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Prime Thermal Bidon 500ml



Good all-rounder that keeps drinks cooler for longer but would benefit from minor refinement
Light yet solid
Easy to grip
Fits nicely in a jersey pocket
Good for small frames
Secure fit and easy release in most bottle cages
It only keep drinks cold, not warm
Domed cap would be welcome to protect spout

At every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.

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The Prime Thermal Bidon is a compact and lightweight bottle aimed at riders with smaller-framed bikes looking to save grams while keeping your drinks cool. On this basis, it does exactly what it says in the blurb and keeps drinks cooler for longer than some of its competitors. The 500ml size is also a good bet for smaller, compact geometry frames. However, a protective cap to prevent ingesting nasties thrown up by the front tyre would've been welcomed.


The bottle is made from BPA (Bisphenol)-free plastics, so shouldn't taint your tipple, or cause nasty chemicals to leach into you. Nothing particularly new there, but what's this nanogel, then...? Well, apparently, it's the world's lightest insulating material, made from 5% 'solid material' and 95% air, and it's reckoned to keep drinks cool for four hours.

Given most of us associate the word 'thermal' with heat or keeping a consistent temperature (whether hot or cold), the fact that the Prime Thermal is not designed to keep warm drinks warm might come as a shock. If you haven't clicked away having read that, this is a compact 500ml (about 16.91 oz) bottle, so should fit nicely in most jersey and jacket pockets. It's 74mm (about 2.91in) in diameter if you're wondering whether it will be a snug fit in your cages.

2022 Prime Thermal Bidon 500ml - nozzle.jpg

As for the spout, it's a simple push-pull affair, so should be intuitive. Prime makes weight a selling point, but at 116g it's heavier than some other bottles with thermal properties, including the Passport Frostbite Reflective Water Bottle, though it's lighter than the Elite Nanogelite.

Cage compatibility/Security

I've successfully paired ours with traditional and contemporary shapes, made from carbon, composites, stainless steel, aluminium alloys and titanium, which can be a little springy. Release across the board has been faff-free-grab, guzzle and slot back. 

More traditional cages with gripper buttons, the sort featured on the Elite Ciussi and this Van Nicholas Ti bottle cage, were arguably the more secure, vibration-damping hosts, although thankfully, I found reliability with side-entry models, including this Lezyne Flow SL similarly good on and beyond tarmac, which is good news if you ride a bike with a smaller frame

Smaller bottles are a less obtrusive fit in your jersey/gilet and jacket pockets and the Prime is no exception – helpful if you want some cooling relief on hot days or when you're grinding away on the indoor trainer. It's much the same story security-wise – no ejections or similar woes whether exploring green lanes, unmade roads or just hossing along washboard tarmac.

Grip, at least in gloves with leather palms or those dotted with silicone detailing, has been similarly reliable, although some non-cycling-specific, technical gloves made a less tenacious connection – not that I dropped the bottle, but I needed a firmer grasp.

Flow rate and thermal properties

Flow rate is predictable from the spout and the bottle is easy to compress for a quicker delivery. It becomes slicker with use and again, doesn't seem prone to unwanted dribbling, or leaking – I've parked the bottle upside down in a pocket and not had any issues, either.

Now, this would be an absolute boon if the thermal properties were a two-way street. Alas, while it has kept cold stuff chill for the claimed four hours – at least during November and December, when temperatures ranged between freezing and 12°C, the inability to fill it with something warming was a little disappointing – especially given its 'thermal' tag. Minor grumbling aside, drinks tasted authentic and crisp, with no chemical taint.


The neck is sensibly wide, so most bog-standard bottle brushes should get right into nooks and crannies, purging any stomach-upsetting bacteria. Gentle tickling rather than enthused scrubbing is key here, with no effect upon the bottle's technical properties to date. However, I would avoid powerful cleaners, such as Milton.


The Passport Frostbite Insulated Reflective Water Bottle is 550ml and costs £11.99. Made from PVC, the thermal properties are two-way, and George found it a good fit in his cages. As a side note, it also features retro-reflective detailing for some added night-time/winter presence. However, the bottle walls were less malleable, requiring more effort to get drinks to flow.

The Elite Ice Fly is available in a 650ml version for £11.99 and includes a protective cap to protect spout from getting caked in filth but only keeps drinks chill for two and a half hours


The Prime Thermal Bidon is a competent bottle and on the plus side, has done what it says in the blurb. It's a good bet for smaller frames, and stuffed in a jersey pocket, could supply some cooling relief on a very warm day. However, there are cheaper alternatives, and a protective cap would be a welcome touch whether you're riding on road or off.


