The
Yamaha versus TVS(-Suzuki) rivalry on the Sholavaram and Sriperumbudur
race circuits has enthralled diehard motorcycle fanatics no end for
many years. And here we were trying out the top spec racers in an
unprecedented head-to-head comparo on the same day with the top guys
from both teams wrenching for Team OVERDRIVE.
One thing must be mentioned here at this juncture itself and that
is the Yamaha racing effort and successes, have much to do with the
privateers themselves with Escorts and Yamaha having no clue whatsoever
about the racing game in the country. It was left to the tuners of
the calibre of Raja and Raju, Noshir Irani, the brothers Bhathena
- Sohrab, Sheri and Aspi, to name the most important of them all,
to extricate meaningful power and harness it all into a winning combination.
What helped them all nevertheless was the fact that the reed-valved,
seven-port torque induction motor was a super design and could take
any amount of modifications. The Yamaha motor had already distinguished
itself in many other markets and certain go-faster bits were always
available and these made life a bit easier for our resident Indian
race bike constructors.
In comparison, the Suzuki AX100-based bikes were always struggling
to compete on equal terms with the RX100 Yamahas in stock trim. Thanks
to the corporate decision (initiated by TVS head honcho Venu Srinivasan)
to go racing to first learn and then to incorporate the results from
that effort onto the production bikes meant that a dedicated effort
was the only way to succeed against the overtly superior RX100. But
credit TVS for plugging away and coming up with innovative solutions
to try and win even while making lesser power but packing in tremendous
doses of reliability. Setting up a dedicated racing department at
Hosur with its own machining and fabrication facilities along with
a dedicated dyno for tuning and testing out the engine mods plus a
decent budget was a visionary achievement in Indian motorcycle racing
and it has paid handsome dividends. The Shaolin was the result of
the lessons learnt in racing with the Supra SS and Shoguns and not
many companies can boast about such a feat.
All the bikes for our group test were built to the FMSCI's Gp C specs
where frames have to be standard and could only be strengthened with
none of the imported monoshock suspension jobs being allowed as on
the previous full blown Gp D bikes. Engine mods were permitted as
long as they were all done in India and the main bit which was free
for the engine was the use of imported carburettors.
We got our track test underway with the all-white Yamaha RX135 first.
The large OVERDRIVE sticker helped to relieve the blank expanse on
the fairing and one shouldn't read too much into it. The hallmark
of this bike is its light weight and great handling and Aspi was straightaway
on the pace. A couple of laps later he came in and said that the bike
was way too overgeared for his liking, Raja, Raju and yours truly
burst into laughter for we had just finished discussing this as he
pulled in.
The Sriperumbudur circuit is one which calls for torquey power but
the RX135 was built for the expert rider (Raju and Raja) who could
play in a narrower power band and go on to set fast lap times. Thanks
to modifications to the head (enhanced compression ratio), induction
system (bigger reeds and a larger 34mm carburettor), revised ignition
timing and a specially designed expansion chamber, Raju's RX135 begins
making serious power from 6500rpm before peaking at 10,500 revs. The
trick was to keep the bike in this narrow power band because anything
below 6500rpm and a bicycle would get by in the corners!
Overgeared
the RX135 might have been (set up as it was for the 64kg Dwarak Leelaram
who rides this bike on and off) but Aspi did find out that from gear
to gear she had more thrust on offer than the Shaolin he rode later.
Another area where he felt the RX135 could have gone even quicker
was if it had been equipped with a front disc brake. The 130mm dia
front drum was hopelessly inadequate in trying to haul the bike down
from speed, Aspi having to brake earlier and harder which obviously
shaded it somewhat in the lap times. But on sheer top speed it was
on par with the Shaolin.
The Sriperumbudur race track is one where peak power is not just the
ingredient needed to excel on. Thanks to the tight 18-corner circuit,
the quickest section of the track is when the rider exits flat out
from the D-section at the far end of the track and accelerates away
into the next corner and onto the Castrol straight where he gets a
chance to shift into fifth. Fifth is incidentally available only at
three sections on the race circuit and I am obviously saying this
in relation to the power developed by a Gp C 150cc machine.
It is no wonder Raju was so strong on the RX135 when he was racing
for with his 60kg bulk and the bike's 75kg, the package was awesome
and successful. In anyone else's hand the bike never did well because
of the peaky power delivery.
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