At 12:34 PM -0800 1/9/08, Jerome & Elizabeth Moos wrote:
>What size tubes are needed for 650B tires? Has Rivendell made 650B
>popular enough again that tubes are made specifically for this size?
>If not, 650A/ 26x1 3/8 at 590mm would be closer to the 650B 584mm
>than would 650C at 571mm. In fact 650A and 650B are a bit closer
>than 27" and 700C, which use the same tubes. However, I believe
>650A, at least in recent decades, was used mostly 3 Speed bikes, so
>available tubes may be pretty wide, whereas the newer 650B tires can
>be as narrow as 32 mm. What is the experience of you 650B users out
>there?
The "650B specific" tubes exist. Vintage Bicycle Press stocks very nice Schwalbe tubes, which are specific to a number of 650B and 650A, as well as 26" x 47 mm. (It says so on the box!)
Unfortunately, we have a $ 25 minimum order, so they are available only with a tire purchase.
I have used these tubes with everything from 29 mm Michelin Megamiums to 42 mm wide Grand Bois Hetres. They worked well in all of them, with no difficulty getting them into the tubes. Rubber stretches... (I use Michelin 23 mm tubes in my 700C x 30 mm tires, without problem as well.)
I tried 26" latex tubes, and while they ride nicely, they were a chore to install, because latex holds its size nicely, and 559 mm is a bit different from 584 mm.
Jan Heine
Editor
Bicycle Quarterly
140 Lakeside Ave #C
Seattle WA 98122
http://www.bikequarterly.com