Yamaha FZ 750

Oct 1987

Yamaha themselves have taken steps to improve the basic FZ's handling. In a couple of issues' time we should be in a position to comment more definitively on this, if and when a megatest we've got planned comes off. In the meantime, the chassis changes on the '87 model include lighter brakes, and a different rocker arm setup on the rear suspension which alters the rate of progression under full bump and gives 10mm extra wheel travel. This last.modification will benefit racers, many of whom have complained in the past about the incorrect length of the suspension's bottom link. One assumes that the new linkage is now more closely modelled on the works racers' units. Other changes have been to dispense with the linked air adjustment of the forks and the rear shock's damping adjuster knob, following research which showed that a very large majority of contemporary motorcyclists never alter the standard settings. There is still spring preload adjustment front and rear though, only now it is effected at the front by GSX-R style screws atop the fork legs. The centrestand is ditched on the '87 model, and a full fairing included in the spec.

If you can't be bothered going to the trouble of obtaining and/or fitting aftermarket mods, you could always try to buy an FZR750R. This machine forms the basis of what might at first appear to be works open class FZR1000 racers, and has trickled into this country in very limited numbers (approximately 20 — Padgetts had most of them). Effectively, the R is a 750cc version of the FZR1000. For a start, the R inherits the 1000's Deltabox frame, which has the effect of reducing dry weight by 2kg. Then there's the switch from a 16in to a 17in front wheel, with radial tyres fitted on much wider aluminium rims (3.50 front and 4.50 rear instead of 2.75 and 3.00). Brake disc size is up to FZR1000 size, from 267mm to 320mm on the front pair, slowed by four-pot calipers.

The R has thicker forks, up 2mm to 41mm, and less front wheel travel than the stock 750 (down from 5.5in to 5.1 in, again identical to the 1000). The R's petrol tank carries one litre less fuel, and does away with the FZ's electric fuel pump system. We'll talk about the FZR's mechanical mods later, at the same time explaining why this is a bike for race use only, and not really a serious road bike alternative.

Assuming that you have a standard FZ750, chances are you're pretty well satisfied with your bike's handling. The only real glitch we found with our first FZ test bike was a tendency for the standard Bridgestone Exedra tyres to go off very quickly when hustling round a racetrack. But of course it's only to be expected that shortcomings which you would never notice on the road can start to become a problem during racing use.

With this in mind, we rang Steve Harris of Harris Performance. Steve was a mine of information on Suzuki GSX-Rs last month, and he proved equally knowledgeable on the Yamaha FZ. Obviously, many of the tricks that work with the Suzuki are valid for the Yam too. Steve acknowledged that the factory mods which appear on the FZR750R do solve many of the problems, but he recommended the use of a thicker fork brace (Harris do a Viinch dural one).

The twitchiness associated with the Suzuki is not a problem on the Yamaha, so Harris don't bother to alter the head angle on race bikes. A special adjustable yoke is available for about £150 which allows a 31mm offset on the '87 model (32mm for earlier models). Steering dampers are always a good idea, but fitment isn't exactly a doddle on the FZ because of the fairing panel holding the choke/fuel switchgear. Harris are currently making up a batch of Yamaha works replica dampers, which will be available by the time you read this. They'll be priced at the luxury end of the damper market (look at around £60-£65).

Fork springs should be uprated for racing) FZR1000 ones are used on the Russell Benny/Steve Bateman/Richard Burden Phase One Endurance bike. At the back end, Harris can brace up your standard swingarm. Steve reckons this is quite difficult to do on the FZ, but their charge of £85 is the same, as for the same job on a Suzuki GSX-R.

What about the new rocker arm on the '87 bike? "There's a bit of a misconception among some racers about the rate of progression on the new arm," Steve told us. "On the old models, the ratio was 3:1. Now it starts at 3:1, and goes up to 2.5:1 — not 2:1 like some people think." As with the Suzuki, Harris junk the standard rear shock in favour of what used to be a White Power replacement, but what is now almost exclusively an Ohlins unit. Serious rides will benefit from having more rubber on the road.