Alloy Bike Seatpost Shim, 100mm Length Aluminum Bicycle Reducing Sleeve Seat Post Tube Adapter, Diameter Switch 25.4-27.2mm; 27.2-28.6/30.0/30.4/30.9/31.6mm; 30.9-31.6mm.

I needed an adapter like this to move my expensive Kinnekt seatpost from an old bike to a new bike. I chose this one for 2 reasons:1. The longer length should help more firmly secure the seatpost in the down tube. I see a lot of shorter ones on here and worry that they may provide an opportunity for the seatpost to pivot, which could stress my bike frame.2. Other reviewers say it is precisely machined and they are right. It slid right in perfectly and I BARELY tightened my previous setting.I would recommend this one and would buy it again if I needed another. I thought that I needed to buy another $280 Kinnekt, but this inexpensive item saved me the $$$!!!

It wors as advertised and is a effective shim.

I’m so tired of every bike having different seat post diameters that I took a chance and ordered this shim. It dropped it into the seat tube and it fit perfectly. Now I use the suspension seatpost and saddle off my other bike, despite the seatpost size mismatch. Clamped in nice and tight, there’s literally nothing wrong with those approach and it’s much cheaper than buying a whole new seatpost.

These work good. Slip in easy. The only complaint I have is they allow the seat to turn when looking over my shoulder. Wish I could get the tighter

Perfect and good price point.

This shim worked perfectly on my Aventon E 500.3.

Had to build a 31.6 mtb bike using a 30.9 seat post and this worked just fine. I don’t plan on using it on the trails, but I don’t see any reasons not to.

Shim for dropper post. Works. Feels like plastic. I’m concerned about long term durability but we shall see.

I watch E-Bike Reviews and Adventures with Richard. He showed You Tubers this metal shim to use on the Lectric Expedition Cargo e-bike - seat post. I wasn’t going to use a shim, but he had the video, link and showed how well it worked. I decided to buy this shim, even though it was costly.This metal shim was of high quality and the key of course is to buy the precise metal shim required. I called Lectric first to see if they would give me the information I needed and they couldn’t. The idea being, Lectric would be recommending another business that sells a better suspension seat post than the metal shim for their Lectric Expedition. I expect the reason Lectric never had this information readily available for their customers was simply competition to their products.Ok, now was Richard’s suggestion of this particular metal shim for the seat post good? Yes it was!! Boy was I happy when I put my new Suntour NCX suspension seat post together with this metal shim and it fit precisely as recommended!Hats off to Richard’s recommendation and also the manufacturer that makes this metal shim, no one wants a receiving seat post tube broken, as that essentially breaks your frame.After I got through the thrill of victory with this metal shim working. I started off on my brand new Lectric Expedition e-bike and the control box was defective - it just completely stopped working! To top that off, Lectric never had a new control box in stock at Phoenix. AZ and had to order a new control box from China. THE AGONY OF DEFEAT!! The shim worked and the control box never. I ordered the bike May 23rd/24, finally got the bike July 29/24. Now Lectric won’t have my part until August 23/24. So the defective control box took away my pure joy of the metal shim working.