SDG (Speed Defies Gravity) - makes the I Beam seat post and is revolutionary.

We have two of them up for sale. The sizes are we have are 30.9 and 31.6 diameter.

The 30.9 is new in the original box. The 31.6 was mounted and used several times but is in perfect shape.

We also have an SDG Formula FX IBEAM seat to match it. You can see that in another add here in the Garage.

We do not accept refunds on items sold in the Garage Sale so make sure you choose the right size for your seat post.