Tire Selection For Track Conditions - Honda CRF250X 2006 Owner's Manual & Competition Handbook

Choosing the correct tire tread pattern and rubber
compound can affect your placing in competition.
The tires on your motorcycle offer a "happy
medium" for the variety of soil conditions the
majority of riders are likely to encounter.
Experienced competitors often switch to tires
developed for specific terrain conditions. If you
do switch, stay with the factory recommended
sizes. Other tires may affect handling or
acceleration.
Be aware that tire sizes (width and aspect ratio)
do vary from manufacturer to manufacturer or
even among tires made by the same
manufacturer. Variations in tires, especially the
sidewall profile, can change the attitude of your
motorcycle and its handling. Tire variations that
raise or lower the rear of your motorcycle have a
more significant effect on handling than
variations in front tires which, generally, don't
vary as much. Often, you can see or feel the
change in tire size. Another way to check is to
measure the rolling circumference of the old and
new tires. A higher profile tire will have a larger
rolling circumference.
If you do switch to tires designed for special
terrain use, remember they will be less
acceptable in other circumstances. For example,
an aggressive mud tire will give excellent grip on
wet, loamy terrain, but less impressive grip on a
hard surface.
If you choose a tire with a sticky compound for
added traction, remember that it may transfer
additional loads to the transmission because it
grips so well, especially when riding in situations
that normally place unusual demands on the
transmission.
Complete consumer information can be obtained
from the various tire manufacturer
representatives and dealers.
Some general recommendations for specific
terrain follow:
Hard, Slick Soil
Use tires with many relatively short knobs that
are close together in order to obtain the largest
possible contact patch on the surface. The rubber
compound needs to be softer for hard ground in
order to hook up, but not so soft that the knobs
roll over easily and affect holding a straight line.
These tires tend to wear more quickly than
standard tires because of the combination of soft
rubber and hard terrain.
Muddy Soil
Use a more open tread pattern to avoid clogging.
For these conditions, the relatively long knobs
will probably be made from a harder rubber
compound to reduce any tendency to bend back
under acceleration or wear quickly.
Loose, Sandy Soil
Use a tire that is similar in construction to those
needed for tacky soil and mud, but with a few
more knobs.

Tire Selection for Track Conditions

Adjustments for Competition
135