I would have returned them except they are less than the return shipping price. I was able to shove them in the tire by doubling them over for a few inches but it was a lumpy ride and I found an actual 20 tube at a local bike shop.
I am not actually sure what size they are but not the 20 advertised.
I dumped the French vale and milled the hole in the rim a little bit to take the Schrader (American valve stem which has not given me any trouble and the performance of the trike was improved. and the ride was more comfortable especially on the rural bumpy death road I have to ride on! In the first week I got my new Cattrike I had replaced One expensive racing tire and tube in the other two wheels. I have had the tubes and the slime in use for about 2-3 months and I usually ride 30 miles at a time-with a 24 speed lightweight bike it isn't that big of deal. I have only the wonderful trike to get around as some of my disabilities prevent me from driving-so reliability is a major issue. The trike is the Cattrike villager (MSRP $2595) and it is so light that mid breeze can propel the thing if I don't secure the wheel. It most powder coated aircraft aluminum and when you hit 45 mph (going down a very steep and long hill the trike tends to lift off all three wheels. So I don't know whether to install wings on it or some kind of spoiler to keep it on the ground. I am a 63 year old retired air force pilot and while being completely in the air going down those hills-it felt good. AND NO Tire ISSUES.
I have 3 old Schwinn's, a Speedster, Breeze, & a Collegiate. All use the same tires & tubes for the Schwinn S-6 rims. The Kenda tires & tubes have been good. My only issue is that after a couple of years of service the glue or whatever seems to let go on the valve stem & you will feel a small blister or bubble on the lower valve stem, it will blow out. This has happened twice to me in the last year. Fortunately I was home when they blew, & not ten miles away from home.
Tubes today are porous & Iose 5-10lbs. of air per week. Now when I air up the tire weekly, I check the valve stems for the bubble. I rode 900 miles this summer 2015
I am a small bike repair shop. I buy and repair used bikes and sell them. I also repair customer bikes, Sometimes they are old classic bikes, sometimes they are top of the line new style bikes and I need parts and tires for all styles.
used these tubes as a general purpose tube with a presta type stem. used on a catrike with schwallabe marrathon plus tire. i did notice the plus tire added a noticeable drag to the bike trip, but no leaks
one of the two tubes purchased burst on when inflated first time
First tube worked great and no flats for an entire year. This year I ran over a goat head so I had to finally change a tire. Next two tubes had issues out of the box. First one had a weak wall and had a huge bulge in the tube. Second tube had a defective valve that I didn't notice till it went flat again. Hopefully this third tube will last a little longer until I get my next shipment of new tubes!
Over 35 years I have installed hundreds of tubes on family and friends bikes. It seems the tubes of late are getting worse. I don't know what the composition of rubber is but I am ever finding patches won't stick to this crap.
As cyclists we should demand at least a tube that holds air when installed. I use tuffy liners for most installs and don't feel the need for the higher priced tubes. But at the very least, I want them to hold air for the initial filling.