Lighter Volvo could tip the balance
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WITHOUT a totally new vehicle to show at the NEC last year, Volvo tried to steal some of the limelight with a surprise exhibit — an F7 6x4 with a lightweight rear suspension bogie.
Clearly aimed at such vehicles as the Leyland Reiver/Bison and Ford D-Series — now Cargo — the F7 L ride, as it is known, has a kerb weight of 6,400kg (6 ton 6 cwt) for the shortest wheelbase model, making it one of the lightest available.
This makes it particularly suitable for applications where some off-road running is involved — such as mixer work, tankers and brick delivery.
The new bogie — which alone accounts for much of the weight saving over the T ride six wheeler — is a four-spring setup as against a two-spring.
Conventional slipper-ended leaf springs are connected via a rocking balance beam which is said to make the bogie non-reactive. The bogie, I understand,
was deigned in Sweden and it even looks lightweight.
Gone is the inner chassis liner, and a rear cross-member is no longer needed because suspension forces are channelled into the chassis through different points.
A 200 litre (44 gallon) fuel tank is used instead of the 300 litre (66 gallon) one on the T ride model.
Maintenance-free batteries are used and the front wing extensions are made of tough plastic. Finally, Rockwell wedge brakes are used in place of the S cam ones on the heavier vehicle.
Unlike the T ride model, brake dimensions are uniform all round 381mm (Thin) diameter with 178mm (7in) wide linings.
All in all the changes have resulted in a weight difference of a ton between the two vehicles. Though only one engine is offered — the TD7OG — there are a choice of wheelbases — 3.6, 4, 4.4 and 4.8m (11.8, 13.1, 14.4 and 15.7ft). Volvo offered us the shortest of these for test, but were very anxious we should "understand what the vehicle is designed for", and not take it over terrain which was too rough.
Working on the basis that if a vehicle looks as if it is capable of off-road operation it will be used for that, we decided to carry out our normal tipper test.
In spite of Volvo's obvious nervousness, the L ride acquitted itself very well, coping with everything we threw at it — indeed fuel consumption results were better than those for its heavier brother at 36.88 lit/100km (7.66mpg) against 37.3 lit/km (7.58mpg). But it must be said the L ride had a weight some 240kg (5 cwt) I There was half a mile an in it on overall average sr with the L ride being the sl at 37.5km/h (23.32mph).
Our tipper test, as rei readers will know, consists day's testing at MIRA to rE acceleration, speeds in g braking performance and s( This is followed by a seconc of gruelling on/off road wo record fuel consumption re and assess generally if vehicle concerned is up tc job it was designed to do.
It also shows how comfon the vehicle is for a tipper whose life is spent caret over rough terrain.
The first day at MIRA duced wheel locking at e speed, but there was no dence of reaction from the bogie — all four wheels pea red to be locking to the s. degree.
But one nasty incident occur during the last 64k (40mph) stop. Until then brakes had been behaving v but for some reason they denly decided to pull violentl the right.
The rear off-side wheels the ground and the whole oi seemed in imminent dange "falling on its ear." I don't t) for one minute the pulling ■ caused by any fundamer problem with the F7's brak system, and indeed Volvo cc find no defect with our • vehicle.
Certainly during the rest of test, the brakes gave no pr lems, though it must be said full pressure stops were nec sary. I can only imagine Dle was caused by a heat I up and subsequent imba? between the two front eiS, exacerbated by the load ng shifted during previous S.
all other respects the Volvo Drmed well at MIRA, even 3rting on a one in four grat to the surprise of the pany engineer.
ie park brakes spring 3 operating on the second third axles held easily on Dne in four gradient both up downwards.
tere is only one power unit ;Hied for the F7 L ride the OG. Based on the wellArn 6.7-litre in-line six, it is smallest output engine rirrg 150.5kW (202bhp) net at !Orpm.
Jt if the optional viscous piing fan is fitted (as was the t on our test vehicle) maxiri output is brought down to ,c1A/ (197bhp).
I practice, the fan rarely ms to be engaged, so I pose it's true to say slightly re than 150kW (202bhp) is bedelivered, then, as this figure )r a fixed fan.
ower was definitely not a blem during any aspect of test, as with a power-toght ratio of 6.18kW/tonne .2bhp/ton) the Volvo was ongst the front runners.
ve always liked the R52, ht-speed range-change gear c (I must confess to preferring ge changes anyway) and with its synchromesh it's a joy to use. There's no hesitation in changes and no obligation to double-declutch few people realise just how damaging this is on a synchromesh gearbox.
