Co-Motion Steelhead GRX Belt Tandem

“The Steelhead is built for ADVENTURE by us using the best choice of equipment like HOPE HYDRAULIC brakes and hubs linked with MAGURA Rotors. The transmission uses the SHIMANO GRX 810 and a wide ratio to accommodate climbs.

The Steelhead is a unique tandem species, with gravel under its belly and ready for adventure.​ This is one versatile Tandem, whether the road is tarmacked, double-track, or covered with gravel. For some, this tandem will be the ultimate gravel bike for weekend explorations or racing the Land Run 100 and Dirty Kanza. For others, it’s the ultimate Gran Fondo Tandem or light tourer that easily transforms to handle the changing terrain.


  • Optimized for 28″ wheels and 35-40mm tyres with mudguard clearance.
  • Co-Motion Reynolds 631 oversize butted tubing.
  • Tapered Head-Tube combined with a Boost Carbon fork.
  • Proven Co-Motion stable geometry.
  • Gates Belt Drive on Crossover
  • Shimano GRX 810 Shifting.
  • Rack/ Mudguard mounts and dual disc brakes.
  • Hand-built Thru-axle 148/12 – 110/15 wheels.
  • Transmission Shimano 2 x 11 – 11-42
  • Tandem Experience Training is included when you buy.

Buy this Tandem with our Cycle to Work Scheme. Read about specialist Tandem Insurance and also Servicing which with all Tandems purchased from us has 2 years of service included – go to our Services page here.

From £7695, see below to add options and accessories. Configure your Tandem now!
 "We had 'The Tandem Experience', a really excellent introduction to riding a bicycle made for two. Very thorough training on technique for riding a tandem (hint: it's quite different to a normal bike), then a whole day hire of a touring tandem, with a very pleasant 25 mile circular route map supplied. Bike was very good quality, and training unhurried and well delivered. Highly recommended, if you're thinking of trying out a tandem!" James McRae, Local Guide - Google Review

Full Specification

  • Frame: Hand-Built frame with Reynolds 631 Butted steel tubing.
  • Fork: Co-Motion Carbon Tandem with 110/15 Thru-axle.
  • Derailleurs/Shifters: Shimano GRX.
  • Drivetrain: Co-Motion Chainset – 50/34T – Various lengths available.
  • Gates Centre Track Carbon on Crossover Drive.
  • Wheels: Hand-Built with Hope Pro 4 Thru-axle with Halo Vapour 28″ rims.
  • Brakes: Hope Tech 3 V4 with Magura MD4 – 203mm disc rotors.
  • Headset: FSA Orbit Z Internal 1 1/8″ – 1 1/2″.
  • Cockpit: Deda Drop H/Bars and Upturn –  Co-Motion adjustable stoker stem.
  • Seat Post: Deda and Cane Creek G4 ST Thudbuster.
  • Tyres: Continental GP5000 – 700 x 32.
  • Saddles: See Options below – not included in the price.
  • Pedals: See Options below – not included in the price.
  • Mudguards: See Options below – not included in the price.
  • Front & Rear Racks: See Options below – not included in the price.
  • Bottle Cages: See Options below – not included in the price.
  • Other items are shown in our Options and Accessories below.

What frame size do we need?

A common question and one that we do take seriously as it makes the difference of riding a Tandem safely and for long term enjoyment.

How do we work out this? 

Here are some pointers we talk about regularly with our customers.

  • Your ‘Saddle Heights’ are critical and found commonly too low for efficient cycling.
  • Once your ‘Saddle Height’ is correct then your feet will only just touch the ground, by tiptoe.
  • To find the correct ‘Saddle Height’ we require a ‘Standover’ measurement.
  • To do this simply stand with your back to a wall with your cycling shoes fitted, then place a book (approx. 30mm wide) between your legs and position so that it touches you firmly.
  • Then measure from the top of the book to the floor.
  • This measurement is your ‘Standover.’
  • Remove 100mm from this ‘Standover’ measurement and this will leave you with your ideal saddle height to start with.
  • The ‘Saddle Height’ is measured from the top/middle of the saddle to the centre of the chainset.

Now when looking at our Frame Measurements matrix below and look for the Standover in column ‘K/L’.  The measurement shown is the maximum of your Standover for front and rear riders.  Therefore you can look at frames that are lower than this.

Of course, our Custom Sizing Option is available if you are unable to fit the many sizes available.  We charge to produce a TandemCAD for you that is refundable once the Tandem is placed on order. Click below if you wish to go through this process.

Go to our Custom Sizing Option here!


Frame Measurements

Frame Size A/N - Top Tube F/R B/C - Seat Tube F/RE - Chainstay J - Bottom Bracket Drop/HeightD - Head Tube M - WheelbaseI - Fork Offset K/L - StandoverH - Head AngleF - Seat Angle
Medium565/72454/4443672/273 165175150780/6827173/73
Large585/72456/4643672/273 185177150805/7077173/73

Paint Options

Co-Motion Paint Choices

Many colours are available for Co-Motion Tandems in both Opaque (as shown), Metallic and Premium finishes, Upcharges are made on Premium and Finishes.

Co-Motion Decal Choices

Co-Motion offer five styles of decals on their Tandems.

Options & Accessories

Pedals and Clips

We can supply any pedals or you can fit your own if preferred.
Pedals commonly used are: Shimano - 324 SPD / Flat, Shimano - 520 SPD, Classic Alloy (as shown) and Studded Platform. Half Clips can be supplied to fit Shimano 324 and Classic Alloy.


