The hoop diameter is of no concern, but there is Mark's concern in getting a fatter tube inside of a 19mm tire. If one is careful, a bigger tube can be fitted in a narrow tire without any folds.
For comparisons, I measure most "road" tubes in their flatted state, layed flat, at 22-24mm wide. These fit 20mm tires just fine, and I've put wider tubes into 23mm tires, tubes which measure 28mm wide flatted and which are labeled for 28-32mm tires.
Torrelli tubes have come in at a consistent 22mm (flat width) and hold their round shape with less air in them since their folded shape somehow doesn't take a set. They would seem to be the easiest to install.
There is additional air volume in the rim cavity which allows larger tubes to fit within relatively small tires, but as always, technique rules and it is often necessary to release air as the tire is being installed. Fatter (oversized relative to stated tire size) tubes stretch less to fill the tire's volume, and so punctures lose air at a much slower rate, often allowing me to ride home before making a repair.
David Snyder Auburn, CA usa
From: "Steve Birmingham" <sbirmingham@mindspring.com>
> I'd try a set of inexpensive 700c tubes. Many of the less expensive brands
> are labeled
> with both 27 and 700c dimensions, like 700x18-23 27x1. This size should
> fit
> 27x7/8 pretty well.
> I think they split the difference on diameter, and the rubber is stretchy
> enough that it works just fine.
> And if you don't like the fit you can always use them on something else.
>
>
>> From: Mark Chance <mcjjj1@comcast.net>
>
>> Speaking of clinchers
>>
> Speaking of clinchers, where can I find a set of tubes that will fit my
> 27x
>> 7/8 Clements? My LBS thought I was out of my mind when I asked them
>> yesterday. If you know of good source that stocks tubes the size of
>> spaghetti noodles, please let me know