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Thomson Seatpost Collar Black
Thomson Seatpost Collar Silver
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Thomson Seatpost Collar Black
Thomson Seatpost Collar Silver

Seatpost Collar

Mfg PartNum:
  (2 customer reviews)
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Built & Tested To The Same Standards As Thomson Aerospace Components

The Thomson seat post collar is made from the same 7000 series alloy as our seat posts and stems, giving you the high performance and long life you expect from a Thomson.

The collar utilizes Thomson's seat post bolts, washer, and barrel nut hardware design that has proven to be an industry leader since its inception. This fastener combination allows float on both sides of the collar slot ensuring consistent clamping force.

The bolt hole angle, height of the collar, and offset slot all help create a seatpost collar that generates maximum clamping force at only 25-inch pounds of fastener torque.

Own a Thomson seatpost and stem? Complete the trifecta with a Thomson seatpost collar.


  • Manufactured in the USA
  • Iconic Thomson engineering and design
  • Available in black or silver finish
  • Available in 28.6, 29.8, 31.8, 34.9, 36.4mm sizes
  • Weight: 25g (28.6mm)

B-Stock - This product has one or more B-Stock units available. These units can be purchased at a discount (see option select). B-Stock units were returned from other customers and may have missing or damaged packaging materials. These units are otherwise as new. The full manufacturer warranty applies. Click Here for more information.

The product weight specified is an approximate weight based on the manufacturer's specifications (if available) or our measurement of one or two examples. For most products, the weight will typically vary by 5% to 10%.


Seatpost Clamp: 28.6 

28.6mm - Black

Weight: 25 grams

Mfg PartNum: SC-E101-BLK 

29.8mm - Black

Weight: 26 grams

Seatpost Clamp: 29.8 

Mfg PartNum: SC-E102-BLK 

31.8mm - Black

Weight: 28 grams

Seatpost Clamp: 31.8 

Mfg PartNum: SC-E103-BLK 

34.9mm - Black

Weight: 30 grams

Seatpost Clamp: 34.9 

Mfg PartNum: SC-E104-BLK 

36.4mm - Black

Weight: 34 grams

Seatpost Clamp: 36.4 

Mfg PartNum: SC-E105-BLK 

28.6mm - Silver

Weight: 25 grams

Mfg PartNum: SC-E101-SLV 

29.8mm - Silver

Weight: 26 grams

Seatpost Clamp: 29.8 

Mfg PartNum: SC-E102-SLV 

31.8mm - Silver

Weight: 28 grams

Seatpost Clamp: 31.8 

Mfg PartNum: SC-E103-SLV 

34.9mm - Silver

Weight: 30 grams

Seatpost Clamp: 34.9 

Mfg PartNum: SC-E104-SLV 

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2mm head bolt is easy to strip
by old1
Cycling Enthusiast
Atlanta, GA
1 of 1 customers found this review helpful.

Clearly a high quality piece, but it did not work for me. I am using a carbon seat post in an aluminum frame , so I have to install the clamp in a 'reversed' position with the bolt of the clamp on the front side of the post, opposite to the flexible open part on the rear part of the seat post. The recommended 2.8nm torque spec was not enough to keep the seat post from slipping. Applying just slightly more torque caused the tiny 2mm headbolt to strip, meaning a trip to the bikeshop to have it drilled out. 2mm is just too small. I switched to a clamp with a 4mm headbolt and all is good now.

Reviewed 2/22/2022
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Top notch
by Anonymous

Thompson is hands down one of the best as most know . This collar is rock solid and I am extremely happy with the purchase.

Reviewed 12/2/2022
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