Recumbent - View of the road surface?

Hi bent riders....

I am toying with a conversion of our Tandem upright into a 50/50 - bent/upright.
The Captain's position (mine) being the bent one.

When tandeming the Captain has to relay information about the road surface constantly back to the Stoker, because the Stoker has no view forward apart from the Captain's back. If I hit a pothole without saying anything, my stoker gets an unexpected and unpleasant wack in the nether-regions.

The 50/50 setup will give my Stoker an improved view forwards, BUT...Something that is concerning me is the view forward at the road surface from the bent position. I have the impression that legs, pedals, cranks, stearing etc obscures a near view of the road. Correct????

Thanks in advance for your help...

I bet spuds is going to reply to this with some really funny photos.

About the tandem, I think it sounds like a good concept. can we see some working drawings?

I'd like to see drawings, too. I guess you could give the captain underseat steering, but if you're going to do that, why not give the stoker a recumbent seat too? That would at least make vehicle control easier, since the stoker would be less apt to shift her weight if she were on a recumbent seat. Here is a pic of an Opus III Counterpoint (http://www.biketcba.org/TRICORR/members/dward.jpg). I don't know if they're made anymore, but they put the stoker in a recumbent position in front while the captain rides in the upright position behind.

The disadvantages as I see them are 1) stoker envy and 2) a very heavily loaded front wheel. Advantages: 1) no captain envy and 2) captain is positioned aerodynamically behind the stoker, which is not true of most recumbent tandems.

Heh, I want to see the front end of a trike attached to the rear end of a DF to create a tandem. The stoker would be able to see clearly over the driver, and the whole rig would be very stable, because of the three wheels. That would be cool...

Heh, I want to see the front end of a trike attached to the rear end of a DF to create a tandem. The stoker would be able to see clearly over the driver, and the whole rig would be very stable, because of the three wheels. That would be cool...

You could build one and try it. I suspect with the higher center of gravity, and more weight toward the single rear wheel, it wouldn't be very good in turns.

I bet spuds is going to reply to this with some really funny photos.

About the tandem, I think it sounds like a good concept. can we see some working drawings?

No working drawings yet, but the concept is as per the attached.

All expert comment appreciated...

Nice drawing. It looks like the stoker in that pic could see any bumps coming up right over the captain in the front. It also looks like if the stoker gets upset with the captain, she doesn't have to smack him in the back anymore, she can rap on the back of his helmet. ;)

OK, from what I see of the drawing:
1. Steeper than normal steerer tube, resulting in no trail. If you're going to use the front end of an existing tandem frame, you'll need a larger front wheel or something, or else the steering will be very touchy. Perhaps a no-rake fork would help enough, perhaps not.
2. On a related note, the seat tube will also be more vertical. That means a harsher ride for the stoker.
3. Stoker cannot get into aero/drop position without banging heads with captain.
4. Stoker bars will have to be VERY wide as drawn. Both #3 and #4 can be alleviated by lengthening the frame and adding space between the riders.
5. Just to make sure you understand: the stoker on this bike will have to put her feet down at stops and hold the bike up, as well as being in charge of takeoffs. Responsibility for steering and landings usually go together. If the captain plans for a right foot plant and the stoker plans for a left one, an... awkward moment will ensue.
6. 45 degree seat angle (give or take) combined with a relatively neutral bb/seat relationship is not especially aerodynamic, but should be OK for control. Make sure the seat pan is relatively large or recumbutt will result.
7. Stoker should be able to see well enough ahead to plan for bumps even without warnings from captain. I don't know if that would be true if you lengthened the frame.

All of the problems can be designed around. But why? You want a recumbent seat and your stoker doesn't? Or is this just a fun project? :)

Great points. Thanks.
The frame in the sketch is our existing tandem frame, there is just a smaller wheel on the front. I didn't think a small change in height due to the smaller wheel dia would have too much influence on the rake angles, given the long wheel base. But, of course, I will check.

Fun project?.... everything to do with bikes is fun.... ;-)

Or do what Hase do http://www.hasebikes.com/ens/pino/index.php and use the stoker as a crumple zone :)

Or do what Hase do http://www.hasebikes.com/ens/pino/index.php and use the stoker as a crumple zone :)

Cool idea! Though I don't know how I'd feel about putting my child ahead of me like that...