Benelli 504 Sport
Benelli 504 Sport
. .Rumour holds that the old Honda CB500 four enginewill fit straight into the Benelli 504's chassis. I don't know how true this isdespite having owned a CB500 a long time ago. The engines do look similar andtheir power output is equally bland. The 500cc OHC across the frame four claims50 horses but its delivery is so linear that it seems a lot less, there's neverthe feel of a motor coming on cam. Just like the old Honda, it'll put 80 to85mph on the clock without any undue abuse, but going any faster is such hardwork it's really not worth the bother.
The engine responded to juvenile tacho excess byneeding valve adjustments every 500 to 750 miles and putting out a flurry ofsecondary vibes through not just the pegs and bars but also the seat and tank.The carbs kept their balance for about 500 miles and every now and again one ofthe slides stuck, which made the engine hunt between 1000 and 5000 revs!
Carburation always seemed slightly hesitant, adistinct delay between whacking open the throttle and the back wheel doingsomething. Its relatively primitive nature showed up in fuel that was neverbetter than 40mpg. The dynamics of carburation, exhaust and combustion chambershape were shown up when riding the 504 into a strong headwind; speed was downto 70mph and fuel up to 35mpg!
The motor always felt revvy as well, I was oftentrying to change up another gear when I was already in top. I could neverpersuade the Benelli to adopt a relaxed pace to match the parameters of itsperformance and chassis. The gearbox, with more than 15000 miles done, wasneither slick nor precise; it mirrored, in fact, some old sixties Honda hack inits application. It was not impossible to adapt to, but even then would serve upa false neutral, which buzzed the motor like its poor old heart was going toexplode into a million pieces.
The double cradle loop frame could have beenproduced by any factory anywhere in the world, but was well enough thought outto save the bike even when it was slung into desperate conditions by a suddenfalse neutral. The whole beast was held in check by famously stiff Italiansuspension at both ends. The forks, despite their mileage still suffered fromsome seizing and responded to slow speed holes by sending concentrated joltsstraight up my arms. The shocks did the same trick to my spine.
Smooth roads held no terrors for the Benelli, itcould be slung over on to the stand prongs without the Pirelli tyres giving amoment's worry. The 504 had 425lbs of mass and slow steering geometry against itin the curves, but its stability and neutrality allowed me to take outrageousrisks when I was in the mood.
This stability held it in good stead on bumpyroads. The rider took a battering but the wheels held on to their line in a waythat the old Honda four could never hope to emulate - it used to waddle about onsoft suspension, zig-zaging from bump to bump. As the Benelli never acceleratedhard nor went very fast, any test of the chassis was limited but, apart from thelack of bump absorption, I was at ease with the 504.
Which is more than can be said for the drivechain. It always wanted to dissociate itself from the chassis, wore at anastonishing rate and broke three times when I tried to run them after removinglinks. They barely lasted 4000 miles. One time the broken chain busted into theback of the crankcases but I repaired that in-situ with good old Plastic Metal.
The only other chassis horror was the waycorrosion would suddenly appear from nowhere, spread like wildfire until thewhole component was covered in gunge. The frame, wheels and exhaust wereparticularly susceptible. The front disc calipers followed the trend set by theJapanese of seizing up over the winter, but they were easily rebuilt. Padslasted 8 to 10,000 miles a set.
After a year's riding, various electricalcomponents decided they couldn't take extended exposure to the English weather.Switches that filled with water, corroding contacts, made for amusing incidentssuch as the indicators flicking on and off in a psychedelic manner whilst thehorn, normally nothing more than a croak, blared harshly enough to havepedestrians waving their fists in anger. The fuses either rusted to death, fellout or exploded.
By the time I was able to find the energy torewire the bike, the generator was burnt out, the rectifier had melted, thebattery was devoid of acid and just about every other electrical component hadto be replaced. The breakers provided a viable source of electrical components,although I stayed clear of Suzuki bits. The most difficult part was persuadingsomeone to rewind the generator but fifty notes in the right hands solved thatone.
