sheldonbrown.com/brandt/left.html

Cars stopped doing that when they went to conical lug nuts. Bicycles
could do likewise if they redesigned pedal spindles to have conical
faces. This would have two benefits, one that the pedals would not
unscrew, and the other that cranks would not break out in the pedal
eye from constant fretting.

http://www.sheldonbrown.com/brandt/breaking-cranks.html

[email protected]

 

[Jim Smith]

[email protected] writes:

> Cars stopped doing that when they went to conical lug nuts. Bicycles
> could do likewise if they redesigned pedal spindles to have conical
> faces. This would have two benefits, one that the pedals would not
> unscrew, and the other that cranks would not break out in the pedal
> eye from constant fretting.

I'm curious about that. I remember a car I had about 20 years ago
which had centerline brand aluminum wheels. The lug nuts were not
conical, but had a shoulder that fit inside the hole in the rim. Are
aluminum rims still made like that? if so, are the left side lugs
prone to loosening?

 

[jim beam]

[email protected] wrote:
> Leo Lichtman writes:
>
>
>>Why are pedals threaded RH on the right side, and LH on the left
>>side? If the idea is to keep the pedals from working loose as you
>>ride, I think they've got it backwards. The torque applied to the
>>pedal shafts by the bearing friction, in the existing system, tends
>>to loosen them. But that friction is so low compared to the
>>tightness of a properly installed pedal that I don't think you could
>>unscrew a pedal by spinning it.
>
>
>>What am I missing? They used to have left handed lug nuts on cars,
>>and they don't do that anymore. Could bicycle technology be THAT
>>far behind?
>
>
> http://www.sheldonbrown.com/brandt/left.html
>
> Cars stopped doing that when they went to conical lug nuts. Bicycles
> could do likewise if they redesigned pedal spindles to have conical
> faces. This would have two benefits, one that the pedals would not
> unscrew, and the other that cranks would not break out in the pedal
> eye from constant fretting.

link fretting & fatigue in terms that do not resemble mere coincidence
if you please. just like your dye penetrant test that supposedly
"proved" rim cracking was due to anodizing, you're missing huge lumping
great parts of the picture here and drawing tenuous connections based on
pure supposition. show us just one single modern campy or dura-ace
crank that's broken at the pedal eye, and then try discounting improved
metallurgy having elimiated the problem. the "fretting" issue of course
remains identical on all modern era cranks as it does for the old ones
on which you're relying for "evidence".

>
> http://www.sheldonbrown.com/brandt/breaking-cranks.html
>
> [email protected]

 

[Werehatrack]

On Sat, 09 Apr 2005 03:13:52 GMT, [email protected]
wrote:

>Leo Lichtman writes:
>
>> What am I missing? They used to have left handed lug nuts on cars,
>> and they don't do that anymore. Could bicycle technology be THAT
>> far behind?
>
>http://www.sheldonbrown.com/brandt/left.html
>
>Cars stopped doing that when they went to conical lug nuts.

Chrysler continued to use LH threads with conical-face lug nuts as
late as the '70s, long after Ford, GM and AMC had abandoned the
practice. They dropped the practice when they began developing FWD
vehicles, if I recall correctly.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Werehatrack]

On Fri, 08 Apr 2005 22:36:23 -0500, Jim Smith <[email protected]>
wrote:

>[email protected] writes:
>
>> Cars stopped doing that when they went to conical lug nuts. Bicycles
>> could do likewise if they redesigned pedal spindles to have conical
>> faces. This would have two benefits, one that the pedals would not
>> unscrew, and the other that cranks would not break out in the pedal
>> eye from constant fretting.
>
>I'm curious about that. I remember a car I had about 20 years ago
>which had centerline brand aluminum wheels. The lug nuts were not
>conical, but had a shoulder that fit inside the hole in the rim. Are
>aluminum rims still made like that? if so, are the left side lugs
>prone to loosening?

Some aftermarket rims are still made that way. It sucks. Yes, the
left wheels tend to loosen. No automotive factory-original alloy
wheel made in the past 30 years has used flat-face lug nuts, though
it's possible that some heavy equipment and heavy truck wheels still
do; the issues there are somewhat different due to the high loads.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

 

[Pat Lamb]

Bob wrote:
>
> Not where I go but that might be country/locale dependent. The Tire
> shop is legally obligated to tighten the wheel to the manufacturers
> specifications. Smart shops do tell you in writing that alloy wheels
> should be re-torqued after 200 miles. (FYI, and OT, don't use shops
> that don't use a torque wrench to tighten your alloy wheel lugs).

You mean there's a tire shop that doesn't tighten lugs with an air
impact wrench??