Good all-rounder that keeps drinks cooler for longer but would benefit from minor refinement

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Make and model: Prime Thermal Bidon 500ml

Size tested: 500ml

Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?

Prime says: "Keeping your liquid cold for up to 4 hours, this 500ml thermal water bottle maintains a consistently cool temperature thanks to its nanogel construction. Known as the world's lightest insulating material, it's made of 5% solid material and 95% air. It features a BPA (Bisphenol-A) free certified plastic construction as well as nanogel, which is surprisingly lightweight. This makes it a major benefit for riders who want to shave important grams off their overall bike weight, without worrying about adding unnecessary water bottle weight. Due to its versatile construction, this model allows for high thermal capacity, extra lightness, and fantastic flexibility in a single product."

My feelings are that it's a competent bottle that is pleasant to use and straightforward to care for – but its thermal properties only refer to keeping stuff cool.

Tell us some more about the technical aspects of the product?

Material: Nanogel, BPA (Bisphenol-A) free certified Plastic materials

Size: 500ml

Thermal Effect: 4 hours

Valve: Push-pull

Diameter: 74mm

Safe and odourless

Innovative design

Weight: 109g

Rate the product for quality of construction:

Solid and easy to clean.

Rate the product for performance:

Pleasant enough to use, seems compatible with most standard bottle cages and is straightforward to care for. Keeps cold drinks cold, seemingly for the four hours cited.

Rate the product for durability:

Materials feel solid and coating unaffected by gentle brushing but difficult to say so far what it will be like in the long term.

Rate the product for weight (if applicable)

The 116g is heavier than the likes of Passport's Frostbite Reflective Water Bottle but lighter than others, including the Elite Nanogelite.

Rate the product for comfort (if applicable)

Easy to grip, decent flow rate and has kept contents cool for the stated period. Being 500ml, it is also less obtrusive in a jersey pocket, compared with more traditional bottles.

Rate the product for value:

Dearer but keeps contents cooler for longer than some competitors.

Tell us how the product performed overall when used for its designed purpose

Overall, the Prime Thermal Bidon is a competent bottle that is comfortable in a jersey pocket, easy to grasp, and a good fit for smaller/compact geometry frames. Genuinely keeps drinks cool for four hours, which is an improvement over some competitors, although thermal might imply it'll keep coffees, teas etc hot – but it doesn't. The use of BPA ensures drinks have tasted crisp and authentic, without any chemical taint. No less than I'd expected, but appreciated just the same.

Tell us what you particularly liked about the product

Nice to hold, a good fit with smaller/compact geometry frames and jersey/jacket pockets.

Tell us what you particularly disliked about the product

Nothing, given the design brief, although a protective cap would be welcome to keep spray and filth contaminating the spout.

How does the price compare to that of similar products in the market, including ones recently tested on

The Passport Frostbite Insulated Reflective Water Bottle is 550ml and £11.99. Made from PVC, the thermal properties are two-way, and George found it a good fit in his cages. As a side note, it also features retro-reflective detailing for some added night-time/winter presence. However, the bottle walls were less malleable, requiring more effort for you to get drinks to flow. The Elite Ice Fly is available in a 650ml version for £11.99 and includes a protective cap to protect spout from getting caked in filth but only keeps drinks cool for 2.5 hours

Did you enjoy using the product? Yes

Would you consider buying the product? Possibly

Would you recommend the product to a friend? Yes, particularly if they had a smaller, compact geometry frame.

Use this box to explain your overall score

A decent bottle that keeps cold drinks that way for several hours. It's also a nice size for smaller frames and jersey pockets.

Overall rating: 7/10

About the tester

Age: 49  Height: 1m 81cm  Weight: 70kg

I usually ride: Rough Stuff Tourer Based around 4130 Univega mtb Frameset  My best bike is: 1955 Holdsworth Road Path and several others including cross & traditional road

I've been riding for: Over 20 years  I ride: Most days  I would class myself as: Experienced

I regularly do the following types of riding: cyclo cross, commuting, touring, fixed/singlespeed, mtb,

Shaun Audane is a freelance writer/product tester with over twenty-eight years riding experience, the last twelve (120,000 miles) spent putting bikes and kit through their paces for a variety of publications. Previous generations of his family worked at manufacturing's sharp end, thus Shaun can weld, has a sound understanding of frame building practice and a preference for steel or titanium framesets.
Citing Richard Ballantine and an Au pair as his earliest cycling influences, he is presently writing a cycling book with particular focus upon women, families and disabled audiences (Having been a registered care manager and coached children at Herne Hill Velodrome in earlier careers)

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