After ordering these tubes I did lots of reading about how lightweight race tubes are horribly unreliable & require daily inflation. Nothing could be more untrue about these contis I got them as a set with Ultra Sport II Folding tires & I ride every day. The rim has bottoms out sometimes twice a day, and I dread a pinch flat each time it happens, but so far the tubes have held up lovely. I've begun stocking up on tubes & conti tires bc I think they have the best product & reputation in the sector.
Been using this tube for years mostly with Vittoria Rubino Pro's with a fairly high PSI (110-120). I get pretty good milage out of these on my road bike, commuter bike, and track bike.
The Continental Race Light Road tube is a fantastic tube and at BikeTiresDirect they are a very reasonable price. The Continental tubes are well made and long lasting for light weight tubes. Multiple rolling resistance tests show that the lightweight butyl tubes are within 2-3 watts as latex, but a lot less expensive. And, butyl tubes are safer to use in carbon clinchers due to their higher heat tolerance. The pressure loss of the Continental Race Light tubes is much better than any latex tube. The Continental Race Light tubes offer a great option for fast riding when the limitations of latex aren't worth the benefits.
I got these this year since I've started racing as well as doing more high climb centuries (9000 - 11,000 ft) to save weight. However, I'm switching back to Tour 700s because I've been having so many pinch flats during training rides. The rural roads around here have plenty of potholes, rocks, debris, etc. and I got stranded 50 miles from home yesterday with two pinch flats (one on my rear tire and then another on my spare).
Have used these Continental Race light tubes in 700x25 (Michelin) racing and training tires for several years. No problems. Stems work well with screw-on, shop and bike-mounted, pumps (Lezyne.) Sometimes I deflate slightly after ride, sometimes I just leave them at 110 psi. Doesn't seem to make any difference. (Although I still feel, from the old sew-days, that stretched rubber should be allowed to rest after a ride.) I would give it 5-stars except can't see calling any plain-ol' bike tube awesome and a steal. ,-