First Look Review : Pete’s Pipedream Sirius S5.

The Pipedream Sirius S5 is designed as your do-it-all Cro-Mo trail hardtail that can take 29″ 27.5″+ wheels for whatever riding you do.

With a build at the downcountry or XXXC end of the spectrum, Pete has been putting the fifth generation of the Pipedream Sirius through its paces and has give his opening thoughts.

Photos and words by Pete Scullion.

Build and spec

While this review is about the frame-only offered Pipedream Sirius, it seems daft not to contextualise the ride experience by way of the build. Not being much of an ‘adventure’ rider in the modern use of the word, the build is at the more gravity-inspired end of the spectrum without killing any of the mile-swallowing capability that the Sirius is designed for.

Damping is dealt with by a Rockshox SID Select+. The SID line has come leaps and bounds as suspension has advanced and they feel far more burly than an XC fork should. I run them fast and firm on the Sirius to keep things lively.

Drivetrain is a Shimano XT affair running on a Deore crank, so I can expect shifts to be smooth and reliable throughout. Wheels are a set of Pacenti S1 wheels which are a fully unknown quantity to me, and they’re shod with 29 x 2.3″ Pirelli Scorpion Enduro S tyres front and rear.

RaceFace Atlas 35mm bar and stem handle the steering, with a Hope headset keeping things smooth. Dropper is a venerable Brand X Ascend number with a Charge saddle.

Brakes are Magura MT Trail Sport, with a 4-pot out front, with a 2-pot number on the rear. My previous experience with these brakes has been mixed. Power has been excellent, but keeping them running rub-free and trying to bleed them is nothing short of a nightmare. Hopefully these prove otherwise.


I opted for the smallest of the Sirius S5 frames, ‘Longish’, although I think I could bump to a ‘Long’ if I wanted to. You get a 445mm reach on the ‘Longish’, combined with a suitably short 395mm seat tube. Head angle is 65 degrees with a suitably steep 77.5 degree seat tube angle. 395mm chainstays produce a wheelbase of 1155-1171mm, using the sliding dropouts.

Opening moves

I haven’t ridden a hardtail since I fell back in love with steel and hardtails thanks to the Ragley BigWig I tested last year. Knowing that this would be a very different beast altogether, I set about recalibrating my riding to suit, and cracked on.

Almost immediately, the Maguras made their presence felt. Mildly warped rotors and very little float meant getting them centred was… fun. Thankfully, these would stay put once I got them lined up amidst a flurry of profanities, and I could focus on the rest of the bike.

After a few very steady runs on easy trails to reassess whether or not I can ride hardtails, it was time to up the ante. The old adage, the faster you go the easier it is seemed to ring true with the Sirius, and keeping the front wheel up definitely seemed to help smooth things out.

Finding the balance point on the rear wheel to that end was easy, the 395mm chainstays giving the Sirius a very playful feel compared to some of the behemoth chainstays I have witnessed of late. A visit to the Velosolutions pumptrack at Cathkin Braes felt very sensible on the Sirius, after coming alive on the jump line. A very different experience to the Aberfoyle slickness. It handled both admirably, I might add.

As the speed picked up, the rather stiff 35mm cockpit started to feel a little less pleasant on the hands. My previous experience with carbon RaceFace 35mm kit on the Cube Stereo 140 is that it is stiff, and that’s no different here with the Atlas numbers.

While I don’t have too many steel hardtails to compare it to, the Sirius seems to lack the twang I most definitely felt in the BigWig when really starting to push it, and it did help take the edge of the ride. Maybe I just haven’t tuned myself into the Sirius’ twang frequency, but on the whole it feels like a stiff rocketship of a hardtail, that puts the power you offer to the pedals into the rubber on the dirt.

So far, the Sirius has done everything I have asked of it, and stiff doesn’t always mean negative. It’s pushing me to thing about where I put the bike while I ride it, rather than just pointing and shooting. Overall bike weight is low, and I feel centred on the bike, so shifting the weight about feels easy, and getting it off the ground is comically easy.

I’m looking forward to spending more time on the Sirius as it’s definitely a riot, at the moment, it’s a bit too much football hooligan riot for me, but that’s likely due to my lack of time on hardtails and just trying to ride all the mad stuff I’d ride on a bike with two suspended wheels. I’m sure it’ll become more peaceful protest soon.

You can check out the Pipedream Sirius S5 on the Pipedream website here.