Re: [CR]1975 Peugeot PR10 Geometry

(Example: Framebuilding)

Date: Thu, 18 May 2006 21:47:05 +1000
From: "P. Lynn Miller" <lynnmiller@optusnet.com.au>
To: Classic Rendezvous <classicrendezvous@bikelist.org>
Subject: Re: [CR]1975 Peugeot PR10 Geometry
References: <000101c67a6c$19c7a9d0$6401a8c0@maincomputer>
In-Reply-To: <000101c67a6c$19c7a9d0$6401a8c0@maincomputer>


Ken,

I agree with you, photos cannot be completely trusted, that is why I have asked the list for help. When I did the numbers using photoshop and illustrator, I was stunned. I have two riders so far that are confirming my numbers from actual bike take-offs.

I am very surprised at geometry. Especially if the PX10 of the same vintage has similar angles. The PX10 gets a lot of coverage here in the list and so I assumed that its geometry would be typical of the 'established' standard. But is is far from it. With a seat angle of 75 and head angle of 76, that is steeper than many track machines. One rider even mentioned that he had notice that his bike's angles seemed steeper than a fellow riders track bike when in a rack together at the coffee shop.

So I am very interested in hearing from Peugeot riders of the PR10 about the handling of the bikes compared to other bikes. Also does anyone if the PX10 had the same specs. From the photos I have seen, it would appear that way.

Does anyone know why Peugeot would have spec their bikes like this? To be different in a French way? A trend at the time? A famous racer had a bike with these angles?

Just curious,

Lynn Miller Sydney, Australia http://www.chainringtransitauthority.com / Ken Freeeman wrote:/
> /Generally I'd be cautious about measuring angles from photos. We want the
> numbers to be good to within a degree or less, and I've found the camera
> position needs to be perpendicular to the bike to see the frame tubes
> accurately. A little bit of bias causes the front and rear wheel diameters
> to "read" differently, and if I see this I tend to doubt the frame numbers I
> get.
>
> The geometry that's been estimated for this bike is odd, but if you like the
> ride, it isn't bad, right?
>
> In Tony Oliver's great book "Touring Bikes," he makes a good case that
> "proper" touring bike geometry is driven by the expected terrain and usage,
> and hence he demurs in stating any single design criterion for touring
> bikes. What he liked for his Welsh environment and customers is not
> necessarily what would work in the US or Oz. Plus, I think most riders
> acclimate to variations in handling./