UPGRADE 1970'S BIKES

On Oct 7, 7:18*pm, Jay Beattie wrote:
On Oct 7, 6:22*pm, Dan O wrote:









On Oct 7, 2:15 pm, Joe Riel wrote:

Frank Krygowski writes:
On Oct 7, 1:59 am, Joe Riel wrote:
Dan O writes:
On Oct 6, 4:09 pm, Frank Krygowski wrote:
On Oct 6, 3:01 pm, Jay Beattie wrote:

On Oct 6, 10:53 am, Frank Krygowski wrote:

I usually have my straps set at a sort of compromise length, loose
enough to flip into very quickly, but tight enough to provide just a
bit of security against foot slips. *They're tight enough that I can
bunny hop, which is good enough for me.

Based on all the trick riding I see, you don't need to be clipped in
to bunny hop the bike -- but I find it hard to do on a road bike
without clips, so I must be a flounder...

I just tried it, to be sure of my memory. *As I thought, I can get the
rear wheel up just a little, maybe a couple inches, on a bike without
clips. *That's my retro 3 speed. *I seem to be pushing a bit rearward
on the pedals to do it, which seems to be the same thing I see in
videos likehttp://www.youtube.com/watch?v=Z19zFlPah-o

Look at ~2:00. See how his weight goes way back to lift the front end,
then, springing off the pedals, he leaps into the air, chasing the
front end with his body mass, until the handlebars are in his lap.
The rear wheel is still on the ground. *Then he fluidly but
instantaneously transfers his body's inertia to the bike via the
handlebars. *See how his elbows and knees - fully extended a fraction
of a second before - are bent at the top and the bike has come up
underneath him? *There's no lifting it by the pedals.

I don't know if I've really got it figured out, but for me I think
it's almost all through the handlebars.

An impulsive force applied to the handlebars and in a direction directly
away from the center of mass of the bike will do the trick. *To verify
that, stand in front of the bike and apply such an impulse; both wheels
will leave the ground simultaneously. *Alas, applying the same impulsive
force while riding the bike is quite awkward (try it, you'll see). *The
way I believe it is done is in two steps: an upward pull, then a forward
push. *Those can be efficiently applied and since the average direction
of the two force is through the CoM the result is nearly the same.

That sounds like a possibility to me. *However, when I do it on a flat
pedal bike, I certainly get the impression my feet are pushing a bit
backward on the pedals, and sort of trying to claw them upward, with
my toes pointed downward. *I'm trying to understand that sensation.