Re: [CR]Frame Flex Testing

(Example: Production Builders:LeJeune)

Content-class: urn:content-classes:message
Subject: Re: [CR]Frame Flex Testing
Date: Wed, 28 Sep 2005 16:50:41 -0700
Thread-Topic: Re: [CR]Frame Flex Testing
Thread-Index: AcXEh29po8zWeCqXRDKaHhHiDwijlQ==
From: "KO Kevin" <>
To: <>

I was thinking the exact same thing! It is the same as claiming that the energy used to "wind-up" a spoked wheel is stored in the wheel and somehow released to the benefit of the rider. Its just wasted energy, period.

Kevin Ko Eugene, OR

Date: Wed, 28 Sep 2005 19:24:35 -0400 From: Louis Schulman <> Subject: Re: [CR]Frame Flex Testing < g %22&SearchPrefix=%40msgsubject&SortBy=MsgDate%5Ba%5D>

Well, without going to the archives, and without getting drawn into a big discussion, the argument about that energy from frame flex is conserved because bicycles are springs is rubbish.

Yes, deflecting a frame causes the frame to store energy. Yes, when the frame springs back, it releases the energy. However, this energy does not go back up the rider's legs, nor does it move the bicycle forward. It is just wasted movement.

It often appears to me that many posters on this list seem to be unaware

of basic principles of physics. Maybe we should start a physics mailing


Louis Schulman Tampa, FL wrote:
> Without getting into the testing methodology, the conclusions on the web site cited below are in my opinion useless.
> The author claims there is no downside to a frame that is too stiff. That in my opinion is just plain wrong. Again, a Raleigh 3sp is super stiff, but dead. A frame must be neither too stiff or too flexible. It

must have flex characteristics that enhance the riders pedal stroke without causing a sub-optimal amount of additional body motion.
> Without getting drawn back into discussion that is in the archives - remember that frames DO NOT absorb significant amounts of energy - they are big springs.
> The author of the frame flex tests and discussion cited below seems to

have missed this important point.


> Mike Kone in Boulder CO