I have a set of 700D rims. Wondering if they should go into the scrap aluminum pile or if they were worth keeping, I tried to find a suitable tire to fit. I was able to install 26" x 1 3/8" (ISO 590, standard three speed size) tires, which I inflated to 100+ PSI and left for a week. No blow-off! Since the difference in bead diameter is 3mm, I wonder if going the other was is OK?
this is only my experience and I would never suggest or imply that this is a safe solution. The combination was only static tested, not ridden. Please consider this information of no actual, only anecdotal value. (Like my disclaimer?)
> I just received an early 70's LeJeune tandem I
\r?\n> bought on eBay, mostly
\r?\n> undamaged despite the worst packing job I've seen in
\r?\n> a while. The
\r?\n> seller didn't know a lot about it and said the
\r?\n> wheels were 24", which,
\r?\n> as I suspected, was not accurate. The bike has
\r?\n> Japanese rims (Arraya I
\r?\n> think) and the tires are marked "700D x 1.40".
\r?\n> According to Sheldon's
\r?\n> web site, 700D was 587mm and used only on a few GT
\r?\n> brand bikes.
\r?\n> Sheldon's site says French tandems typically had
\r?\n> 650B or 584mm wheels.
\r?\n> I can't find a size on the rims, but they are laced
\r?\n> to what look like
\r?\n> original Campy Tipo hubs and the rims themselves
\r?\n> look like 70's style
\r?\n> Arrayas, when this brand first appear in the US and
\r?\n> Europe. Could the
\r?\n> previous owner have gotten away with 700D tires on
\r?\n> 650B rims? (If the
\r?\n> seller installed these tires, he could easily have
\r?\n> put the wrong ones on
\r?\n> as he was calling these 24"). Someone have a good
\r?\n> method of measuring
\r?\n> rim bead diameter that will differentiate between a
\r?\n> 584mm and 587mm?
\r?\n> Jerry Moos