SDG I-Beam seatpost review

Tough and easy to adjust

BikeRadar score3.5/5

The SDG I-Beam system isn’t new, but you’ll be seeing a bit more of it in 2012 as several other manufacturers have licensed the design. The seatpost uses a tough single pivoting head and a pair of pinching clamps all working off a single 5mm bolt. 

You have to use it with an I-Beam saddle; various models are available, all of which have a single central rail with serrations on the underside. Loosening the seatpost bolt allows you to adjust the tilt of the saddle and slide it fore or aft.

While it doesn’t look like much, it’s actually pretty bombproof – the fact that many downhillers run the system is testament to that. The 350mm-long post can be had in carbon fibre or alloy and with inline or 20mm set back clamps. We chose the alloy inline version which doesn’t weigh much more but costs a lot less.

Conventional saddle design often uses flex in the rails to add a little comfort; there's none of that with the I-Beam system, which results in quite a 'direct' feel. The post does flex slightly though, if you've got enough exposed shaft, which takes the edge off bumps. This feeling is amplified a little more (adding to the comfort) in the more expensive (and lighter) carbon version. 

Guy Kesteven

Freelance Writer, UK
Guy started filling his brain with cycle stats and steaming up bike shop windows back in 1980. He worked the other side of those windows from '89 while getting a degree in “describing broken things covered in mud" (archaeology). Dug historical holes in the ground through the early '90s, then became a pro bike tester in '97. Guy has ridden thousands of bikes and even more components the world over since then and can remember them all in vivid, haunting detail. Can't remember where the car keys are, though.
  • Age: 44
  • Height: 180cm / 5' 11"
  • Weight: 68kg / 150lb
  • Waist: 76cm / 30in
  • Chest: 91cm / 36in
  • Discipline: Strict sadomasochist
  • Preferred Terrain: Technical off-piste singletrack and twisted back roads. Up, down, along — so long as it's faster tfhan the last time he did it he's happy.
  • Current Bikes: An ever changing herd of test machines from Tri bikes to fat bikes and everything in between.
  • Dream Bike: His Nicolai Helius AM custom tandem
  • Beer of Choice: Theakston's Old Peculier (not Peculiar)
  • Location: Yorkshire, UK

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