The Absolute Speed BTS: Sturdy, Safe and Secure 

The Slowtwitch Kona bike count always reveals something new and, as we reported, rear hydration systems saw a sizable shift this year. The development of aerodynamics and nutrition practices has brought new behind the saddle (BTS) products to market and Kona was the perfect runway for us to see what’s what. 

New Look, Same Solution

Rear hydration mounts have been around for a while, but their development plateaued after their commercial launch. It was Scott Tinley chasing his second world championship title in 1985 who first rigged his bottles behind the saddle in an effort to reduce drag. The DIY solution was all triathletes had until X-Lab debuted a dual-bottle rear mount in 1993. Their “Saddle Wing” was the first commercial BTS product on the market, and you can still buy an iteration of it today. More companies came to the party, most notably Profile Design, and the tech progressed to offer better bottle security, adjustability, easier mounting and lighter carbon options. But rear hydration remained an afterthought. 

No Longer an Afterthought 

Today, advances in aerodynamics and nutrition, along with the growing importance of both to remain competitive, have pushed rear hydration beyond its stable and lacklustre progression. 

We can separate rear hydration into two categories: integrated and aftermarket. Many bike manufacturers are integrating rear hydration (and front/BTS) into their overall TT bike design. The Canyon Speedmax and Quintana Roo V-PRi both come to mind. Aftermarket products promise the same aerodynamic advantages with both custom 3D-printed options and mass market options available. In Kona, the EZ Gains Hydro Gains was seen on a majority of pro bikes and represented 22.66% of athletes overall. Integrated systems were next on the list, followed by X-Lab and Profile Design (you can see our data here). As we noted, however, almost 15% of BTS hydration came from “other” brands. 

Absolute Speed

Absolute Speed was one of those “other” brands at Kona. Matt Hanson, Kieran Lindars, Daisy Davies and Cameron Main used both front and rear hydration systems from Absolute Speed at the world championship. Their flagship product is their BTA system, but early this year, their BTS started to appear on the bikes of their sponsored pros. 

What initially caught our eye back in May was the system allowed bottles to point forwards. It seems like everyone made the switch to forward-facing bottles this year but it was a small detail that felt like one of those: “why haven’t we been doing this the whole time?” Who hasn’t struggled to get a rear-facing bottle out or back into its cage, even during training, let alone in a race. 

The overall BTS design is in line with other “fin-style” options on the market. It comes with a saddle-specific or universal mount, an optional spacer, and an optional two-bottle adapter. The full three-piece setup, which is how we tested them, weighs 300g (200g for the primary mount, 50g for the spacer, 50g for the adapter, and that doesn’t include bottle cages or bottles). By comparison, EZ Gains lists their mount as 250g, but its system also comes with a warning to only use up to 1.5L (2x750ml bottles maximum), whereas Absolute Speed does not list any bottle weight limitations. 

The Absolute Speed also offers angle adjustment so you can position the mount to suit your set up. It also comes with a five year warranty and a 90-day trial period. The three-piece bundle (without cages or bottles, which are optional add-ons) retails for £250 (US$333) which seems to be the going rate. 

Absolute Speed BTS Test

Over the past few months, I’ve been riding with the Absolute Speed BTS. I haven’t been able to race with it, but I’ve done several long, difficult training sessions, including a 160km TT ride with long race-pace blocks. But, let’s start at the beginning. 

The Absolute Speed BTS comes with all the necessary bolts, and mounting is straightforward. It took a little adjustment to get the adapter into the right position so the bottles weren’t over the saddle, but that’s my lack of mechanical skills. It was on and ready to ride pretty quickly. 

The mount felt heavier than expected, but also sturdy. I opted for the two-bottle set up and typically used two 750ml bottles. The mount seems optimized for 500ml or 750ml bottles. The big 1L bottles that I tend to use for long, unsupported training rides do fit but, because I chose to position the bottles forward, they hit my bum on the saddle and I couldn’t adjust the mount bar to avoid this. I can still ride in aero and sit up without them interfering, but, especially when sitting up, I can feel them and they are “there.” That would be easily solved by turning the bottle cages around for a more traditional rear-facing setup–but I quite liked having forward-facing bottles. 

Forward-Facing Bottles 

I noticed in Kona that forward-facing bottles were definitely the preferred choice of most pros, but of the pros using the Absolute Speed BTS, it was only Davies and Lindars (who first used the Absolute Speed BTS with forward facing bottles at Ironman Texas this year where he set the British Ironman bike record with a time of 3:58:11). I found it was easier to pull bottles out straight rather than reaching all the way back and pulling them out at an awkward angle. I’ve actually had a lat cramp during a race trying to get rear bottles out before and, while the awkward movement is just something we’ve all had to get used to, a smoother, easier movement is faster. However, at first, getting the bottles out was impossible. 

The cages they sent with the mount were obviously new and very tight. On my first test ride, I actually had to stop and use two hands to get a bottle out. For the next ride, I swapped out my bottles for softer, older ones, and then it became easy. If that didn’t work, I had planned to switch out the cages for a different style, or just an older one that was a bit more relaxed and worn in. That might be an issue in a race if the bottles are stiff and a tad bigger, but this is a cage issue, not a mount issue. So, if I were buying now, I would source my own bottles and cages. 

An added bonus was there was no need for safety elastics. If a bottle started to slip out, I would feel it and be able to nudge it back in without leaving aero or skipping a pedal stroke. But, I have to say, this only happened twice with an empty bottle over the course of three months, and part of that was the sturdiness of the mount.  

Sturdy and Secure

What impressed me the most was how robust and secure the Absolute Speed BTS mount was on even the most bumpy roads. Not only did my bottles stay in place without elastics, but they always felt secure. The BTS mount handled the weight of my bottles (even 2 x 1L) without feeling like the system was overburdened. There were no vibrations coming through and at no point did I feel like I had to check on my bottles, or the mount, after a particularly jarring bump in the road. It felt like it was integrated with the bike, not an attachment. 

Aerodynamics wise, all I have to go on is feel and eyeball. But, if conventional wisdom and the setups of wind-tunnel-tested pros can be trusted, it was easy to get my bottles close to my body and at the correct height. 

A Safe Bet

Since my Cervelo P5 doesn’t offer an integrated system, the Absolute Speed BTS is a great aftermarket addition to my setup. It’s everything it needs to be and nothing more which, in my mind, is exactly what you want when looking for a BTS system. I had full confidence in the security of my nutrition, the mount handled the weight and every bump, and, most importantly, it became easy to use. 

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