As the bike had to be stripped of all its cycleparts to access the electrical bits I took the time to rust proof and thenHammerite the frame. Some Scientific Coating's clear liquid was put on polishedwheels, which meant that rather than a two hour cleaning session a week a quickwipe with a rag was all that was needed to keep them neat. A Honda CB500/4 fourinto one exhaust (thirty notes secondhand) was persuaded on to the Benelliengine but needed a bit of a pounding to clear the lower frame rails. It soundslovely, but didn't increase performance.
Other complaints that could be levelled at theBenelli included a pathetic seat that went hard after 50 miles, wheels bearingsthat needed replacing every 6000 miles and a petrol tank that even when newishloved to rust rapidly - I'm on my third, one of them actually dropped a load offuel over the engine. The bike sizzled for a while but resisted the urge toexplode.
The Benelli was quite resistant to crash damage,as long as engine bars protected the ends of the crankshaft, the demise ofeither extremely expensive. I've slid off on diesel a couple of times, did nomore damage than batter the pegs and bars. More serious was smacking into theside of a car that shot out of a road so fast it could only have done so withthe sole intention of trying to kill me.
The front end hit the car, the sudden loss ofmomentum causing me to somersault over the cage, roll down the road a few yardsand then pick myself up. I was full of craziness by then and would've torn thedriver limb from limb, but the impact of the crash had warped the car's body sothat none of the doors would open. There was a strong smell of petrol, so Itried to pull the Benelli out of the car with the intention of throwing alighted match on the cage once we were at a safe distance.
Fortunately for the cager, there was no way Icould pull the bike out. Someone had phoned the police so there was no hope ofphysical retribution. When the bike was finally pulled free, damage consisted ofbent forks and dented exhaust, along with a bit of cosmetic damage. The castfront wheel was still intact. His car looked a write-off so I decided not toinform my insurance company which would stop his claim dead.
I had the forks straightened for £30 and cut andwelded the pipes - they look a bit naff but matt black paint hides most of thedamage. The smashed clock was glued back together with Superglue, as was one ofthe indicator lenses. This may sound dodgy but I've found it works fine frompast experience.
This crash occurred about three years and 12000miles into my ownership (the clock read 19,650 miles). The only result of thedamage was fork seals that didn't last for more than 5000 miles (I hadn't had toreplace them before). There was so little suspension movement that the lack ofdamping that resulted wasn't too noticeable.
Handling became more alarming when the rearshocks lost all their damping (at about 23000 miles). The back wheel would tryto career off the road whenever I leant the bike over more than a few degrees onbumpy roads. It'll also jerk around after hitting a pot-hole. That was easilysorted with a pair of rather more compliant Konis. My spine was thankful for thediminution in violence of the bumps that got through the chassis. A slight weaveoccurred at 90mph, but this speed was never sustained for more than a fewseconds so the weave had no chance of developing into a wobble.
A cheap rack and massive top-box were added for awhile, but that did upset the handling whenever any kind of mass was put in thebox. It didn't feel safe above 60mph. One blustery day, the wind shook the backend so much I thought the swinging arm bearings were shot, but it was just thegale catching the plastic. In the end I dumped the top-box.
That didn't help the touring ability. The shapeof the tank meant that tank-bags slithered around all over the place, usuallyending held in place by nothing more than its own weight and my knees. The onlysafe place to carry luggage was on the pillion perch. Once I had a bungee cordsnap, wrap around the rear wheel whilst my clothes were scattered half a miledown the road. I never knew that bungee cords could be stretched so thin.
Touring the bike could manage, but only 150 to200 miles a day. Any more then it became very uncomfortable and somewhatenervating (from the vibes and revvy nature of the engine). Fuel, enginemaintenance and chain wear were other variables that didn't inspire during longdistance usage but the basic reliability of the engine meant I had everyconfidence in reaching my destination.
