HydraPak UltraFlask Speed (500ml or 600ml) - Collapsible Soft Flask Water Bottle for Hydration Vests and Running Packs with Easy Open Cap

It’s solid and the best ones on the market. I have zero idea how I can even complain about it but it does exactly as advertised and don’t notice anything wrong with them. Bought them for my outdoor vitals skyline 30 since I lost one due to tsa. But for what it is I love them. I don’t have any leaks, stores flawless in several running vest I own and two different backpacks, it’s easy to carry and no funky taste and they are easy to clean so I don’t mind putting in some tablets in them even if trailrunning a two day trip. Plus I love the straws so it’s right by my face so I don’t even need to reach and drink instead I just turn my head and bite the valve and drink. It’s just all around a good design

These UltraFlask Speed bottles are excellent for trail running and longer training sessions. They fit perfectly into most running vest pockets, and the soft design means they conform to your body without bouncing or poking like traditional hard bottles. The bite valve works smoothly with a good flow rate, and the extended straw makes it easy to sip without removing the bottle from the vest — great when you don’t want to break stride. I also appreciate that the straw can be removed if you prefer a lower profile setup. As you drink, the bottle compresses to reduce sloshing and becomes lighter, which is especially helpful later into a run. They’re also simple to clean and dry, and the wide opening makes adding ice or electrolytes easy. Durable, lightweight, and very comfortable to carry — highly recommended for anyone running with a hydration vest or needing compact hydration on the go.

Great addition to son's collection and they were used in the cocodona 250. Perfect size, sturdy product and worked well for the race.

These soft flasks have become my goto hydration setup for long distance trail running. I love the size, the ability to pop the bottle open without unscrewing the top, and the bite valve. I think they are the best hydration option I've used. But they aren't 100% perfect. The bite valves seem to hold onto liquid, so you really need to pull the entire hard plastic piece out of the bite valve to wash it. Otherwise, even after a thorough cleaning, you'll still have just a bit of liquid hydration stuck in there. Even that is not too bad, but the hard plastic piece doesn't really nest into the bite valve when you put it back in. I'm always worried that will result in leaking. Along the same lines, some of the Hydrapak bite values lock into place, and some doesn't. (I don't use the extenders; they are too tall for me.) This one does not. So one time out on the trail, as I was drinking, the entire valve popped off, wasting a decent amount of liquid and getting my shorts wet. Not ideal, and it could actually be dangerous to lose liquid in certain situations. But if you keep that possibility in mind, the valve does stay on pretty much all the time. It's not a failure by any means. I'm glad Hydrapak are taking the low hanging fruit for hydration flasks. I just hope they make a couple of other changes to make it a perfect bottle.

One race in, and I'm in love. I have that common salomon vest, and had to replace the hydrapaks. These are bigger than what I had but still fit. Running with the straws was a mixed bag - I'm still working on the best way to keep them from bouncing around while also not being pressured to my neck. The access for a quick drinky drink was amazing. These also feel thicker than the Salomon version that came with my vest. These are worth the upgrade - though, I haven't tried other brands for a true comparison.

I’ve used the bottles on all of my long distance runs with no problem, including my ultras, 50k, 50miles, 100miles with no issues! Easy to clean dry & use on the go!

I bought this to help identify my electrolyte flask from my water flask during a long run and it's great! You have to press down firmly to make sure the lid is locked on, but once you do it doesn't leak and stays put! It's roughly the same size as the flasks that came with my hydration vest, so I can keep track of my hydration levels easily. When not in use, I can roll it up for easy storage.

I have been using HydraPak bottles for over a decade. The bottles used to be made out of pvc type materials, lids had a gasket that if not mindful of you could loose. After a couple years of regular use the seam would eventually spring a leak and the bottle was done. Honestly they function well and NEVER tasted funky. These new silicone or whatever they are taste beyond horrible, the flip cap is a pain and the way the cap is threaded, the hinge is always pushed into you. The worst is the stupid hinge wears a hole in whatever you’re using it with. I use Bottle Bright cleaning tablets regularly, wash after every use and use filtered water…..this is not a product of operator error. I love the collapsible bottles but will explore different brands.

Ich nutze die Flasks bei Trailrunning Wettkämpfen, bei denen es an den Verpflegungsstellen schnell gehen muss. Durch den Clip-Verschluss fällt das auf und zu schrauben weg und ermöglicht dadurch ein deutlich schnelleres nachfüllen. Die Flasche hält dicht und läuft auch in einem Laufrucksack nicht aus. Die Flasks haben ähnliche Maße wie die Salomon Flasks und passen in alle Salomon Rucksäcke, andere Laufrucksäcke weiß ich nicht genau. Natürlich ist die Flask nicht nur für schnelle/ambitionierte Läufer geeignet sondern auch für Leute die es gerne einfach haben. Jedoch würde ich schon sagen, dass der Hauptvorteil beim schnellen nachfüllen liegt.

Great for long runs. Doesn't leak and super easy to refill

I had an inov8 vest and somehow lost the part of the hydration pack that goes in your mouth. I think it’s called the bite. These are a perfect replacement and what inov8 uses. Only thing is they are a different colour and cost a lot if your just after the mouth piece

Use it in the shoulder pouches of an Atompacks 55 liter pack. Easy hydration on the move without having to pause to reach back for a bottle in a side pocket, which ensures constant and consistent replenishing of fluids. Large opening works well for pouring electrolyte powders. Simple to refill with a BeFree water filter. Recommend for simplicity on the trail.

Os flasks são de muito boa qualidade. Já os usei em treino e competição. A abertura rápida dá jeito para abastecimentos e agora uso sempre os extensores porque me dá mais jeito.