Re: Spoke Tension Increase During Stress Relieving

[Joe Riel]

[email protected] writes:

> It isn't mentioned in your pdf, but we've been tossing
> around a figure of 100 lbf for the force of one hand
> squeezing a pair of spokes.
>
> I'll take the blame for this figure. A squeeze of a bathroom
> scale did indicate around 200 pounds for me with some
> posters presumably more and others less.
>
> But I now suspect that the real world force is closer to
> only 50 pounds per squeeze, not 100 pounds.
>
> My reasoning is that the one-time squeeze on a bathroom
> scale while watching the needle and trying to avoid looking
> feeble to other posters is likely to be considerably higher
> than the 9th squeeze with the weaker hand in the 30 to 60
> seconds that it takes to work two-handed around a 36-spoke
> wheel.

Carl [gorilla grip] Fogel,

I wonder how accurate the bathroom scale is when being help and
squeezed. I just tried doing that with a digital bathroom scale
(quite accurate when used as intended) and could register a mere 70lbs
(with both hands). I suspect that my grip strength is a bit more than
35 pounds. The design of the scale (flat, with no way to close one's
hand) probably limits the force. Yeah, that must be it. And my
palms were a little sweaty, and I hadn't warmed up...

Here is a link that gives averages (in kgs) for males and females.

http://www.topendsports.com/testing/tests/handgrip.htm

Joe

 

[[email protected]]

On Wed, 29 Jun 2005 22:05:50 GMT, Joe Riel
<[email protected]> wrote:

>[email protected] writes:
>
>> It isn't mentioned in your pdf, but we've been tossing
>> around a figure of 100 lbf for the force of one hand
>> squeezing a pair of spokes.
>>
>> I'll take the blame for this figure. A squeeze of a bathroom
>> scale did indicate around 200 pounds for me with some
>> posters presumably more and others less.
>>
>> But I now suspect that the real world force is closer to
>> only 50 pounds per squeeze, not 100 pounds.
>>
>> My reasoning is that the one-time squeeze on a bathroom
>> scale while watching the needle and trying to avoid looking
>> feeble to other posters is likely to be considerably higher
>> than the 9th squeeze with the weaker hand in the 30 to 60
>> seconds that it takes to work two-handed around a 36-spoke
>> wheel.
>
>Carl [gorilla grip] Fogel,
>
>I wonder how accurate the bathroom scale is when being help and
>squeezed. I just tried doing that with a digital bathroom scale
>(quite accurate when used as intended) and could register a mere 70lbs
>(with both hands). I suspect that my grip strength is a bit more than
>35 pounds. The design of the scale (flat, with no way to close one's
>hand) probably limits the force. Yeah, that must be it. And my
>palms were a little sweaty, and I hadn't warmed up...
>
>Here is a link that gives averages (in kgs) for males and females.
>
>http://www.topendsports.com/testing/tests/handgrip.htm
>
>Joe

Dear Joe,

One trick that helps is to hold the scale lengthwise, ninety
degrees off, which lets you spread your hands further apart.
The test involved one hand hanging comfortable by your side,
not both arms angled inward at a bad angle for a
surprisingly narrow scale.

As you noticed, the thickness of the scale can be a problem,
so another trick is to have an ancient but still accurate
scale that's thicker than the sleek new modern models--the
thinner the scale, the harder it is to squeeze. (Look how
far apart the spokes are.)

The real trick, however, is work or play that involves grip.
Alas, neither bicycling nor typing on newsgroups does much
for the hand grip.

A few weeks ago, I saw my 80-year-old pediatrician. He
worked on the docks in his youth and still has an impressive
handshake.

I also know a burly motorcycle mechanic on the wrong side of
60 whose forearms are easily as big as my calves. (Step one
in many small engine repairs is to ease the hundred-pound
engine up and then sideways out of the frame--there's often
as much as an inch of clearance.)

If you look at the hands and forearms around a typical
lumber yard, you'll be tempted to bring bananas next time.

I doubt that anyone is going to squeeze as hard on the 9th
try as he did on his first attempt.

That page's average-grip of ~50kg for one hand puts 200 lbs
with both hands down around below-average to poor.

Their figures seem to be roughly normal. Here's an html
version of a similar table for both hands:

http://66.102.7.104/search?q=cache:...ENGTHTESTNORMS.doc+"hand+grip"+average+&hl=en

Even if the average maximum squeeze for 2 tries with the
best hand is ~50 kg, I suspect the last 4 pairs of spokes
may feel a lot less pressure from the weaker hand after 9
squeezes in 30-60 seconds.

If nothing else, this suggests that Sheldon Brown may be
darned clever with his method of twisting the spokes with a
smooth lever where they cross and letting an old crank arm
get sore instead of his fingers.

Carl Fogel