That's what I decided to do for this season. I started riding LD in 2006, completed PBP in 2007 and Randonneur 5000 in 2009. I got a recumbent (Performer HR) hoping it would be more comfortable and faster for LD and hopefully for PBP in 2011. I've done about 1000 km on the bent (since november) and I'm still definitely slower than on the DF. Today I rode a 100 km Audax (so with a captain keeping the speed at 22.5 km/h) and I got dropped after 5 km and never came back on the main group. I ended up finishing about 30 mn after the main group. I wasn't able to ride 100 km at 22.5 average on a fairly flat route (plus I ended up with a painful knee), while I could ride 100 km at 27-28 km/h without any problems on a DF!
So, is it supposed to be that hard? How much time will it take before I can ride as fast on the bent as on the DF on brevets?