I measure it the same way, and all the guys I've met have done it that way
to, being fairly consistent.
On those odd frame sizes it's fairly easy to interpolate where the wheel
center would be.
It takes a little common sense, but our bike guys have quite abit of that or
they wouldn't be in the game.
Newer guys will learn quickly with the good experienced tips, which is why
we're here.
Ted Ernst
Palos Verdes Estates
CA, USA
<classicrendezvous@bikelist.org> Sent: Sunday, May 20, 2007 5:29 PM Subject: Re: [CR]Was: intro... now: frame geometry
> << I tend to like the stay intersection method for both chainstay and
> wheelbase, but that's really just because it gives me a way to find the
> measurement point, and to be consistent in my own work. >>
>
> That makes sense.
> The only problem I could possible see with that seat & chain
> stay-intersection idea, is that on extremely large and small frames those
> seat stays may point to strange places (so to speak).
> But I haven't heard a better approach!
>
>
> Dale Brown
> Greensboro, North Carolina USA
>
>
>
>
>
>
> -----Original Message-----
> From: freesound@comcast.net
> To: oroboyz@aol.com; damann@mitre.org; classicrendezvous@bikelist.org
> Sent: Sun, 20 May 2007 8:20 PM
> Subject: RE: [CR]Was: intro... now: frame geometry
>
> I think CR had this "standards" discussion quite a while back, and it was
> not possible as I recall to come to a consensus on chainstay. My strongest
> recollection, which is weak, is that it was necessary to declare the
> measurement conventions you use (where significant) if you publish frame
> measurements. The most significant questions in getting and comparing
> measurements are related to seat tube/frame size, chainstay length, and
> teh entire head tube and fork areas. I have to admit I worked with Dave
> just a little bit on a contribution to his website, a short article on a
> method for measuring frames using simple tools. My method is not free of
> error, but it can be applied consistently. It does not have the certainty
> that a skilled framebuilder can achieve using precision tools on a
> reference table. I'm sure of this because I had the priveledge of watching
> Doug Fattic work one day. I tend to like the stay intersection method
> for both chainstay and wheelbase, but that's really just because it gives
> me a way to find the measurement point, and to be consistent in my own
> work. Ken Freeman Ann Arbor, MI USA
> From: oroboyz@aol.com [mailto:oroboyz@aol.com]
> Sent: Sunday, May 20, 2007 7:28 PM
> To: freesound@comcast.net; damann@mitre.org;
> classicrendezvous@bikelist.org
> Subject: Re: [CR]Was: intro... now: frame geometry
>
> << I really don't see any basis for preferring one way over another, but
> maybe someone else does ... ? >>Sure, no strong opinion from me about
> which is "right", but w/o an agreed upon standard, it hurts communication
> if everyone is talking about something different... Dale Brown
> Greensboro, North Carolina USA
>
>
>
>
>
> -----Original Message-----
> From: freesound@comcast.net
> To: oroboyz@aol.com; damann@mitre.org; classicrendezvous@bikelist.org
> Sent: Sun, 20 May 2007 6:51 PM
> Subject: RE: [CR]Was: intro... now: frame geometry
>
> As a friend of Dave's, Dale I'm glad to see you like his work.
>
> Regarding chainstay, here's another method: measure from the center of the
> crank to the point where the seatstay and chainstay centerlines intersect,
> if the axle slot allows it. I think Trek did it this way in their early
> days.
>
> One of the problems with looking for a "logical" location or just
> measuring
> to the actual axle position (yes, a 5th option!) is that the best wheel
> installation position, in a slotted dropout, can be a result of gearing
> choice. When fitting a 13-26 to my short-short Masi, I have to tweak the
> wheel position and the chain length together to optimize shifting. (can
> do,
> but not sure it's worth the trouble!!) Of course this situation is not
> limited to Masi's!
>
> I really don't see any basis for preferring one way over another, but
> maybe
> someone else does ... ?
>
> Ken Freeman
> Ann Arbor, MI USA
>
> -----Original Message-----
> From: classicrendezvous-bounces@bikelist.org
> [mailto:classicrendezvous-bounces@bikelist.org] On Behalf Of
> oroboyz@aol.com
> Sent: Sunday, May 20, 2007 5:19 PM
> To: damann@mitre.org; classicrendezvous@bikelist.org
> Subject: [CR]Was: intro... now: frame geometry
>
> Welcome Dan, you sound like you are a super addition to our strange
> assembly of cycling aficionados!
