Hydration packs are a bit of an odd thing to try and review. In my experience, a hydration pack either holds water and has a tube that works, or it doesn’t. But cycling technology marches onward, so when the nice folk at Wheelies sent VeloBalls a Source Fuse Hydration Pack I decided to find out if the exciting world of bags of water has moved on since I last looked in on it.
Although I wouldn’t call myself a roadie at heart, I do spend most of my cycling hours on a road bike. Hydration packs are not considered appropriate for road cycling. Part of the reason could be the snobbery that we all claim doesn’t exist among road cyclists (see Rule #32), or it could just be for practical reasons. Either way, this is not the time to be figuring it out. Hydration backpacks are primarily used by mountain bikers, so that’s how we decided to conduct our tests; on a mountain bike.
Almost all of my mountain biking has been done near where I live in Suffolk (UK), which is a place entirely lacking in mountains. Hell, we haven’t even got any big hills around these parts. But as luck would have it my brother-in-law decided his stag do should involve a whole ton of mountain biking. Mountain biking on actual big hills. In Yorkshire. So early on Friday morning, I found myself hurtling (at a sensible speed of course) up the A1. Our destination was the Dales Bike Centre, which would be our home for the weekend. The weather forecast was predicting low temperatures, rain and snow. But hey, mountain biking can’t be all that tough, can it?
I have used a hydration backpack before. I haven’t worn one for cycling for several years, partly because off-roading is a rare thing for me, but mostly because my brother-in-law borrowed my old hydration backpack and I haven’t seen it for years. I wasn’t too bothered; my old pack never felt quite right when I wore it and had hardly any spare space once the bladder was full.
The Source Fuse Hydration Pack – a closer look
The first thing I noticed when I pickup up the backpack was how light it is. Granted the bulk of the ‘worn weight’ of any rucksack is a result of the amount of junk you cram into it, but the fact the bag was really light when empty was a good sign.
When you’re cold and your gloves are wet zips are near impossible to operate. You can easily find yourself stuck in a Catch-22 situation whereby you need to get into your bag to find dry gloves but can’t operate a fiddly zip because your hands are numb with cold. So the decent-sized loops attached to the zip pullers on the Source Fuse were a nice touch.
Because I was on a stag weekend I knew that we would be cycling with people who probably hadn’t ridden bikes since they were children. So I stuffed a whole lot of spare gloves, buffs etc in the hydropack for the inevitable moment when we found ourselves up on a hill and our friends were starting to suffer. I’m not the best man on this trip (there is no ‘best man’), so had no responsibilities but nobody likes to see friends suffer unnecessarily when cycling. So in summary I had to shove a whole lot of things in this backpack, and most importantly they had to stay dry. I was able to fit in everything I needed to with space to spare, and the shape of the bag didn’t change or bulge at all.
I was impressed at how well thought out the ‘storeganizer’ inside the bag was. There was a decent amount of separation between the compartments. There are even some pen pockets, although I’m not sure what use a pen will be if you’re freezing your ‘taters off on top of a snowy hill.
The importance of keeping the contents of the bag dry extended far beyond just needing to keep a few gloves and hats dry. I was also planning to use my hydration pack to store several video cameras, and they definitely need to stay dry. As if my camera equipment didn’t add enough jeopardy I was also carrying a lithium power pack. If you were paying attention in chemistry lessons in school you’ll know that getting anything with lithium in it wet is a really bad idea.
Before heading for the hills I tentatively ran the bag under a kitchen tap and was relieved to see that the water beaded off the surface perfectly. But the real test would be the heavy snow and rain we would be cycling in. The Source Fuse comes fitted with a painfully bright orange rain cover that is stowed in a compartment on the bottom of the bag. I’m not a fan of anything that covers the entire bag to keep it dry; because if you need to get to the contents of the bag quickly it’s just another obstacle. So I took the slightly cavalier decision not to use the rain cover.
So how well did this hydration pack actually perform?
The test ride for this backpack was nothing short of brutal. We cycled up and down the hills of the Yorkshire Dales in thick blizzards. After just 6.6 miles the group was given the option to quit and head for the pub. On a road bike in good weather conditions, a ride of six miles isn’t really a ride at all. Hell, on a road bike six miles doesn’t even count as a warm up. But on this day the howling wind, penetrating rain and befuddling thick snowfall were more than most of us could handle. On a typical ride in Suffolk, my Garmin might register an elevation gain of around 500ft. In just 6.6 miles in the Dales our elevation gain was a whopping 1,352ft! I realise our Northern readers will likely scoff at this, and quite right too! But with numb heads and hands, some of us conceded defeat.
While I was nursing a hot cuppa in the pub I realised I had been so consumed with just trying to stay upright on my bike I hadn’t made any mental notes about how well the bag I was supposed to be testing had performed. I tentatively opened the bag to check the contents. Everything in the bag was still bone dry. I was riding with a Garmin Virb Elite fixed to my helmet and the extreme weather had played havoc with it. So finding my other cameras and bits of clothing dry was a glorious surprise.

Before we had set off I couldn’t quite figure out how to stow the feed tube for the hydropack bladder, so I left it hanging loose. It never once got in my way and was easy enough to get hold of and shove in my gob when I needed it, which was often. The teat on the end of the tube was ‘switched on’ by rotation. I left it on for most of the ride and it didn’t leak. Water came out when I wanted it to and stayed in the bag when I wanted it to. In order to get water out of my previous hydration backpack required a fair amount of biting on the valve, but the system used on the Source Fuse was much easier to use.


The removable bladder in the Source Fuse was the best I’ve ever used. Even when full it didn’t make the bag uncomfortable and a decent layer of insulation between the bladder and the back of the rucksack meant the water didn’t make me cold. Other bladders I have used were filled via a screw cap and a small hole, meaning that drying the bag after use (very important) was near enough impossible. The whole of the top of the bladder in the Source Fuse opens for filling and emptying, making emptying and drying really easy. Once filled the bag is sealed via a sliding clip that snaps into place and feels reassuringly solid.
I wanted to draw attention to how easy it is to completely dry out the bladder because it’s really important. If you can’t properly dry out the inside of a hydration pack bladder after use it can foul quite badly. At the very least everything you drink from the bag in the future will taste grim. At the worst, if the bladder can’t fully dry it will develop mould, which is potentially hazardous to your health.
Source Fuse Hydration Pack – Conclusion
I think the best conclusion I can give regarding this hydropack is that I didn’t really get any strong impressions from using it. The water stayed where it should. The water didn’t taste like it had come from a swimming pool. The waterproof fabric kept my gear dry in challenging conditions. The pack was comfortable enough that it didn’t trouble me – I could concentrate on the ride.
Ultimately I don’t want any rucksack I wear to make its presence felt in any way. Most of the time I was cycling I almost managed to forget I was wearing a hydration pack at all.
So in conclusion, if you’re in the market for a hydration pack I can cheerfully recommend getting yourself a Source Fuse from the nice folk at Wheelies.
Find out more about the Source Fuse at Wheelies….
Last Updated on April 29, 2023
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