difference between semi recumbents and recumbents?

What is the major difference between semirecumbents and recumbents?

The definitions are still being evolved. Used to be that anything with forward pedals and a nice seat qualified as a recumbent if the mfg wanted it to. The term, "nice seat" could mean anything from a real SEAT to merely a cushy saddle. Current thinking is that if the seat adjusts vertically then it's a semi-bent and if it adjusts horizontally then it's a full 'bent. Real 'bents don't have seatposts.

My personal definition also includes the requirement of a functional backrest (not just a hip support) to qualify as a real recumbent. There's also the question of seat-to-BB angle, but nobody has come up with universally-accepted parameters yet.

My recumbent has a seat that adjusts horizontally but the arbiters of what constitute REAL BENTS would dismiss it as not a "real" recumbent. That is because it has a saddle rather than a lawnchair to sit on.

My view is that the differences are very minor and each (so called SEMI-recumbents, and so called REAL recumbents) have their pros and cons. I'm not as low on mine, which could be an advantage in traffic and it is easy to get it rolling from a stop. REAL bents have the advantage of giving you a "barcelounger" to nap in while riding.

This (bogus) distinction reminds me of arguments I have heard on ham radio message boards regarding who is a real ham and who isn't. In the end, we ride whatever gives us pleasure. Watch out for false claims that bikes such as the Evox are for short distance "Fred" rides around the trailer park with the grandkids. I ride mine hard over the same courses and distances I ride my Bianchi road racer. My distance expands daily. I've put over 300 km on this bike in the past two weeks.

Cheers

Charles

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"If something is worth doing, it's worth doing poorly."

"My other car's a Bianchi!"

The difference that I notice most is the angle of the riders back and legs while riding the bike. Most of the bikes that I would class as fully recumbent have the rider's back reclined past the perpendicular angle so they need to have a full length back rest to support the weight of the rider's back. Additionally, I agree that the seat to bottom bracket angle is horizontal on most bikes that are recognized as true recumbents.

On the other hand, the seating position on a semi-recumbent promotes the rider to a vertical back position with the bulk of the weight being supported by the saddle or seat. This explains why the smaller hip rest is more than adequate for the semi-recumbents. I've seen some bikes that call themselves semi-recumbent that have no back rest at all. The seat to pedal angle is diagonal on a semi-recumbent and this geometry compliments the back angle to reduce the bend at the hips that plagues most drop down handlebar road bikes.

Having looked at the Burley line of recumbents, there are a few models that have the rider in the same basic position as with my Evox...and they are recognized as recumbent and the Evox as semi-recumbent. In these cases it is like splitting hairs really...who cares as long as the person is happy with their respective machines.