The GTs were introduced in 1980, and were apparently not particularly popular (as one would expect from the "last of a line" product), though those who have them installed on their bikes like them very much. The quick release mechanism appears to work best with tires no greater than about 30mm in width. The reach is only slightly less than that of Mafac Racers. They have brass bushings, are as "smooth as silk," are reported to have little squeal.
To my eye, they are also very beautiful -- more sculpted and polished than any other Mafacs, as Jan Heine writes in the current BQ, where there are some nice photos of the brakes, which also show how the QR works.
I don't see any on eBay at the moment, and I don't get a sense of there being a tremendous amount of them out there. But I also don't know how valued they are by collectors. I certainly like them very much. Do please let me know if you know where I could find some.
Adam Hammond Toronto, ON, Canada
On 4-Dec-07, at 11:40 AM, Kurt Sperry wrote:
> Thanks to the replies being off-list (do people who reply to questions
> off-list ever stop to consider that they are by doing so impeding the
> spread of useful information on our hobby?), the question reemains
> unanswered. Care to share what those replies were?
>
> Kurt Sperry
> Bellingham WA
> USA
>
> On Dec 4, 2007 7:10 AM, Adam Hammond <anhammond@gmail.com> wrote:
>> I'm sufficiently convinced by the off-list replies! If anyone has a
>> NOS or excellent set of GTs, please let me know.
>>
>> Thanks,
>>
>> Adam Hammond
>> Toronto, Ontario, Canada