Saddles offered are from: Bioflex Ongel Ozone (as shown) - in various widths. Brooks - all models and Selle Italia - all models.


We fit the correct size for use with the tyre width of your choice and they come in both Black & Silver. Available from Flinger (as shown) and SKS.

Suspension Seatposts

Recommended to fit to the rear position are the Cane Creek Thudbuster ST G4 (as shown) or the System EX EL.


Handlebars can be changed and the following are popular choices. Front - Jones Loop SG 64cm rise (as shown). Front/Rear - BLB Big Smoker Riser Bar 7.6cm rise. Rear - Profile Upturns 47cm wide.

Rear Stem Adaptions

Our Tandems are supplied with a standard adjustable rear stem, however depending on the sizes of both riders the rear handlebars may require to be higher. We supply a sleeve/stem combination to allow this to our existing rear stems. Please contact us to discuss the options. To fit seat post sizes of 27.2mm, 29.8mm and 31.6mm.


Racks for Panniers: Front/Rear - Tubus, Front/Rear - Blackburn and Rear - Topeak Super Tourist DX (as shown).

Panniers & Top Bags

Panniers from Ortlieb & Topeak (as shown with drop down panniers).

Bottles and Cages

Standard aluminium Pulse cages from Zefal and also the superb non cage bottles from Fabric (as shown) in two sizes and in clear or smoke.

Dynamo Package

Schmidt SON dynamo hub (as shown), superb Supernova E3 Pro 2 front light combined with Supernova 3 rear light. This package can be added to a Sinewave Cycles Reactor USB top cap charger for your USB-powered devices.

Sinewave Cycles Reactor USB

Sinewave Cycles Reactor USB top cap charger for your USB-powered devices.


Topeak Road Master Blaster to fit neatly into your frame for your on the move pressure top up and the Topeak Joeblow Turbo Floor Pump (as shown) to keep pressure topped up with ease.


Park Tool Peg Spanner SPA1 to fit all of our Tandem eccentrics. Combine this with a multi tool pack, puncture outfit and tyre levers and your ready for your travels.

Tandem Rak

To transport your Tandem on roof bars, rear of a Transporter or on a TowBar we have them all, please ask for more details.

NeoDrive E-Assist Addition

On Tandems with a vertical quick release drop out we are able to supply as an e-assist upgrade at the point of order. Please contact us to discuss the options.


On some of our tandems a kickstand can be fitted to frame mount, ideal for touring Tandems. The Pletscher Twin leg stand is available in Silver or Black and 26"/27.5"/28"/292 wheels.

Fillet Brazing

On our Co-motion tandems the traditional style of fillet brazing can be offered on all their Tandems.

Extra Bottle Bosses

If there is a need for extra bosses for water bottles over the standard offer then this can be done.

Custom Sizing

This is a standard on our Landescape Tandems but is offered on our Co-Motion Tandems.

S and S Couplings

Only available on our Co-Motion Tandems and can be offered in either two or four couplings. Four is required for fitting into the Co-Motion travel cases or can also be supplied polished as shown.

Co-Motion Headbadge

This can be supplied as an upgrade to any Co-Motion Tandem.

V-Brake addition to Discs

We offer on our Duratec, Landescape and Co-Motion Tandems the facility of a third/parking brake operated by either front or rear by a third lever. The brake and lever costs are additional to this upcharge.

Stainless Road Ends on Rear

This can be supplied as an upgrade to any Co-Motion Tandem.

Extra Headtube Length of 15mm

This can be supplied as an upgrade to any Co-Motion Tandem.

Pathfinder Bosses

If choosing the Dynamo package the extra fitting for Co-Motion are required.

Di2 Preparation

If buying a Co-Motion or Landescape Tandem with Di2 then this upcharge is made to prepare the frame.

Touch Up

Touch Up can be ordered for all of our Tandems.


We recommend the Magura MDR-P 203mm Rotors fitted to our Landescape and Co-Motion Tandems. Offering a special patented interlocking of the outer and inner rings (Dovetail Interlink Technology) giving optimum braking performance even under heavy loads

Cane Creek Ergo Stoker Levers

To be used in conjunction with a drop handlebar to allow a conventional riding position.

Ergon Grips

Ergon - developed for riders seeking the most hand positions. The GP1 grip combined with a 5 finger multi-position bar end featuring rubberised inserts for a positive grip.

How to buy

If you don’t know the size/saddle height you require:

  • Complete a sizing fit either in-store or virtually – click here to book.
  • Choose a Tandem, specification and any accessories via our website (within each Tandem product), over the phone or email or in-store.
  • We will contact you to secure your order with a 50% deposit.
  • Or arrange Finance Options.
  • You will receive a delivery ETA.
  • Take delivery of your new Tandem or global shipping can be arranged.
  • Ride your new Tandem!

If you do know the size/saddle height you require:

  • Choose a Tandem, specification and any accessories via our website (within each Tandem product), over the phone or email or in-store.
  • We will contact you to secure your order with a 50% deposit.
  • Or arrange Finance Options.
  • You will receive a delivery ETA.
  • Take delivery of your new Tandem or global shipping can be arranged.
  • Ride your new Tandem!

Alternatively – contact us (phone or email or in-store) to start a no-obligation, no pressure discussion to decide if a Tandem is for you and how to buy the perfect fit.