I would add a factor. Given the brazed in liner and straight cut treatment at the top, the seat lug looks very thick at the top of a Cinelli. So why file off a lot of lug to create a visual disparity?
That being said I went downstairs to look at a 1968 SC and the seat tube lug on this frame was the thinnest! And the upper head lug was thicker than the bottom! Reports please?
Joe Bender-Zanoni Great Notch, NJ
Mark Bulgier wrote:
>
> About Angel Garcia's Cinelli,
>
>>
>>
>>> http://www.wooljersey.com/
>>>
>>>
>
> I wondered:
>
>> Maybe the Cinelli-Cinelli seat lug was a casting?
>>
>
> A guy who should know for sure filled me in but doesn't want the credit.
> Back then all three lugs were sand castings - the thin sheetmetal lugs
> didn't come along until the mid-70s. In comparison to the smooth
> investment-cast lugs that came along still later, the earlier sand
> castings were rough, crude and thick, requiring a lot of work to make
> 'em look nice.
>
> So it looks like all 3 lugs on Angel's bike started out thick, and the
> head lugs just got more hand-filing than the seat lug.
>
> That makes sense in a way, because thinning the lugs extends the fatigue
> lifetime of the tubing by reducing the "stress riser" - the abrupt
> change in thickness right at the lug edge, from tube+lug to just the
> tube. And the tubes are far more likely to fatigue at the head lugs.
> Top tube cracking at the seat lug (where Angel's bike is thick) is
> fairly rare, so there's little need to thin that lug - other than
> aesthetics.
>
> Mark Bulgier
> Seattle WA USA