From: Performance Bike Magazine Article
Thunderace not handling as well as you think it
should? All the boys on the latest bikes
having to wait for you at every roundabout? If you spend
all your time in the Little Chef nappy
changing area when you're out on a breakfast run
listen-up Thunderace kids.
Help is at hand... Thunderaces are heavy old chaps by
today's slimline standards, but they
can still just about cut it with the best of the new
kids on your block if you set them up properly.
The bike we are using has a pretty representative
14,500 miles on it and is in good nick.
We gave the bike a general look over before naffing
off to Donington Park for a track day
Mission: to get in the way the experts while finding
the required settings to make the Thunderace
a sweeter handler. We put all the suspension
adjustment back to the stock positions and took it
out for some tentative laps. And tentative they were
-just bouncing the front end while the bike was
stationery made you feel sick. It mayas well not have
any suspension damping at all.
It didn't take us long to find the standard setup's
limits. The bike was wallowing badly through
Schwantz Curve Gust after the Old Hairpin) and dragging
its hero blobs almost everywhere.
It lacked feel at both ends and turned-in like a
Harley Fat Boy. Mid-corner it was a handful too:
All it took was a breath on the throttle and the rear
would squat, unweighting the front tyre and
letting the bike plough to the outside of corners.
It's a shame really, because the engine is a joy and
the frame as strong as an ox. Back in the pits, we
noticed the tyres were looking really
battle-scarred, even though they'd only done ten laps.
They where ripping away in chunks, a clear
sign the tyre was being overworked by badly set-up
suspension.
We started the treatment by adding two steps of spring
preload to the rear shock, and upped the
compression four clicks while the rebound was upped
three clicks. The tie-wrap we always attach
to the forks to indicate the travel used had buried
itself in the yoke, so we knew all the travel
was being used. The forks got similar treatment to the
shock. We turned the spring preload
adjusters in another ring, the compression was upped
five clicks and the rebound damping
got six clicks added. The hero blobs came off and we
went out for another session.
The bike now, at least, looked like it wasn't a fish
out of water We managed to pass a few people
and got the tyres up to a respectable temperature
without ripping the hell out of them.
The YZF wasn't decking out quite as much now, but we
noticed the aluminium end-can had touched
down in a couple of places.
There were complaints the bike took a lot of time to settle
after you turned it into a corner and
someone mumbled: " Man, this thing doesn't let me
know what it's doing. I'm not sure if the front
is tucking or sticking as the bike turns. It sort of
floats." Translated, this means it lacks feedback.
So, we added more compression damping front and back
to hopefully stop the floating feeling.
We added a step on the rear spring and hoped that it
would be enough as the there was only
one position left to use.
Back on track, the bike was reborn. It was hooking up and
going good enough that a couple
of the R1 track-type geezers had to come up to check
what we were doing.
They were quite upset that we'd managed to run around
the outside of them at Maclean's and
then hold them off down the straight all the way to
the braking point (Oh Pete, you're such a hero -ed).
And brake the Thunderace does. It was the first bike
to get the Sumitomo calipers that have graced
Yamaha's sportsbike range ever since. They are among
the best out there and, although we noted
some fade, they still had the power to get the big Yam
stopped lap in, lap out.
On the road, the track settings where a bit harsh on
the arse but the bike turned so much better
that we found ourselves putting up with it. The
Thunderace might not be the choice of
steed for, say, a Superstock race, but with careful
tweaking you'll never be last to the Little Thief.
Oh yeah, and it'll do all that two-up sports touring
stuff too if you really want it to
The Thunderace has a torquey, bullet-proof motor that
will top 165mph on a good day. It benefits
from a jetting kit, end-can
and a day on the dyno to sort out the fuelling. But don't forget
it has the patented EX UP
exhaust valve (and only five gears,so the ratios are well-spaced)
so don't replace it with a full
system that does away with the thing.
EX UP uses a butterfly valve in the collector pipe
that alters back pressure and gives
more bottom end power while not robbing the upper rev
range of its peak power prowess.

1
First step is to get it on with some rear
preload. We ended up one step off max
leaving 5mm of static sag

2 Rear rebound damping is
dialled to within
three clicks of max -three up from where we started fiddling
with it

3 Four clicks
added at the easy-to-get-at rear
compression adjuster. The final setting was
within two clicks of maximum

4
The front end was super-soft to
start with,
burying the stanchions into the sliders. 30mm
of static sag, had things moving in the...

5
...right direction. This was
achieved by winding the preload
adjusters
in until just two of the indicator rings were showing

6
Upping compression
damping slows the rate
of the fork dive. Peter, the one who interferes with
toothy rodents, settled on four...

7 ...clicks off max. When it came to rebound damping, PB's very
own caribou-shagger
was happy at seven clicks from max

8
Get a spod to lift the bike's arse and measure between
a fixed point
at the spindle and one on the tailpiece

9
Now let the bike settle and re-measure.
The measured difference is your 'static sag'.
In this case it is merely 5mm

10
If you do any major tampering with rear ride height,
make sure you check the chain is still tensioned
correctly afterwards

11
You'll be
wasting your time if you try to get your bike handing
all proper
like with the Wrong pressures in them there black things

12
The end
result of Moose Boy's endeavors.
Nice even effects, but could be a bit cleaner -just like his DVDs

YZF1000R Suspension Baseline Settings:
FRONT
Static
Sag: 30 mm
Compression: 5 clicks off of max
Rebound: 7 clicks off of max
Preload: 2 lines showing
Tyre
Pressure: 33 psi (track)
35psi (road)
REAR
Static
Sag: 5 mm
Compression: 2
clicks off of max
Rebound: 3
clicks off of max
Tyre Pressure: 35
psi (track) 37 psi (road)