CrankBrothers Cobalt 3 seatpost review

Solid performer

Our rating 
3.0 out of 5 star rating 3.0
GBP £80.00 RRP | USD $120.00
Crank Brothers Cobalt 3 Seatpost

Our review

The Cobalt is a cleverly designed, solid performer with a head that binds tight
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We’ve been using the carbon and alloy versions of this post and we’ve been generally pleased with the performance of both. The alloy one tested here is good value, well made and light enough to flatter the flightiest of weight-weenies’ bike.


CrankBrothers never back away from avant-garde design and the head of the Cobalt post is clever, unusual and, for the most part, foolproof. A single bolt pulls two clamps in towards the centre of the post where a central plate with curved rail guides supports the inside edges of the rails. When done up tight, the Torx T25 bolt creates a very strong hold on the rails.


That said, we’ve had issues with the clamp and a single Fizik Gobi saddle that we couldn’t resolve without recourse to some cola can shims to pad out the rails – odd as both are designed around 7mm rails. With all other 7mm rail saddles including other Fiziks, we’ve had no issues. The post is available with inline or 20mm set back heads.

Product Specifications


Name Cobalt 3 seatpost (12)
Brand CrankBrothers

Description *Material: 7075 alloy *Weight: 234g *Length: 350, 400mm *Sizes: 27.2 (tested), 30.9, 31.6, 34.9mm *Colours: Iron/blue, iron/black, black/red