The short lever comes easily to hand and, apart from a weak detent spring into reverse, the gate is nice and positive. It was possible to skip gears to get the L ride rolling along, and starting off in second was always the order of the day.
Engine and gearbox were so well matched that there was never any suggestion of ratio gaps being wrong. The turbocharged TD7OG (bigger output units also have intercooling) is flexible for such a small capacity and the revs don't seem to "die" easily. Perhaps this accounts for the ease of driving I came to associate with the F7.
If the engine/gearbox match was good, the power steering must rate as excellent. So fine_ was it that although we suffered a front-wheel puncture on the rough road circuit, it didn't show up until the tyre was virtually flat! There was no apparent pulling and the steering effort didn't rise appreciably.
Until the tyre finally went right down on the rim, we thought the hissing was an unloader valve on the braking system which had become stuck.
Volvo staff men protested, but we decided to take the vehicle out over the really muddy sections of the off-road test areas. And it stood up very well.
The engine pulled strongly, even when the gear was toc high, and the F7 was on full lock plugging through thick mud.
There was never any need tc use the diff locks (bogie axle diffs and an inter axle lock) al. though these are provided.
All in all, the L ride seemed 8E capable of taking on just aE much rough stuff as its heaviei brother. Possibly, though, the unflitched chassis and fairl} lightweight would not stand up to repeated doses of this kind 0. work hence the Volvo anxiety.
Volvo has always had drivel appeal, starting with the F86 anc F88 and carrying right througf to the present day. The F7 is cer tainly no exception, and its ver sion of the Club-of-Four cab is 2 well-trimmed and equipped.
Interior noise levels are low we recorded 73dBA at 40mpf and 78dBA at 60mph. The en gine cover is carpeted but rub ber mats are used for the driv er's and mate's foot wells.
With the F7 cab beinc mounted higher on the chassis the engine hump is smaller thar the F86, so cross-cab access reasonable.
A higher cab means moo steps up, but these are well placed; but a grab handle at thi rear of the door opening would have aided entry — at present the driver is somewhat unbalanced. This can't be a good thing on a tipper, where the driver has to get in and out of the cab so often.
The steps are steel, with grilles to allow mud and water to escape.
Behind the wheel, the Bostrom suspension seat is very comfortable, but I found insufficient up and down adjustment to arevent me looking at the top Nindscreen surround rubber.
The park-brake control is lo;ated in front of the gearlever ]nd has a massive detent to )revent its accidental enjagement or disengagement one of the criticisms of the old :86 was its very uncertain park )rake control mounted on the )ngine cover).
On our tipper, the pto enjagernent was fitted behind the learlever on the engine hump — n a very accessible position. It is imilar in appearance to a small lark brake unit, and is as easy to ise.
particularly like the F10/12 ipe steering wheel now fitted to le F7. It has four slim spokes leverly angled to give a clear iew of the instrument panel, nd its centre is flat enough to How a clipboard to be placed cross.
The pedals — the clutch is endant, the others organ — are well-placed with enough si for booted feet and have rul covering.
Still sticking to its own %A/a doing things — they call it e nomics — Volvo has stalks the left of the column for wii and indicators, while the Li! are controlled from the d board.
The rest of the instrumi and controls are laid out i sensible and workmanlike v and at last Volvo has ad revolutions in rpm as well revs per second.
Forward visibility — header rail problem apart good as indeed it is all ro with rear cab windows and sr quarter side windows behind doors.
Talking of the doors, I've nE found them to shut too well any F7. They always need tc slammed shut to catch — e winding down the wind doesn't make it any easier. Volvo does provide a substar grab handle on the door perhaps one shouldn't cc plain.
If the driver should be hat with his working environmen the F7, the same should also true for the maintenance m Tilting the cab to its maximun 52° is easily done by means oi hydraulic pump, and it offers cellent accessibility to mE components.
Daily checks also present I problems, with twin lift
panels at the front — the toi solid metal one, the lower, • grille.
There are two safety hand on the top of the upper fb front panel to allow the driver