Tested : Pete’s Pipedream Sirius S5 Review.

A month or two in the mud of central Scotland should be a suitable test for Pipedream’s trail hardtail, the all-steel Sirius S5.

Less hardcore than the Moxie, and less all-road than the Alice, the Sirius S5 is made for pretty much anything other than steep, spicy trails. Pete has spent the darker months finding the measure of the Sirius.

Photos by Pete Scullion.

Key features:

  • Frame-only (includes sliders, bolts and guides)
  • 29er, 27.5+, 27.5 or ‘mullet’.
  • 100-120mm 29er fork.
  • 120-140mm 27.5 fork.
  • Custom butted, heat treated CrMo 4130
  • 44mm head tube (fits all steerer tubes).
  • Sliding dropouts give +16mm of chainstay length adjustment.
  • Includes Boost™ axle.
  • £699.00 RRP
  • PipedreamCycles.com

While far racier than the Ragley BigWig I tested a few years back, the Sirius certainly isn’t a race bike by any means. Show it anything between a good old fashioned cross country ride and some quality singletrack and it’ll be a faithful companion throughout.

What you might not get from the Sirius is that classic steel twang. The BigWig certainly felt comfy on the big hits and square edges, as far as a hardtail could, and while there wasn’t a massive deal between them, the Sirius feels more taught and nudges you to pick a smoother line.

With frame-only currently the only option available, custom builds on the Sirius can be very different to the one seen here. With a 120mm 29″ SID, the Sirius feels fast across the ground and can deal with some nonsense on the downs, while a 140mm 27.5″ fork might have it dealing with spicier downs, with maybe a trade-off in mile-munching capability.

This Sirius came with a Rockshox SID Select, Pacenti wheels, Pirelli Scorpion tyres, Shimano Deore/XT 12-speed, a Brand X Ascend dropper and a 35mm Raceface cockpit. Brakes are Magura’s MT Trails Sport. On the speedy side with a solid nod to having fun on the way down.


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.

Over the last month or two, the Pipedream Sirius S5 has been everywhere with me. From big, easy miles to skidding about the woods, it’s been a very capable companion that will do pretty much everything you ask of it. At the stiffer end of the steel spectrum, it makes more of the energy you put into it, and can feel unforgiving it you treat it rough but is swift across the ground if you pick the right line.

If you want something that can do more than cross country and less than enduro, the Sirius S5 is a bike that can bridge that fairly massive gap. The build spec on this bike reflected its broad capabilities and helped eek the best from it in all situations.

Arguably the best thing any bike product can do is simply operate as intended without complaint, and that’s exactly what the Sirius did. Despite its trail credentials, I found the Sirius incredibly easy to manual, and I found myself practicing wheelies on the Sirius more than any bike I have ridden for quite a while. As a result, I left the sliding dropouts in the shorter configuration.

On the ups, I never felt that the fairly steep seat tube angle had me hovering too far forward. The rear felt taught and delivered any power you offered up into the rear wheel without complaint. The only weak point was the Pirelli rubber that, in its defence, was a fairly front tyre specific model.

When things turned downhill, the Sirius preferred a slightly more measured approach, certainly when things started getting interesting. You’d know soon enough if you weren’t riding well, as you’d feel a the full force of any kick to the back wheel in the soles of your feet.

Pick a line, use the roomy cockpit and short chainstays to keep the front wheel up though and the bike would fly. I could have opted for a Long to get more cockpit room for some additional rowdiness capability, but you’re treading dangerously into Moxie territory by then.

I did find the limit of the Sirius, and I can’t say I was surprised. Aberfoyle’s steeps definitely got both me and the bike out of the comfort zone. The 130mm fork capability of the Sirius is something I would go for, as at full bottom out, the 120mm SIDs fitted did make the front end feel a little low. Again, this was at the upper end of what anyone should think to do on such a bike, and a Moxie might be the better option for that kind of nonsense.

Where the Sirius really shone was if I fancied a ride that had everything. My last outing on the Sirius was exactly that. 32 miles with a mix of fire road, singletrack, forestry paths, more singletrack and a bit of road for good measure. The Sirius was in its element.

What do we think?

The Pipedream Sirius S5 is a cracking do-it-all machine, it really does have a knack for being good everywhere. The slim tubeset and that turquoise is really something else too.

We love:

  • Steel is real
  • Outright versatility
  • That colour

Could do better:

  • Lacks twang

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