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A 3-spline 20-tooth sprocket designed for Nexus geared hubs, compatible with manual Brompton G line models.
A 3-spline 20-tooth sprocket designed for Nexus geared hubs, compatible with manual Brompton G line models.
Brompton

Brompton Shimano Alfine G Line 20T Sprocket

£15.00
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With Pre-Launch, the date when we expect to receive the product ourselves is still a little too hazy to be confident in accepting Pre-Orders.

So, instead, you can submit your email address against the item you are interested in and we will email you as soon as stock arrives on the system.

Estimated Delivery & Collection Dates

Estimated Delivery & Collection Dates are given on Pre-Order and Pre-Launch products. They are for indication purposes only and can change at any time without notice.

The dates we provide are based on indications given by our suppliers. Whenever we get updated information from our suppliers we will endeavour to update the Estimated Delivery & Collection Dates provided on product pages.

We estimate this will be ready for despatch to you or collection via Click & Collect on Undetermined
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In the unlikely event that you are not satisfied with your purchase please feel free to return your items within 90 days of the purchase date for a full exchange or refund. Any item (excluding food, underwear or e-gift vouchers) can be returned to us for any reason within 90 days, provided that the item has not been used or fitted and is returned in its original packaging with valid proof of purchase.

It is recommended that you use a recorded delivery service or return to a store to ensure your items are received by us. We cannot assume responsibility for items that are lost in transit back to us.




Terms & Conditions

Items must be returned in their original packaging and unused. Refunds will be issued once the product(s) have been received and inspected.

Click & Collect customers can buy with confidence knowing that they can review the item before deciding whether it is right for you before leaving the store. Should you decide it's not right for you, it can be conveniently exchanged or refunded straight away, or you still have up to 90 days to return it if you are still unsure.

Please note:
1. If the items we have sent you are faulty, damaged or not as we described, we will cover the cost of collection and the delivery of the correct item.

2. If we have delivered the correct bike but upon inspection, you decide the bike is not the one for you, we will charge you £50 for collection (£100 from Northern Ireland). If you do not have the original box in usable condition, we will charge you an additional £15 to provide one.

Refunds will be processed using the same method of payment used for the original purchase. Credit & debit card refunds must be made to the card used for the original purchase.

We are unable to offer a refund without a valid proof of purchase.

Brompton Shimano Alfine G Line 20T Sprocket

Season:All Year Round

Brand:Brompton

Code:Q103823

The Brompton 20T sprocket is designed for Nexus geared hubs and is compatible with the manual Brompton G line. This 3-spline, 20-tooth sprocket is a direct replacement component for your drivetrain.

Removing the Rear Wheel

  • Gear Selection: Ensure the bike is in the highest gear, 8.
  • Cable Disconnection: Push the tab washer clockwise to disengage the gear cable, then pull the gear cable to disconnect it from the cable slip.
  • Chain Catcher: Undo the chain catcher arm using a 2mm Allen key and pull it upwards.
  • Chain Slack: Remove the chain from the chain ring to provide slack.
  • Wheel Removal: Undo the wheel nuts using a 15mm spanner, then remove the tab washers and the bolts from the axle.
  • Wheel Extraction: Remove the wheel from the dropouts and take the chain off the sprocket.
  • Brake Caution: Do not squeeze the brake lever while the wheel is out, as this will cause the brake pads to touch.
  • Sprocket Removal: Remove the sprocket by taking the circlip off using a flat-head screwdriver.

Fitting the Rear Wheel

  • Sprocket Installation: Install the new sprocket and secure it using the circlip.
  • Alignment: Rotate the assembly until the cable bracket is parallel with the drive-side chain stay.
  • Chain Placement: Loop the chain around the sprocket and insert the wheel fully into the dropouts.
  • Brake Check: Ensure the disc rotor is positioned correctly within the brake pads.
  • Washer Placement: Insert the tab washers, ensuring the white washer is placed on the non-drive side.
  • Tightening: Using a 15mm spanner, tighten the drive side first, then use a torque wrench to tighten both sides to 30Nm.
  • Final Assembly: Refit the chain on the chain ring and re-install the chain catcher.
  • Cable Reconnection: Push the gear cable into the cable clip, rotate the assembly clip, and push the flat side of the cable nut into the slot.
  • Verification: Check that the gears are working properly; indexing should not be required.
Technical Information
  • Origin
    China
  • Teeth
    20T
  • Spline count
    3
  • Compatibility
    Nexus hubs, Brompton G line (manual)
  • Torque
    30Nm
Sizing Information
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