Morph III in high rider mode. Note significant negative trail.
Morph III high rider trail measurement: 3.5" That's way too much. The result of this will be that it's hard to turn tightly.
This photo, taken February 5th, showed the same problem on Morph III before its first round of big modifications. We made some (see post The Morph III Gets Chopped, But That's a Good Thing)
From February 5: With the new main tube taped in place, and with the head tube angle set by adjusting the old seat angle adjustment, we took some quick measurements.
Trail looks to be almost zero.
This closeup of the "chopped" Morph III shows just what we want: Almost no trail in high rider mode. But after that modifications were completed, things changed.
Morph III in partial low rider mode. Note wooden block stopping morph to bottoming. This is a bad thing. It doesn't let us get down as low as we want. But we were having trouble getting the morphing to work, because the 4-bar linkage actually goes over center beyond this point, and that means you can't morph up by pulling the wheels closer to you.
About an inch and a half of negative trail in partial low rider. Also not good.
Wooden block removed. Morph all the way down. (note that the gas springs are removed for making these measurements.)
Even this small amount of morphing down has reduced the trail.
In full low rider mode, trail is about negative 1 inch.
Rear of seat bar is 13 inches.
Front of seat bar is 17". Seat is tilted up. In morphed up position, seat becomes level.
Low rider head tube angle measurement.
Low rider head tube anle of 28.6 degrees looks like its too low. We'll see when we measure Morph II, which seems to have the optimal angles.
With block in place.
Head tube angle with block in place is 32.4 degrees.
Wheelbase measurement with block in place.
Morph III wheelbase is 60 inches.
This is an inch shorter than the CAD design before modifications.
Seat base to pedal center.
Seat base to pedal center - 23 inches.
Wheelbase in partial high rider.
Wheelbase is 46.5". That's long. Much more than Morph II.
Head tube angle in partial high rider is 50 degrees.
Morph III overall height in high rider: 46"
Morph isn't fully collapsed.
Now it is. Note: compare the modified frame shown here with the original frame in the photos from this post: The Morph III Gets Chopped, But That's a Good Thing. We eliminated the forward bushing that was used to allow the rear frame to tilt as a way to achieve seat angle compensation when you morph. We found that that original mechanism was unstable...when you released the pins in the dual support tubes of Morph II, the seat angle would collapse to the lower position, so in actual use we never did change the seat angle during morphing. Now with this modification of Morph III, we added a seat tilt adjustment directly. But the seat back, which is separate, has no adjustment, so the seat design remains in flux. This was just a way to get on the road and get testing.
Also note that we removed the bend in the bottom arm of the morphing frame. Perhaps this is why the modified bike doesn't morph as far back as the original Morph III.
This cuts about 2" off the wheelbase. Very significant. I believe we can use the over-the-center approach to allow the Morph to get very short in high rider mode. Just need to figure out how to GET OUT of the over-the-center position. A spring? A lever?
Compare the actual rear frame with the original CAD. Hmmm. Something significant changed along the way. See the red axel tube on the CAD? It is at about a 60 degree angle to vertical. The actual Morph III has it almost vertical. Also note that the CAD design of Morph III (From Graham Butler) shows a tight 39.4" wheelbase. The actual Morph came in at about five inches more than that. Hmmm again. That's a lot!
Front end steering interference with legs (imagine they are there.
Wheel at 90 degrees.
Morph II seat height.
Morph II seat height is 16.75 inches. Almost four inches higher than Morph III.
Morph II seat height at front is 19"
Seat base to pedal center.
Seat base to pedal center is 25". Two inches more than on Morph III.
Morph II Seat back to pedal center - 23"
Morph II wheelbase.
Morph II wheelbase is about 58"
This matches the CAD. However, note the 5" trail shown above. That was too high, and we eliminated it by adding a tab to drop the lower fork.
Morph II low rider head tube angle.
Morph II low rider head tube angle is 36.3 degrees. This is higher than the CAD because the rear frame seat angle is not all the way down.
Morph II low rider trail.
Morph II low rider trail is about 1.5" positive. It rides very well
Morph II turning leg clearance: good.
Morph II turning - note that footrests hit the ground before you can turn 90 degrees.
Morph II high rider seat height.
Morph II high rider seat heigh is about 27.5 inches.
Front seat height is 27". Slight downward tilt.
This matches the CAD design. Note that the trail is almost zero.
Morph II high rider head tube angle.
Morph II high rider head tube angle: 52.3 degrees. A bit higher than the CAD, but again the rear seat angle adjustment isn't all the way down, as it is in the CAD drawings.
Morph II high rider trail.
Morph II high rider trail: about .5" negative. (Not bad!)