Yamaha France flew just a handful of
journalists to Laayoune, in Southern Morocco to test the 2-Trac on
part of the course of the Shamrock Rally, where they already had two
works 2-Trac machines competing in the week-long event.
Four of us had two days sharing two 2-trac machines and two conventionally driven WR450s, swapping between them at will. All four machines had the full complement of Ohlins equipment, so we were able to make a fair assessment of the pros and cons of two wheel drive in a whole variety of conditions, from huge soft dunes to salt lakes and ‘flat-out’ but stony desert with plenty of treacherous rocks hidden by the scrub and sand. We covered a full lap of the rally course on each of the two days, some 400kms in all, with extra excursions into the dunes for photographs and 1WD vs 2WD comparisons.
The first day’s terrain was a mixture of dunes and rocky going, but also included a 40km thrash down the beach, while the second day started and finished with 50kms of tarmac road and included some higher dunes, a rocky plateau and camel-inhabited scrubland.
In view of all the fast going, the test bikes were fitted with tall 15/47 front and rear sprockets instead of the standard 14/50 gearing.
In simple terms the two wheel drive
system can be explained as follows: The gearbox output
sprocket drives a short, fully enclosed chain to a pump, which in
turn pushes the oil (not hydraulic fluid) to the front hub via the
pipe and back via the parallel pipe. There's no drive at all until
the rear wheel starts to spin and only a maximum of 15% of the power
goes to the front at any time.
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