Some Benelli motors don't last very long (I'vejust brought a dead 504 with only 14000 on the clock) but mine has now done33000 miles without any major problems except for frequent doses of tenderloving care. I suspect that is the determining factor in durability, neglectedbikes both rusting and seizing quicker than most. Spares are so rare that itpays to track down one of the non-runners. Rarity of the 504 makes that hardwork.
Prices are hard to work out. There's always theodd jerk who thinks because it's rare and Italian it must be a classic worththousands, but I bought my nice one for £450 and the non-runner for £95. Thatsounds about right for a machine that's slow, quick corrode and heavy onconsumables. I like its looks but can't claim it approaches beauty. It runs wellin town, for short blasts in the country and for moderate touring. As a cheapand cheerful all-rounder it makes the grade, as a future classic my money's onthe CB500/4!
Source .umgweb.com
KAWASAKI Z500 BENELU504SPORTLAVERDA 500MONTJUICHALF-LITRE HEAVEN by Witch Bike magazine
No longer are the middleweight bikesthe low-life alternatives to the last decade's expansion into the litre-plusarena of high-performance machinery. John Nutting tests three five-hundredswhich for reasons of price, performance or appearance (or all three together)offer the discerning motorcyclist everything that could possibly be wanted in amachine. Photography by John Perkins and Ian Dobbie.
KAWASAKI Z500
It's not so long ago that Kawasakiowners were the constant butt of every joke under the sun about poor handling.But that's all changed with the introduction of the company's smallestmulti-cylinder four-stroke, the Z500.If the Z650 four was a hint that Kawasaki were really capable, given theopportunity, of offering finely-honed road bikes instead of wobbly straight-linehot rods, then the Z500 is the final confirmation.
But if you think that the littlestfour is just the six-fifty with all the major dimensions reduced then take acloser look. And find out the subtle details in the development of a sportingroadster for the eighties.
True, the concept of the Z500follows the theme found in most of the top-selling Japanese motorcycles of thelast few years — an across-the-frame in-line four-cylinder engine mounted in aduplex-cradle chassis. In fact, on paper you'd be hard pushed to detect themajor differences between the 497cc Kawasaki and the first of the smaller fours,Honda's CB500, introduced in late 1971. Both have similar power outputs,compression ratios, carburettor sizes, overall dimensions and dry weights.
But the closer look reveals the waysin which the motorcycle buyer has become more demanding in the intervening eightyears. And a brisk ride down a twisty lane is even more eye-opening.
The Z500 is an extremely compactmachine with a wheelbase of just under 55 inches and a dry weight of 4231b. Itfeels small, thanks mainly to a narrow 3.3 gallon fuel tank and tidy proportionsaround the side panels and footrests that allow the rider to place both feetflat on the ground at traffic stops.
The frame itself appearsconventional in that it has a large diameter backbone supporting the steeringhead. But it is substantially supported above the engine with massive gussetplates which effectively stiffen the front end of the structure. The front fork,a smaller version of the unit found on the shaft drive Z1000, appears also to beoverly strong with leading-axle sliders with big clamps for the front-wheelspindle. At the rear, the swinging arm pivots on four needle roller bearings.
The torsional stiffness of the frontfork is a real necessity when over seven inches of travel have been opted foralong with a steep Steering Head Angle of 64 degrees.Were it otherwise, the fork would flop around uncontrollably when at fulltravel. As it is, it imparts a perceptably high degree of stability in the Z500that puts it on a par with the best bikes on the road.
Some riders might argue that thesuspension is harsh, and that's certainly true although it's not because of thespring rates. Kawasaki have opted for an average 50 lb/in fork spring rate withminimal preload along with ideal 901b/in rear springs.Given a lack of stiction in the suspension plus a lighter front rate with morepreload this set-up would work very well, offering a good ride with steadinessin bends. But the ride feels stiff and is none too mitigated by the hard seat.
Fortunately, nothing is lost in theoverall handling. The steering is excellent, being neutral and light to controlwhether the bike is being weaved through dense traffic or carved through tightbends. The tyres used impart confidence, being a ribbed Dunlop Gold Seal frontmatched with a Japanese-made TT100 at the rear, though we'd doubt if these wouldbe much good when raced, in which role the Kawasaki most certainly will finditself.
