There are a few factors that can be different from one cycle to another:
1. Wheel size. If you are used to a certain size, you expect your cycle
to go a specific amount of distance with each pedal or idle. This is most
noticeable when you need a quick balance correction. In this area, back in
1983, it took me a whole year to get comfortable doing Freestyle on a 20"
wheel instead of the 24" that I was used to.
2. Crank arm length. This will make your feet feel akward, because
they'll be making different sized circles. This type of thing is less
noticeable on a bicycle, because all pedaling sends you forward, and there is
no other balance control provided through the feet.
3. Gearing. If the giraffe is geared up or down in any way, it's the
same as switching to another wheel size.
4. Tire pressure. High pressure makes the cycle very "turny" and
"spinny" (look those words up!). If you suddenly switch to one that's in
need of air, there will be much resistance each time you make turns or
balance corrections.
5. It's all in your mind. Hey, it could be.
Anyway, with time and practice, most of this problem will fade away, and your
brain will be able to switch from one familiar cycle to another very quickly.
Now for the ultimate challenge, try switching from a 20" with 5" crank arms
to my 45" big wheel, with 6 1/2" crank arms!
John Foss, President
International Unicycling Federation
unifoss@cerfnet.com