Quick Summary
The PLATT Bicycle Seatpost Shim is an aluminium alloy adapter for converting a 30.9 seatpost to fit a 31.6 seat tube. It is stated as 100 mm long, so the key buying check is matching the seatpost and frame tube sizes before choosing an offer.
Key Details
| Detail | Verified information and buyer relevance |
|---|---|
| Brand | PLATT, as named in the product identity. |
| Product type | Bicycle seatpost shim / bike seat post tube adapter. |
| Size | 30.9 to 31.6. Check the seatpost and frame seat tube sizes before buying. |
| Length | 100 mm. The stated length is relevant to how much support the shim provides inside the frame. |
| Material | Aluminium alloy. |
What to Compare Before Buying
- Seatpost size: This shim is for a 30.9 seatpost being used in a 31.6 seat tube.
- Frame seat tube size: Measure the bike frame seat tube carefully so the adapter matches the opening.
- Length: The stated 100 mm length is a useful check if you want the shim to sit correctly inside the frame.
- Material: Aluminium alloy is the stated material, so compare it with the finish and setup you want for the bike.
Before You Decide
Confirm the 30.9 to 31.6 sizing before choosing an offer, and measure both the seatpost outside diameter and the frame seat tube inside diameter. Also check that the 100 mm length suits the way you want the shim to sit in the frame.
