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Simply Metal

Single-speed, Jack-Drive, Downhill for Metal Heads

The Starling Sturn V2 is a flat-out, ass-hauling, race-winning monster of a downhill bike that dares you to think differently.

Perfect for racers gunning for the top step or seasonaires hunting for hassle-free seasons, the Sturn is big travel, single-speed, has options for all wheels sizes and a Jack Drive suspension system.

The Jack Drive design allows the suspension and drivetrain to run through the same pivot, meaning no chain growth and the ability to run the bike single speed without dropping chains. The effect is beautifully supple rear suspension and zero distractions from your hunt for the top spot.

Not sure if the Sturn is a race bike? How about if we told you Brett Wheeler raced it to win Masters European DH Champs and the overall Portuguese National Downhill Championship Masters title?

29″ / 27.5″wheels
For the top step
200mm / 200mm


  • Front triangle and swingarm hand-built in Bristol, UK, using Reynolds 853 heat-treated tubing.
  • 27.5″, mullet or 29″.
  • 200mm rear travel.
  • 200mm front travel.
  • Comes complete with proprietary Jack Drive system manufactured from 7050 aluminium.
  • Jackshaft uses standard screw-on track cogs for easy replacement.
  • Multi adjust shock mount to fit a full range of shock sizes and allow geometry fine-tuning.
  • 140mm high pivot.
  • Ridework eccentric bottom bracket.
  • ISCG05 bashguard mount.
  • 2.8″ tyre clearance.
  • Up to 200mm rotor.
  • Custom sizing on all frames.
  • Works with left-hand drive cranks, Middleburn and Profile available.
  • Designed for single speed 142x12mm rear hubs.
  • Unique Starling dropouts system means rear wheel can be removed without adjusting tension.
  • Geared dropouts available on request.
  • Seat tube reinforcing strut on larger sizes.
  • Integrated seat-clamp.
  • Stainless and numbered dropper port.
  • Starling headtube gusset.
  • Custom colour options available.
  • Choose frame-only or full builds.
  • Funn, Hope, Öhlins, RockShox, Middleburn available.


  • with standard paint
  • Shocks from £705

Why starling Cycles?

Starling Cycles are made by real flesh-and-blood humans. The perfect blend of precision and passion.

Our frames are hand-crafted with quality, lightweight steel for an unmistakable feel and undeniable speed.

Our single-pivot suspension design eliminates complexity. A blast to ride and a breeze to maintain.

Geometry and sizing

Starling Cycles Sturn Geometry diagram
Wheel size29″MX27.5″
Rider size rangecustomcustomcustom
C.Head Angle63° recommended63° recommended63° recommended
D.Seat Tube Lengthcustomcustomcustom
E.Head Tube Lengthcustomcustomcustom
F.Fork Length200mm recommended200mm recommended200mm recommended
I.BB Drop30mm15mm15mm
J.Seat Angle76°76°76°
K.Effective Top Tubecustomcustomcustom
Max Seat Post InsertionNANANA


Travel 200mm
Shock 250 x 75mm Metric
Headset Top ZS44/28.6
Headset Bottom EC44/40
Seat Tube 31.6mm
BB Rideworks Eccentric
2437 LLU bearings
Seat Clamp Integrated
Chain Device None
Bash Mount ISCG05
Rear Axle Rear Axle, 142x12mm
Max Tyre 2.8″
Brake Mount IS
Max Disc 200mm
Front Shock Hardware 30x8mm
Rear Shock Hardware 35x8mm
Main Pivot Bearings 2437 LLB

Why Sturn V2?

The Sturn V1 always worked very well, but the Jackshaft and chain tensioning solutions weren’t as refined as we’d like.

For V2 the BB and main pivot region have been completely redesigned, as well as a proprietary new Jack Shaft solution. The swingarm has been totally redesigned to be super neat and with reliable eccentric dropouts.

High pivots only work if you can control chain growth issues. An idler pulley is a decent solution, but the Jack Drive is the proper way to reduce friction, reduce chain forces and eliminate chain growth. Combine that with a super light, single speed rear wheel and you have suspension that feels absolutely sublime.  It tracks super rough terrain, it absorbs impacts beautifully and it carries speed like nothing you’ve ever ridden.

We can do a geared version of the bike if you ask nicely. But the single speed is where it’s at. Perfect chain line, super light and strong rear wheel, super low maintenance. What if you had your best race run ever? Was it because you changed gear at the right time, or you could ride with total focus and flow, in total silence with zero distractions?

Build kits

Your dream build needn’t be a nightmare. We can supply your frame with or without a shock and with build-kits to help you complete your masterpiece.

We’ve hand-picked some of the very best brands in the business, brands that we’ve personally ridden and rated. This includes Funn, Hope, Öhlins, RockShox, Middleburn, Magura, BikeYoke build components available.


“The new Starling Sturn is the downhill bike of your metal-head dreams.”

“Starling Cycles stole the show with this mildly bonkers 29″ wheeled, steel framed singlespeed downhill concept bike.”


The Radivist
“Starling Cycles tackled the DH SS problem with a truly unique suspension design.”

Full custom

We exist to create the perfect bike for you and your trails. Beautifully simple, brutally fast.

For those that need something a little extra, we offer full custom reach, seat tube length, head tube length, head angle and fork length. We can also customise travel to create short, mid or long travel setups.

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Fancy something else?

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