>
> The frame geometry web site shown on your e-mail signature interested me..
>
> http://home.comcast.net/
>
> Pretty much fun trying to catalog and categorize that information!
>
> My first thoughts were how bikes with almost-the-same geometry (assuming
> "identical" is impossible) often "seem" to ride differently... The whole
> process of "ride" is so subjective and not able to be measured. Lordy,
> many
> have tried and tried to evaluate "ride" but it is still an elusive art...
>
> The other thought that might be fun to hear others discuss is that of
> chain
> stay length, or rather, how one measures that dimension on horizontal drop
> out bike frames (road, not addressing track dropouts) ...
>
> You suggest measuring to the linear extensions of the seat & chain stays/
> Other approachs:
> - The mathmatical mid point in the drop out slot.
> - The center of the derailleur hanger (McLean Fonvielle used this method.)
> - The spot where the rear axle might most logically be positioned (hard to
> say sometimes!)
>
> Are there other approaches?
>
> Dale Brown
> Greensboro, North Carolina USA
>
>
> -----Original Message-----
> From: damann@mitre.org
> To: classicrendezvous@bikelist.org
> Sent: Sun, 20 May 2007 2:59 PM
> Subject: [CR]New Member Intro
>
> Hey folks,
>
> I've just joined the list so I thought I would post up my official
> introduction post.
>
> My name is Dave Mann and I live in the Boston area.
>
> I got into bikes when I was in high school in central Ohio. A kindly guy
> who ran the local bike shop talked me through the task of renovating my
> suffering bike. When I was finished and got it working well enough, he
> offered me a job in his shop. That was 30 years ago.
>
> That kind soul's name is Chuck Harris. And while the shop has been
> closed,
> I'm glad report that he's still producing and selling his wonderful
> mirrors.
>
> Chuck was a huge influence in my cycling. The first time I rode from one
> town to another was one a group ride. And I still remember the day he
> dropped everything he was working on to help a coast-coast tourist who
> limped into town with a blown bottom bracket. Those experiences expanded
> my
> horizons about riding which eventually led me to the wonderful world of
> bike
> touring.
>
> I'm insanely interested in lightweight sport touring bikes.
> Especially the early Japanese and American frames and great Japanese
> components.
>
> This is firmly based in the first experiences selling and working on
> Japanese Fujis and Miyatas in Chuck's shop. It's also based on the set of
> bikes that I've owned which has
> included:
> 1978 Fuji Grand Tourer SE (traded in on a...),
> 1979 Fuji Royale II (sold to pay for a...),
> 1982 Trek 600 (which I rode for over a decade including
> a transcon tour before I crunched it under a car
> port and replaced it with a...),
> 1995 Trek 1220 (aluminum race frame which I finally
> got rid of when I found this on eBay...),
> 1979 Trek 510 (a bike that I just adore) and a
> 1983 Trek 311 (my errand bike).
>
> I'm particularly interested in pre 1984 Trek sport touring bikes. Some
> older pics of my 510 are here although please note that the components
> have
> been changed significantly (some new, some old) since these pictures were
> posted: http://www.vintage-trek.com/
>
> Lastly and perhaps most importantly, I'm very, very, very interested in
> older frame geometries and to that end I've been standing up a web
> projected
> devoted to compiling a list of bike geometries. My primary interest is to
> document older geometries from the 60s, 70s and 80s so that a) they aren't
> forgotten and b) that we might better understand the influence of these
> geometries and their relevance for today.
>
> If you post about an older bike of yours, I warn you ahead of time that I
> may e-mail you off list asking you to measure up the frame. Many of these
> bikes have geometries that are entirely undocumented. IMO, we're in
> danger
> of collectively forgetting so much.
>
> -Dave Mann, Boston, MA
> =========================
> =========================
> ================
> THE BIKE GEOMETRY PROJECT
> A community effort to document and compare bike geometries
> http://home.comcast.net/
> =========================
> =========================
> ================
> _______________________________________________
>
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