You're right, of course, Sheldon. Please read "700D" for "650D" in my post. Otherwise, I think it is accurate. GT seems to have totally made up the "700D" designation, so they could just as easily have called it "650D" I suppose. As the result of responses and further examination of Sutherland's, I've concluded that these are 700D rims and plan to replace them with original-sized 650B. This may prevent me from bringing the bike to Cirque as I had hoped. Apparently some misguided soul thought the GT 700D was the wave of the future and replaced the rims sometime in the 80's, either because he didn't know where to get 650B tires or because an original rim was damaged.
Regards,
Jerry Moos
Sheldon Brown wrote:
> Jerry & Liz Moos wrote:
> >My recently purchased early 70's Lejeune tandem came with original Campy
> >Tipo hubs laced to what I thought were Araya 650B rims, but with the
> >oddball 650D (xx-587) tires made only by/for GT.
>
> Jerry, there's no sucha thing as "650D". The GT oddball 587 mm size
> was designated (by GT) "700D"
>
> > As 650D wheels could
> >not possibly have been original, I figured someone had substituted
> >incorrect 650D tires for the proper 650B (xx-584), but got away with it
> >because the difference is only 3mm. I purchased some 650B Michelin
> >World Tour tires and installed one today. It went on, but only with
> >great effort. The rim is marked Araya RM-20, but has no size markings.
> >I measure it about 570mm inside diameter and about 597mm OD to the tops
> >of the flanges, but I don't think I can measure a built-up rim closely
> >enough to tell the 3mm difference between 650B and 650D.
>
> Sure sounds like a 700D to me.
>
> >I see no point trying to find spare
> >650D tires, and if I conclude the rims are 650D, will rebuild with 650B,
> >both because that is original and because 650D tires are essentially
> >impossible to find. Anyone have some different advise?
>
> Nope.
>
> >Meanwhile,
> >anyone see any reason other than difficult tire changes that I shouldn't
> >use the 650B Michelins on the possible 650D rims?
>
> Nope.
>
> Sheldon "Not A GT Fan" Brown
> Newtonville, Massachusetts
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