bikemaniac72

http://www.chainreactioncycles.com/Models.aspx?ModelID=79604 here is an iBeam post that costs under $40 and weighs 205g. http://www.chainreactioncycles.com/Models.aspx?ModelID=6066 here is a thompson post that costs $95 plus the cost of the adapter and weighs 228g plus the 70g of the adapter means it really weighs 298g. I'm having trouble seeing why one would buy the adapter instead of the ibeam post, unless they already own a nice thompson saddle, and even still i think the extra few dollars to get the new post and shed lots of weight would be worth it.

Isn't having an ibeam all about saving weight, though? You can get a Kore Race ibeam post for under $40 that is only 205g. Thats probably lighter than your Thompson already, even without the added weight of the adapter, and I dont imagine the adapter being much cheaper than that.

You already made the part, I just want to know how much it weighs.

Isn't an ibeam seatpost lighter and cheaper than a thompson? Plus it has more versatility...

What do you mean no weight penalty? It obviously weighs something...