Urban Motorsports and the 5 Turn Track

 There is some urban motorsports going on...

Of course there is simple car drag racing that simply tests acceleration of
two cars side-by-side with end of run speeds likely under 80 mph

And sport bikes (motorcycles that could be raced with just a few
modifications) are going hard acceleration and very high speed on city
interstate highways. Often the police just tail along behind with blue
lights off because there are a lot of high speed fatal crashes...

Now very high speed is not fundamental to racing. It's vehicle control that
is fundametnal to racing. Vehicle control that is practiced at 30 to 50 mph
applies to vehicle control at higher speeds. And all racers have first
learned or practiced vehicle control at 30 to 50 mph before going on to more
serious situations...

Of course now we need a track...

But amateur sports car racing is available, club motorcycle racing is
available, and racing schools are available.

So we might not need a metro track that is simply available to the
public...but consider the idea. But we certainly need a metro track that is
available at low cost to sanctioning bodies.

Well consider the 3/8 mile paved oval. The 3/8 mile oval is not that
significant because the wide line out of the corner is just about the
turn-in to the next corner. It likes going around in a big circle in a big
traffic jam. But it's hard in the corner and makes it's point. Often they
are called bowls...

Then the 5/8 mile paved oval is truely significant. A 4-cyclinder midget
race car would exit onto the straight out of the corner at about 110 mph,
hit 130 mph at the end of the straight, back off and turn in to the next
corner at about 110 mph, have a mid corner speed of about 90 mph, and then
exit onto the next straight at about 110 mph. Got the pattern ? Well it's
more than a pattern it's real world difficult endeavor in a rock hard
world...

Of course the 5/8 mile paved oval is often in the actual metro...in metros
that are actually motorsports oriented.

And now you get it that the 1 mile paved oval is very significant. Actually
the 1 mile clay oval is also very significant...

But how about a sports car track (called road courses) that is not much
bigger than the 5/8 mile oval...and thus very metro-like.

Sure I often draw a five turn road course. (Now oval racers call a 180
degree turn as two turns while sports car racers call it one turn.)  And the
following five turn road course is a little different from the ones that I
usually draw but every mathematical detail is worked out for this example:

First there is a 1015.9' straight, then a 90 degree 200' radius curve to the
right, next a 300' straight, then a 70 degree 214.22' radius curve to the
right, next a 300' straight, then a 90 degree 150' radius curve to the
right, next a 290.85' straight, then a 70 degree 214.22' radius curve to the
left, next a 300' straight, and finally a 180 degree 150' radius curve to
the right.

And the total length of this track is 3,751.21 feet or about 0.71 miles...

Of course a 4-cylinder midget race car (open-wheel single-seat roll-cage
car) could race on this track if the cars were not set up only for left hand
ovals. And SCCA SSB race cars (showroom stock with roll cages and optional
suspensions) could race very well on this track. Finally motorcycle sport
bikes could race or run on this track although the straight might be a too
long for the powerful motorcycles...and in that case a chicane is often
added half way down the straight

 
The problem for bikes is not the course layout, but lack of run-off.
You can make that straight as long as you want, but you gotta have a
decent amount of gravel or paved open space at the end of it.  This is
different from what cars need.  The smaller you make the track, the
greater is the percentile disparity between how much space bikes and
cars require.  A 0.72 mile track is not very fun for modern
sportbikes.  It would probably work much better as a supermoto track,
provided sufficient runoff.

 First there is a 1015.9' straight, then a 90 degree 200' radius curve to the
right, next a 300' straight, then a 70 degree 214.22' radius curve to the
right, next a 300' straight, then a 90 degree 150' radius curve to the
right, next a 290.85' straight, then a 70 degree 214.22' radius curve to the
left, next a 300' straight, and finally a 180 degree 150' radius curve to
the right.

And the total length of this track is 3,751.21 feet or about 0.71 miles...


Sure but tracks don't have much run-off area at the end of the straight. And
that leads to a design of a fast turn at the end of the straight rather than
a slow turn at the end of the straight. But both designs are popular...with
the first design there is a fast turn to catch the speed and with the second
design there is a slow turn to make the end of the straight obvious.

