Comparing the Morph II to the Bobby Hall Handcycle (Especially Seat Height and Back Angle)

This series of photos compares the Morph II in low rider with Bill Warner's Bobby Hall handcycle. In this first picture, you can see that the Morph II seat (in the back) is quite a bit higher than the Bobby Hall. This is significant in that the bike is less stable around turns. But also note that that the seat angle adjustment is not all the way down. When that is changed, the Morph II more closely (but not completely) matches the Bobby Hall handcycle. The geometry of the Bobby Hall was used as the "gold standard" for the low rider mode. But it turned out to be harder than we thought to match it exactly.

Same setup from the other side. That's me in photo position.

Here, John Baron is releasing the collar and removing the pins so the two struts will compress and will allow the Morph II to get to its lowest height. These struts and the forward hinge below the seat are part of the seat angle adjustment system that was part of Morph II. However, it turned out that these struts were under huge pressure, and riding shocks created even more force. This caused the locking pins to tear into the metal on the struts. Thus the collars had to be permanently locked. In this photo, John is releasing those locking collars.

Now we've lowered the struts in the front, and the Morph II seat is closer to that of the Bobby Hall. The Bobby Hall uses 26" wheels on front and back. The Morph II uses 700c (about 27") wheels on the rear, and 16" on the front.

Note the difference in the seat back angle. This is very significant. The Morph II in low rider mode isn't comfortable due to the very vertical seat back angle.

This closeup shows the seat angle differences. The camera used its flash, and you see the various reflective materials shining back.

This photo, from the other side (you can see me in the background) shows the dual struts in their compressed state.

Front angle of the two handcycles. Note that the Bobby Hall has 15 degrees of camber on the rear wheels. Camber isn't possible on the Morph because the axel rotates and the camber would be unusable only at one position.

Higher angle front view.

Even higher front view.

Note the difference in rear track width. The Morph looks much wider, but its not that big a difference when you measure at the ground. Note that the camber on the Bobby Hall is very hard on tires, and it seems to reduce rolling efficiency. Rory has changed his Bobby Hall to 9 degrees of camber.

Higher angle rear view.
 
At this point we have two handcycles on the road. Morph II, shown here, is made of steel and weighs 58 pounds. Morph III is made of aluminum and comes in at about 40 pounds. Morph II's geometry is better, and it positions the front wheel and pedals better. It turns beautifully in high rider mode, and in low rider mode. But the seat is uncomfortable and the seat back too steep in low rider mode. The seat angle adjustment system has problems and generally needs to be locked on one place. The result is comfort in high rider, and good performance in high rider, but mediocre comfort in low rider and the too high seating position that you see above.
 
Morph III (not shown here) by contrast has some geometry problems that we hope to fix. It has negative trail in upper and lower modes (not good). The seat angle adjustment is different, but has been problematic to use, and it too is fixed in one position. Ah, seat angle adjustment. We are 0 for 2. On the next morph, we are looking at an automatic mechanism that will correct for seat tilt as you morph.
 
But Morph III's riding position in low rider is much better. It is low to the ground, and more stable. Rory rode it 110 miles (!!) in two days at the World T.E.A.M Sports Face of America Ride with soldiers riding from Washington DC to Gettysburgh, PA this April.

4 responses
A few thoughts:

On Morph 2, changing the seat angle also changes the frame geometry, creating unintended consequences that affect trail values and other morphing attributes. as we move forward it will be very important to separate seat adjustment from the frame morphing geometry.

I believe it will be easy to create a linkage that allows automatic seat angle adjustment as shown here (http://morphhc.posterous.com/self-adjusting-seat-linkage). But Rory has pointed out that it is very important to consider the position of the legs relative to the headset tube so that the legs are not forced into uncomfortable positions as the cycle is steered. I am worried that if the seat adjusts too much relative to the frame, it may pull or push the riders legs in a way that is uncomfortable, or hinders steering.

I agree that the riding position of the Bobby Hall is what the low rider position should be. I think this is do-able.

Thanks for the post, really effective info.
www.encontactos.com
So, I don't really believe it may have success.
Goodness, there is really much worthwhile information above!
rimobel