You might also be interested in these bike seat rail clamp.
BBB Cycling Bike Seatpost Clamb Single Bolt Screw-on Seat Post Clamb for Aluminium Seatposts Roadbike, MTB and E-Bike | Black 31.8 mm CarrierClamp BSP-99
UPANBIKE Extra Long 17.7inch (450mm) Bike Bicycle Aluminium Alloy Seat Post with Micro Adjust Clamp (φ 25.4mm)
To fit frame seatpost hole: 25.4mm, Extra long: 17.7" (45cm); Help to raise height of saddle, so that tall rider don't have to bent much forward
£ 15.99
free shipping
To the product (1 offer)
Bike Seat Post Clamp, 7x9mm Bike Seat Post Tube Clip with Install Screws | Saddle Rails Adapter Oval Round Clip, Ergonomic Design, Aluminum Alloy, Enlarged Contact Clamping, for Cycling Accessory
equlup
£ 16.89
free shipping
To the product (1 offer)
HOUSON Aluminum Alloy Bicycle Saddle Clamp for Road Bike, Black, 27.2x31.8mm
HOUSON
£ 9.99
free shipping
To the product (1 offer)
Ritchey Complete WCS Clamp Set For Seatpost With 1 Fiber Screw | Saddle Rail Clamp Attachment, Interchangeable 1 Screw Design, Multiple Sizes Rails, Alloy & Carbon Versions 1-Screw
Ritchey
£ 20.58
To the product (2 offers)
Brooks Saddles B33 Bicycle Saddle with Clamp (Chrome Rails, Black)
Brooks England
£ 206.69
free shipping
To the product (1 offer)
FIFTY-FIFTY Bike Seat Post Clamp, Aluminum Alloy Bicycle Seatpost Collar | 28.6/29.8/31.8/34.9/36.4/38.6mm Bicycle Seat Tube Clip, Secure and Stable, Compatible with MTB, Road Bikes (38.6mm, Black)
FIFTY-FIFTY
£ 15.99
free shipping
To the product (1 offer)
5% off
2 Pieces Aluminium Alloy Bicycle Seat Post Clamp 27.2 mm Quick Release Black Collar for MTB Road Bike Folded Bicycle
Bigxin
£ 8.80
free shipping
To the product (1 offer)
Standard Rail Saddles, 2PCS Bike Seat Clamp, Metal Bicycle Saddle Clamp, Seat Clamp for Standard Rail-type Bicycle Saddle
1.Material: Using high quality made of iron, solid and not easily broken.
£ 14.59
free shipping
To the product (1 offer)
7x9mm Bike Post Clamp, Tube Clip Aluminum Alloy Saddle Rails Tube Clip for Cycling
POENVFPO
£ 14.70
free shipping
To the product (1 offer)
Seat Rail Clamp MEETOOT Bicycle Seat Fixing Clip For Standard Rail Saddles, Bicycle Seat Adapter, Single Rail Saddle Clamp, BIKE Seat Clamp
MEETOOT
£ 9.55
free shipping
To the product (1 offer)
Which.One Highlight
ONIPAX Bike Seat Clamp for Standard Rail Saddles | Steel construction, road cycling upgrade, secure saddle angle locking, universal bicycle adapter
