Working fine on flat roads

Involvement:Expert (understands the inner workings) - Ownership:1 week to 1 month

Very cheap, easy to use, fits any size of water-bottle.

Half-litre bottles don't fit as sturdy as 3/4 litre bottles. On a bumpy road full-bottles will quite easy jump out of the holder. Especially at high speeds like on a downhill, but also when going over a speed bump.

Material could have been a little stiffer, to prevent the bottles from jumping out.

Great value. Would suggest them for every bike you ride, except for the bike on which you're riding your races. On that bike you'll need a pair of holders which will hold the bottles when jumping at high speeds.