OneUp Components ISCG05 Underbash

ISCG05 Underbash


Regular price£49.50
VAT included. Shipping calculated at checkout.

If you don't need a chain retention device, or your bike has an integrated chain guide, you can still add some bash protection with the OneUp ISCG05 Underbash.

The Underbash includes 3 different sizes of bash plate for compatibility with chainrings from 28-36T. Designed for frames with 2 ISCG05 tabs only (Deviate, Evil, Rocky Mountain, etc). Should not be used on frames with 3 ISCG05 tabs. Check with your frame manufacturer to be sure the tabs are strong enough. We run these on our Deviates with no problems.


  • Install without removing your cranks.
  • Single tool install and adjustment.
  • Boost compatible.
  • Oval compatible
  • Stainless Steel hardware
  • Includes 3 bash plates (28-30T, 32-34T, 36T)

UK Delivery

Orders Over £50 – Free (Royal Mail)

Orders Under £50 – £4.95 (Royal Mail)

FedEx £5.95

Our standard delivery time is 3–5 days. We do our very best to deliver orders within this time, but occasionally there are delays outwith our control, caused by either suppliers or couriers.

UK Bike Delivery

We offer free UK delivery on all bikes unless bought through a Ride To Work Scheme.

We don't currently deliver complete bikes outside the UK.

Custom-built bikes can be delivered in kit form (for you to assemble) – we can include shipping to your country in your quote.

International Orders

Due to the number of delivery options, the best way to get a shipping price is to add what you would like to your basket and begin the checkout. You'll be able to see the shipping price before you checkout.

Unless IOSS applies (see below) our website will remove UK VAT. You are likely to be liable for tax and duties in your delivery country.

IOSS - EU Orders Under £130

Tax and duties will be calculated at the checkout. Once you have paid 20Twenty, you will have nothing to pay in your delivery country.

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  • Weight: 68g 32-34T
  • Capacity: 28-36T
  • Chainline: 2.5 mm adjustment.
  • Mount: ISCG05 2-Bolt ONLY
  • Colour: Black
  • Material: 7075 aluminium, glass reinforced thermoplastic.

Underbash Setup Instructions

  1. Hold backplate directly against ISCG05 tabs. Check for clearance between the back side of the bashplate and the bike frame (use included 2.5 mm spacers if necessary to space the backplate away from the frame).
  2. Rotate backplate to desired location and torque bolts to 5Nm

Bash Replacement Instructions

  1. Remove Underbash from bike
  2. Remove bolt retaining clip from rear bash plate bolt by pushing a 4 mm hex through the bolt from the backside of the underbash. 
  3. Remove Bash bolts using a 5 mm hex 
  4. Select desired bash plate and reinstall bash bolts to 6Nm 
  5. Reinstall bolt retaining clip on the rear bash plate bolt

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