Argon 18 Argon 18 Sum - Ultegra Di2 - Smoked Nickel - (S) - 2025

£4,499.00  £5,750.00

Finance available with Novuna Personal Finance

Limited Stock Available
S

Part Number:

SUM.S.377A.2D.1

All Together Faster

Decisions, decisions… made easy. With a bike that gives you flat-out advantage on the climbs, the sprints and the straightaways, the only decision you’ll need to make is how nice you want to be to the other guys.

A rider-oriented design approach ensures a frame that is both rooted and responsive, with a ride experience most aero frames can’t match. With a layup engineered to maximise aerodynamics while keeping weight low, the design process for the Sum allowed us to strip away all unnecessary weight within the new aero profile tube shapes - all while maintaining maximum power transfer.

Professionally Built Before Dispatch

Every bike purchased from On It Sports is built in-store by our experienced team and undergoes a full pre-delivery inspection (PDI) before being carefully prepared for shipping.

We take pride in ensuring each bike leaves our workshop properly assembled, checked, and ready for final setup, helping you enjoy a smooth and confident first ride.

Some final assembly will be required on delivery, but we aim to keep this to a minimum wherever possible.


Free UK Mainland Bike Delivery

  • Free UK mainland delivery on bikes over £1000*
  • Bikes are professionally built, checked, and securely boxed before dispatch
  • Shipped using trusted UK courier services

*Bikes purchased through Cycle to Work schemes are excluded from free shipping.

A standard bike delivery charge of £45 applies.


Collect In Store & Free Basic Bike Fit

If you choose to collect your bike from our store, you’ll receive a free basic bike fit as part of your collection.

This includes:

  • Correct saddle height and position
  • Basic reach and comfort checks
  • Confidence that your bike is set up correctly from day one

Once your bike is ready, we’ll contact you by email to arrange a convenient collection and bike fit appointment.


Returns, Refunds & Exchanges

If you’re not completely satisfied with your purchase, please let us know. We offer a 30-day return or exchange period on items purchased with a valid receipt.

To be eligible for a return or exchange:

  • Items must be unused and in a resaleable condition
  • Original packaging, accessories, labels, and any free or promotional items must be included

Returns requested after 30 days cannot be accepted.

Save with Cycle to Work

We accept Cycle to Work vouchers on most full-price bikes through a wide range of approved schemes. Simply choose your bike, proceed through checkout, and select your Cycle to Work scheme at the payment stage.

Our checkout will guide you through the process, including any additional information required by your chosen scheme.


What You Can Include

Your Cycle to Work voucher can be used on:

  • Bikes
  • Helmets
  • Shoes
  • Clothing
  • Essential cycling accessories

This allows you to maximise your voucher and get everything you need in one purchase.


Using Cycle to Work at Checkout

When you reach payment:

  1. Select Cycle to Work as your payment option
  2. Choose your scheme from the dropdown list
  3. Enter the required voucher or scheme details
  4. Complete checkout

Our team will then process your order and contact you if anything further is required.


Important Information on Sale Bikes

* Sale bikes purchased using a Cycle to Work voucher may be subject to a surcharge.

This reflects the commission charged by Cycle to Work scheme providers.

If you’re considering using a Cycle to Work voucher on a discounted bike and want to confirm pricing before ordering, please contact us and we’ll be happy to help.

  • Frame - Argon 18 SUM, full carbon
  • Fork - Argon 18 SUM
  • Headset - FSA Headset NO.55R 1.5'' + 3D
  • Wheels - Scope R4
  • Tyres - Vittoria Corsa N.EXT TLR 28c
  • Tyre Clearance - 30C (32mm)
  • Bottom Bracket - BB Ultegra SM-BB72
  • Front Derailleur - Shimano Ultegra Di2 R8150
  • Rear Derailleur - Shimano Ultegra Di2 R8150
  • Crankset - Shimano Ultegra R8100 52/36
  • Chain - Shimano Ultegra CN-M8100
  • Cassette - Shimano Ultegra CS-R8100 11/30
  • Shifters - Shimano Ultegra Di2 R8170
  • Brakes - Shimano Ultegra RT-CL800 / F:160mm R:140mm
  • Handlebar - FSA Energy SCR Compact
  • Bar Tape - Ciclovation LEATHER TOUCH Tornado Gloss
  • Saddle - Repente Quasar
  • Seatpost - Argon 18 Sum specific

Colours Smoked Nickel
Sizes S
Brand Argon 18
Model Year 2025
SKUs / Part Numbers SUM.S.377A.2D.1

Please note: Manufacturers can sometimes change the specification of the products from time to time.