Moreover, the Z500 feels much morestable when cranked over than the CB500 ever did. And when matched to thesintered-pad disc brakes now found on all the top Kawasaki's, you have a chassispackage that marks a new high for Japan.
Two thin 10.8 inch diameter discsare used at the front with floating calipers while the rear unit uses the samedisc but with a double piston caliper. Only criticism is of the excessive reachto the front brake handlebar lever.
In performance, the Z500's enginematches the chassis perfectly. Peaking at a claimed 52bhp at 9,000 rpm with thered line marked at 9,500 rpm, it easily urges the bike to almost 110 mph flatout and puts indicated cruising speeds of around 90 mph comfortably in the graspof the rider even when there's only small sections of open road to play with.
Much of the engine's excellent poweris derived from the use of double overhead camshafts and the four free-breathing22mm-choke Tekei carburettors. Like the Z650 and the old CB500, the four-throwcrank runs in plain bearings and drive is through a Morse-type chain and gearsto the wet clutch. Bore and stroke are the same as the Z250; 55 x 52.4 mm. Butnew is the use of another Morse-type chain with an automatic adjuster fordriving the camshafts.
Some of the surprising snap throttleresponse and startling acceleration is derived from the six-speed gearbox andwide ratios. Gear change action is slick and noiseless and the 'box retains theuseful neutral-finding dodge that stops you selecting second from bottom at astandstill.
Kawasaki appear to have selected thegear ratios with drag racing in mind for the reve drops between gears are assimilar all the way through the range instead of having a large gap betweenbottom and second and closing up the other ratios. In normal use though theengine is so flexible, pulling cleanly and usefully from as low as 1,000 rpm intop, that the lower ratios hardly ever get used.
At the test strip though the effectis obvious. The Z500 fires like a cannon from the gate to be easily thequickest-accelerating 500cc machine on the market getting to 60 mph in 6.5seconds.The tractability has advantages in fuel consumption too. The Z500 returned justover 52 mpg despite being thrashed giving at worst 175 miles on a tankful.
With no kickstart lever, it's justas well the self starter was reliable. The engine fires up cleanly and is helpedon cold mornings by the throttle-valve lifter incorporated into the chokemechanism. The clutch was annoying though. Like an old Triumph, it would stickafter being left overnight.Unfortunately, and to our surprise, the worst feature of the Z500 is vibration.When used as a sports bike in the twisties it's doubtful if you'd notice it, buton motorways the vibes above 5,000 rpm are enough to render the rear-viewmirrors useless.Otherwise, the Z500 is a great little bike, particularly since it's the only Japfour of its size, both in capacity and bulk.
BENELLI 504 SPORT
One thing is sure with the Benelli504 Sport; you could never mistake its intentions. It looks a sporting machineand in every facet of its character it acts like one. Which is a blessing forBenelli.For there's not much you could comfortably recommend in the standard version oftheir 500cc four. Since it is so very nearly a Honda four in the enginecompartment, the machine suffers all the ubiquity of a Japanese four with thequirkiness of an Italian machine.
But the 504 Sport displays style andflashiness rarely, if ever, found in Jap bikes. Finish is in a metallic blackpaint set off by striking gold cast-alloy wheels and a small Guzzi Le Mans.
And it's a small bike that begs tobe ridden fast. The power band is sharp and needs to be nursed along on thefive-speed gearbox. And it's not until you're cruising above an indicated 80mphthat the riding position feels at all comfortable.
Otherwise the 504 Sport can be very awkward if you're not prepared to suffer thedisadvantages of a super sporting motorcycle. At town speeds, the raised clip-onhandlebar makes the wrists ache and the shortness of the riding position tendsto be very cramped. Furthermore, the top lip of the screen obscures most of theinstrumentation. Not that it matters much; it's pretty inaccurate.
