Core Bike 2010: I-Beam seatpost from Gravity Dropper

Plus latest Formula seats

SDG’s I-Beam saddles are some of the lightest on the market, thanks to the use of the titular nylon ‘beam’ instead of metal or carbon rails.


The downside is that they have to be used with an I-Beam compatible seatpin, which has previously put them out of reach of riders who run telescopic posts.

That’s set to change, though, thanks to a collaboration with Gravity Dropper which has resulted in a new I-Beam version of their Turbo post, available in the rare (for height-adjust posts) 27.2mm diameter.

The standard spring-loaded, cable-activated post is one of the best on the market. Although it could never be described as a thing of beauty, we think the I-Beam version is actually better looking.

The original is one of the lighter models on the market, at 410g, so teamed with a super-light SDG I-Fly saddle at 155g this I-Beam version could be the telescopic post weight weenies have been waiting for. Price and availability TBC.

SDG i-fly saddle:
Jeff Jones/BikeRadar

SDG Formula saddles

One common complaint levelled at the I-Beam system is that the saddle’s solid hull results in a less comfortable ride than traditional rails.

SDG have addressed that with their latest Formula seats, which feature a redesigned single rail suspended on a ‘hammock’ with a latticework of holes to add a little flex and save even more weight.


Rubberised edges add more comfort, and SDG say this technology is going to trickle down to the I-Fly for next year.

SDG’s latest i-beam saddle rail:
Jeff Jones/BikeRadar