Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/127847
F
IR5TRIDE Laverda 7505
36
you get hard on the gab and rev the
Laverda up high , this is a potent recipe
for fun biking th e It alian w a y enh anced acceleration compared to prev iou s La ve r d as, a pretty punchy
midrange from 4000 revs upward, and a
fast -forward view of the world around
yoo above 6500 rpm, all accompanied
by what is nowadays one of the most
distinctive engine notes in the business
now that 90-degree V-twins are commonplace and even Yamaha's TRX 850
tries to pretend she's a Vdue, not a
slan t-twi n, with her 270-degree crank
throw.
The 180-degree fo rmat (one pi s ton
up, on e d own) of La ve rd a' s parallel tw in motor gives a harsh drone that
rasp" invigoratingly beneath you as yo u
twist the wri st , the crisp response of the
EFI butterfly throttl e and all-new engine
mapping deli vering great mid range
pickup.
You don't have to use the gearbox as
hard as on a 748 Ducati to get performan ce , though there' s a Iittle more
vibration on the 7505 than on the Ducati
or on previous Laverda twins, in spite of
the single gear-d riven counterbalancer.
This isn't really in tru sive, just no tice able, and only come. at you through the
footres ts and not through the handl ebars, w hic h have bala nce weigh ts o n
th eir ends that dial the vibes oot completely.
Strangely, the foo tpeg tingles only
occur u nder load, and so aren't a function of revs, more of throttle opening.
Accelerate hard a t 4000 rpm and yo u
fee l the vibes - bu t back off the gas at
seven gra nd-plus in fifth gear and they
disappear . Maybe a func tion of the
revised balance factor for the plain-bearing crank in 750cc gu ise?
With a top speed of 148 m ph reached
in Italia n govern ment homologation
tes ts, th e 750S certa inly delivers the
goods performancewise, as well as fulfilling Tognon's brief to look forward
yet keep an eye on the past.
Laverda tech nical boss Nicola Materazzi, th e former Ferrari, La mborghin i
and Cagiva GP race engineer heading up
th e R&D team responsible for the new
engi ne, explains: "Ou r objective was to
repl ace the 668 air-cooled design , w hich
had reached the end of its development
life, wit h a new engi ne derived from it,
which met the dem ands of the market in
the 21st cen tury but cou ld be put into
production relatively qu ickl y," Materazzi says. "It had to be a 750, an d a parallel-tw in, to build on Laverda's histori-
(Above) The IIquld-cooled 747cc vertical twin is the IIrst new eng ine to
be prod uced by Laverda since the company was take n over by Itali an
indu st rialist Francesco Tognon. Output is 80 bhp at the rear wheel.
(Right ) Paioll supplies the suspension for the 750 5. and t he pieces
continue the com pany' s new trad it io n of solid performance.
cal links with su ch mod els - just as a
Ducati must be a 9Q-degree V-twin, so a
Laverd a must be a parallel-twin. 50 the
idea was to create som ething quite new
based on the concept of the o ld - but
with absolutely modem performance .
Th1t'S wh y we've retained only about 10
perc ent of the old 668 engi ne - mainl y
th e s ide covers, the basic cr a n kcase
design and some parts of the crankshaft.
Bu t th e rest of the en gine is all ne w,
including the cylinder head, camshafts,
valves, cy li nde r s, co n rod s, gea r box
rati os, etc., etc. It's really' a new engine,
and with an absolutely innovative cool ing system derived fro m Formula 1 car
principles, which we ha ve , however,
pa tented for motorcycle application."
This system sees the coolant leaving
the radiator and entering the eng ine at
the cylin ders before exiting at the cylinder head, rather th an th e o the r way
around, whi ch is more usua l. This, says
Ma tcraz zi, delivers improved ther mod yn am ics and more constant cooling :
Read his patent applicat ion if yOll want
to know how or why!
Not on ly is th e new liquid-co ol ed
eng ine much sm aller than the air-cooled
one eve ryw he re except in cra n kcase
wid th , it's also fa r ligh ter , scali ng 128
po unds against the old motor's 154.
Tha t in itself would be sure to have
an effect on perfo r ma nce - es pecially
acceleration and braking - even wi tho ut
the increase in capacity and po wer outpot. But it' s wh ere the weight has been
saved that has the most noticeabl e spinoff benefit: ha ndling. The 7505 chassis is
the same tw in-s pa r a lloy frame as is
u sed on the 650/668 , but, th ough this
always set the class sta nda rd for middleweight sportbik es , it's even more
nimb le tha n befo re in 750 form , bu t with
added stability. This unlikely reconcil iation of two opposites is achieved by (a)
th e lig hter 429-pound all-up weight,
with the 5-gallon fue l tank fuell ed right
up (still with the sa me quirky locatio n
for the filler - under the passenger sea t),
and (b) the su bstantially lower cent er of
gravity co mpared to the old engine.
This comes a bo u t b ecause o f the
huge w eight savings deliver ed by the
li q ui d-coole d en gine' s much smaller
cylinder head, which, with a flatt er 29.5degree total included valve angle for the
30mm inlel/27mm exhaust valve.