On top of that the bike feelssluggish unless you wring its neck, compared to the other two machines featuredhere. In fact, the Benelli is barely slower than the Kawasaki in a flat-outdash, mainly because of the wind-cheating riding position, with a top speed ofaround 108 mph. (We saw 115 mph once on a long downhill section of road.)Most of the problem is in the heaviness of the throttle return springs and theinflexibility of the engine. Both of these conspire to give the rider theimpression that the bike is dragging a dead weight behind it.
Once into its best area, that is,when the rev meter is hovering in the 6,000 to 9,000 region, the 504 perks upappreciably and the real meaning of Italian motorcycling rings true.Like the Honda engine that the Benelli was copied from, the 504 Sport's motor isan overhead camshaft four-cylinder unit with the crankshaft running in plainbearings. Like the Kawasaki too, it has a Morse-type primary drive to acountershaft in the bottom crank-case-half with a set of drive gears to theclutch. Gearbox is a five speeder, the change being effected via a linkage, andthe final drive is by a conventional Regina chain, unlike the Kawasaki's sealedroller chain.
There are few changes to the 504 tobring its power from the 47bhp of the 500LS to a sportier 49bhp at 8,900 rpm.Bore and stroke remain the same at 56 x 50.6mm, though the pistons pump thecompression up to 10.2 to 1 and the camshaft has more lift and overlap. Gearingis the same as the LS giving 5,900 rpm at 70mph.
Apart from the use of alloy wheelsand the interesting adoption of the Moto Guzzi linked braking system, there arefew changes to the chassis either. At speed the bike feels taut and stablethanks to a shallow Steering Head Angle and a low centre of gravity. But thesuspension is mismatched and that same front end geometry leads to a measure ofresistance when you're hauling the bike from lock to lock at speed through thetwisty bits.
The front fork is under-damped,leading to some choppiness over bumps, a feature that is in conflict with therear suspension which is undeniably hard. It could well do without this as theseat is similarly rock-like.
Not that this necessarily detractsfrom the enjoyment of the Benelli. The four-into-two exhaust emits a jubilantgrowl and the hand controls are slick and easy to use.But there are enough annoying aspects of the Benelli to make the £1,742 listprice only appealing to the true devotee. The connected braking system, in whichthe right-hand Brembo disc brake and the rear disc are operated by the footpedal, isn't as powerful as we'd like. With so much braking area on tap andpleasant experiences of the system on bigger Guzzis we'd be inclined to thinkthere was something wrong on the Benelli's.
Also there was much too much enginevibration getting through to the rider's feet. And neither was the bike veryeconomical with only 46.3 mpg overall.Detailing is poor. The switchgear could have been much easier to use and theenergy expended in designing the ignition cut-out switch operated by the propstand (a real necessity since you can't see the stand from the seat) could havebeen directed in this area.Let's say the Benelli is a bike for the Boulevard nights.
LAVERDA MONTJUIC
How do you transform an ordinarymotorcycle into a popular classic? Perhaps you refine it over a number of yearsto make it appeal to the widest possible number of potential buyers.If your name is Laverda you do the complete opposite. You convert your road bikeinto a successful production racer and offer replicas for sale.
The proof? The Laverda Montjuic hasbeen outselling the standard 500cc Alpino by three to one. And this is despitethe race-replica being the most expensive 500 on the market at a shocking£2,095.
But such is the appeal of asuper-sporting machine with a proven record in competition. And Laverda werealways aware of it since the lamented demise of the SFC, the production racerbased on the factory's now obsolete 750cc SF twin.Trouble was Laverda couldn't offer a production racer legally in most countriesbecause invariably, the extra performance came at the expense of a prohibitivelyloud exhaust. In Italy they got round this by offering 500cc racing twinsspecifically for a novice racing series.
The British Laverda importers havealways adopted a more cavalier approach. And no sooner did they prove thereliability of the basic eight-valve double overhead camshaft Alpino unit bypulling off an impressive one-two in the 500cc class in the 1978 Barcelona24-hour race at Montjuic Park than they realised that they were onto a winner inthe home market.
