Brian,
Your and Doug's comments are what I was getting at - thanks for adding your thoughts.
It seems that when most frames had a 1" TT, it made less difference which method was used. It was easier to convert between the two because the variables were known. With various sized tubes used in current frame building - c-c dimensions seem to make more sense to me (and that's how I think about them) in that you could descibe 2 bikes with diffrenet size tubes but with the same geometry as the same size. Using c-t dimensioning - one would have to call these identical geometry bikes as different is size.
In architecture - those who design homes are used to the contractor oriented out-out dimensions of stud walls while commercial work uses c-c dimensions to lay out the variosly sized major structural elements on a grid. Traditional residential japanese architecture is one example where the c-c module rules and is very much like modern commercial construction in their approach - a result of a many centuries old tradition settling on a systematic approach that recognized the variables and dealt with them in a very consistent way.
Brian, when you think of a frame - do you think of the geometry in the same way as you size your bikes? Is your drawing of the frame start on a mark showing a c-t dimension (which would make sense in your case) - or is it just a sizing tradition you coninue in your work? Brian, I'm not saying your system should change - I think I have a sense of your traditional framebuilding approach and where your system came from.
Personally, I think for traditions to live and thrive - they need to recognize the chaging sea they swim in to stay relevent and so I think that traditions should evolve over time. We should also understand where they came from to know why they should or shouldn't change. That's what this little arcane subject was about.
Thanks again Brian and Doug and everyone else that has chimed in! I love hearing all thes points of view.
Roman Stankus
Atlanta, Ga. USA
> -----Original Message-----
> From: classicrendezvous-bounces@bikelist.org
> [mailto:classicrendezvous-bounces@bikelist.org] On Behalf Of
> brianbaylis@juno.com
> Sent: Sunday, February 11, 2007 12:22 AM
> To: fatticbicycles@qtm.net
> Cc: classicrendezvous@bikelist.org
> Subject: Re: [CR] Frame sizes/standards
>
>
> Doug,
>
> Good stuff! Regarding how Masis were measured; they were
> measured to the top tip of the point of the seat lug, which
> makes absolutely no sense at all. Most c-t measurements are
> from BB center to top of top tube. That's my preference. If
> someone wants a frame speced on a c-c dimension; I draw it
> that way, but when I stamp the frame size in the BB shell it
> will say 55.2cm, which is a 54cm c-c frame with a 1" TT. In
> this way the customer gets the "size" frame they understand
> or prefer but my sizing is consistently c-t in cm.
>
> Brian Baylis
> La Mesa, CA
>
> -- Doug Fattic <fatticbicycles@qtm.net> wrote:
> Roman Stankus asked:
>
> Here's a question that relates to framebuilding and history
> of the craft so I will beg forgiveness to cross-post to
> Framebuilders and CR list.
>
> Does anyone have any insight about using c-c vs c-t
> dimensions for seat tubes lengths when describing a frame
> size. It seems that most Italian builders used c-t
> dimensions. Was there a reason for this vs c-c dimensions?
> Did it have to do with the build process itself in some way?
> Did these methods of measure change over time for any reason.
> Are there any build traditions where the top tube is not
> measured c-c as is the norm now?
>
> Roman Stankus
> Atlanta, Georgia
> USA
>
> Hi Roman,
>
> I suppose I have some obligation to answer this question
> since it unfortunately dawned on me I might have probably
> been around good bikes longer than about anyone else on the
> framebuilder list (but not the CR list, whew). My dad got me
> my first 10 speed in 1963 and that was after having to wait a
> couple of years for it while we were in Rwanda and I went to high
>
> school in India. I got my first used Italian frame with
> Campy (gran spo rt
> derailleurs) parts in 1966.
>
> At that time in the states, everything I knew about was
> measured center to top in inches. And it fact we (as in
> American enthusiasts) tended to believe we needed bigger
> frames that what was necessary because of the dominance of
> Schwinn in the American market - particularly outside of th e
> biggest cities. Most likely somewhere on the list of
> bicycles owned wou ld be either a Schwinn Varsity,
> Continental or Super Sport. These were measured center to
> the very top of the seat tube (cut straight across) i n
> inches. Schwinn seat tubes stuck up quite a ways above the
> top tube so a collar with a bolt could be slipped over it to
> tighten the seat post (as is common today on tig welded
> frames). This made a Schwinn 22" frame actua lly smaller
> than one of the same size from Britain because it's top tube
> wou ld be lower down. I remember framebuilders in England in
> the 70's would complain to me all the time about Americans
> wanting frames that were too big for them. If a person's
> bike history included a Schwinn and he used that as a sizing
> guide, he was likely to ask for a frame 1" bigger than what
> he needed. It didn't help that those bikes were made in only
> even sizes.
>
> I've always thought that the way Masi frames were measured
> (c-t) was the
>
> exception for Italian frames and not the rule which was
> usually c-c. Br ian B. could say where that top point
> actually was/is. When I got a Masi in
>
> Italy in 1972, several letters in Italian (I used a
> translator) went bac k and forth about my measurements and
> Masi made me a 57cm frame. When tha t frame got stolen, I
> asked for a 58 and got one that size. Faliero stamp s the
> size on the bottom bracket shell. When I measured it, it was
> more l ike a 57cm c-t but I thought that was because he was
> stubborn and made me th e size he thought it should be anyway
> and put the size I wanted on it just to please me. It
> wasn't until I was on the CR list I discovered he measure d
> frames differently.
>
> One of the first questions I asked Jack Briggs when I was
> learning in England is where exactly is the Point where the
> "top' is. He thought th is British way didn't have a precise
> point. For example my 22 1/2" Hetchin s seemed a little
> small. Where Jack measured from is where the very top o f
> the top tube touches the seat tube. When I started building
> frames, I u sed a center to top measurement in inches as well
> because that was the syste m most customers understood. In
> my own records, I would record the center to center
> measurement. Sometime in the 80's in the states, the culture
> changed and customers started to expect their frame size to
> be given c-c in centimeters. I think this also reflected a
> change from Americans primar ily getting English frames like
> a Bob Jackson to Italian ones like Colnago.
>
> I will add that on many frames I've made, the controlling
> factor in determining frame size is it's top tube height.
> This is because of the need for some customers to get the
> handlebars up at a comfortable height compared to the seat.
> I will set the top tube at whatever height off the ground
> gives the right clearance. The result is odd c-c seat tube sizes.
>
> Doug Fattic
> Niles, Michigan