But this five turn road course could be laid out in a parking lot and be a
faster and more practical course than a sports car slalom course. Then
there's run-off everywhere and the public could make runs one vehicle at a
time...

Or this five turn road course could be a permanent track that is affordable
to build...like the 5/8 mile oval.

And the point is a five-turn road course that is one mile or less in length.
So the shorter straights could be lengthened anywhere two turns rush
together too much.

But a 7/10 of a mile track is not much fun for a sportbike ? Well, turns 2,
2A, 3, and 4 at Sears Point are not high speed turns but are okay with sport
bikes...

 
I'm not sure what you mean by the above.  No matter what is at the end
of the straight, you have to have runoff.  If it's a kink in the
middle of it, like what's at Laguna Seca's T1, then it's most likely
not really a turn.  If a vehicle can be run through that section flat
out on a variety of lines, it doesn't require runoff.  But something
will follow that straight anyway, right?  So somewhere, there's gotta
be room for out-of-control bodies and machines to come to a stop.


People already do time trial styled parking lot racing with cars,
which is called autocross.  I think it's a really neat idea.  But it
won't work for bikes except for supermotards.  The reasons are two-
fold:

1. Parking lots of nearly impossible to clean from the numerous oils
and other chemicals that accumulate on them.  Cars are a lot more
tolerant of variations of traction midcorner than bikes, especially if
we care about safety.  Motards, with their light weight and lots of
suspension travel, could handle it, but if you try to run it with
400lb street bikes, everyone will leave after seeing the first 3
people dump it unexpectedly and do upward of $2000 of damage.

2. Gear.  People can run autocross in their shorts and T-shirts, so
long as they have helmets on.  Not sure if gloves are required.  You
don't need a roll cage, expensive race tires, or anything like that.
It goes back to the previous point but bikes don't recover nearly as
well from loss of traction.  There's no such thing as spinning out on
the bike -- you dump it.  So even if you build this thing in a city,
you'll have to make sure participants are geared up, with a lot of
emphasis on energy absorption (think motocross gear).  Also consider
the fact that most parking lots have a lot of lamp posts and other
immovable objects in place.


I like this better, but we basically already have this concept --
supermoto.  People thought it would bring moto racing to the masses,
and in some ways it has.  Dirtbikes are getting converted for street
use all over major cities, stock motard bikes are selling like hot
cakes, while other bike sales are in decline right now.  But we have
yet to see actual supermoto racing gain mass appeal.  Maybe my vantage
point is biased toward road racing, but for now all I see is addition
of motard-based classes to club racing schedules.


Put it this way, the fastest bikes at Loudon, which is a 1.6 mi road
course, are 600's, followed closely by SV650's.  That track feels
incredibly cramped to me on a 2001 CBR600 F4i.  In 2004, I raced at
Las Vegas Classic Course, which is also very small.  I was on a built
EX500 -- that bike suited the track pretty well.  That's the only kind
of street bike (plus maybe SV and Ninja 650) that will feel good
racing on a track half that size, and most people with those bikes on
the street in this country, are not gonna be looking to race, whereas
all the squids will flock with their 600's and 1000's, only to dump
them or be disappointed by getting beat by one or two people smart
enough to bring their motards to the fight.  I wish this could work,
but that style of racing just doesn't work for bikes in my opinion.
What could be really fun though is if you did this for scooters...

 
Tracks don't have very much run-off at the end of the straight. The racer is
expected to turn into the corner. (If you go straight at the end of the back
straight at Palm Beach you hit a guardrail and flip into a lake.)

But I didn't say in the first place that we were advocating tracks without
run-off. I just accepted it as mention of a design fundamental...


No, I designed a course that is faster and more practical than sports car
slaloms. But also the transitions from straight to corner are relatively
easy except for the corner at the end of the straight. In that way it's
smilar to Sears Point turns 2, 2A, 3, and 4. Then the straight and turn-one
are similar to a 5/8 mile oval...



I'm not advocating a proof-of-concept...

I'm advocating a public policy of cities or municipalities building or
supporting minor tracks...

Rather than advocate a 5/8 mile oval I advocate a 5-turn road course...or
put a 50' foot straight in the 180 degree turn and make it a 6-turn road
course.