Furthermore they also realised thatif they could offer a high performance 500cc machine in road trim, it wouldqualify for the tight production racing regulations currently enforced in UKmeetings and beat the Yamahas previously dominating the class. They were rightand the Montjuic sales have boomed.
Competition record apart though it'snot difficult once you've ridden a Montjuic, to realise why the bike's soappealing. It's got the purposefulness of a BSA Gold Star and the style of theold SFC, which incidentally it can outperform comfortably.Yet apart from the obvious differences with the glass-fibre handlebar fairingand seat (both of which are added to the bike after it arrives in Britain fromthe factory as a naked, tuned Alpino), there are few changes.
The frame is stock and retains thesame Marzocchi suspension front and rear. The basic engine and six-speedtransmission are unaltered too. However, the pistons give a compression ratio of10.2 to 1 and the camshafts have revised timing with the effect that thecompression pressure is upped to 150 psi from 115 psi.
To cope with this the 32 mm chokedowndraft Dellorto carburettors are recalibrated and the air cleaner isdispensed with while a megaphone-type extractor exhaust system to suit the camsalso gives extra cornering clearance.
The extra cranking pressure has hadits effect and though the electric starter motor is retained and normally copeswith its job well, the battery is soon to be uprated to make it foolproof.The overall result of the tuning changes is to up the power considerably andraise the maximum power revs to between 9,200 and 9,500 rpm. Importer RogerSlater has yet to put one of the engines on a dynomometer and will no doubt saythat the engines make enough power to win the races they're after for publicity,but we'd confidently predict that it must be in the 55bhp region at the backwheel.
Few would argue with that sinceowners have been complaining that they are running over the factory-stipulatedrev limit of 9,500 rpm in top gear with the stock gearing of a 42 tooth rearsprocket - which gives 116 mph. Given the use of a 40-tooth sprocket the 125 mphthat Slater claims for his bikes should easily be in reach. After all, with a 38tooth sprocket in the Island this year their own bike was clocked at 129 mphthrough the Highlander and the 9,600 rpm that Peter Davies saw on the revcounter compares with the computed figures. What's more the bike went to 10,300rpm on the drop to Brandish. That's 139 mph. . .
In day-to-day use such headyperformance figures are neither here nor there. And anyway there's little chanceof proving them since Slater invariably uses the demo Montjuic as a spare forracing.So we tried a bike belonging to John Owen, one of Hexagon of Highgate's happycustomers. A far too brief ride was enough to confirm that the Montjuic isindeed bound for a pla e in the motorcycling histoiy books.
Laverdas have always been favouredfor their good handling but the Montjuicraises the standard to new heights. It feels low and small, not surprising sincethe racing-style seat measures barely 30 inches from the ground. The handlebaris the same adjustable unit found on the Jota and along with the beautifullyengineered and equally adjustable rear-set footrest controls, the ridingposition is perfect for fast and relaxed riding.But the bike is loud. In town you have to take real care to keep the noise downif you've any sort of conscience.
Though we weren't able to test thedecibel level it must break the limit quite easily.Fortunately the engine doesn't baulk at poodling around town should you be in asensitive state of mind. The engine is very flexible, 2,000 rpm.It's very smooth too. Like the Alpino, the Montjuic's power unit has 180-degreethrows and is strongly supported in four ball bearings. And to tame anyvibration that might exist, a small counterbalancer geared to the crankshaft inthe primary drive case offsets the rocking couple inherent with this sort ofengine. Result is that the motor spins happily through the gears up to well overthe 8,000 rev counter red line with no more fuss than a slight rattling of youreardrums.
Complementing the performance thehandling and suspension are tight and taut as you might expect of a machine thathas been trimmed down to about 350 lb dry without changing the spring rates. Andfor the same reason the three Brembo disc brakes have no trouble in hauling upthe lightweight bike from speed.
Neither is the machine finicky. JohnOwen Reckons he has been getting 55 mpg in the 2,000 enjoyable miles he's runthe machine.If you can live with such single-minded exotica, the Montjuic is an obviouslyrewarding machine to own.