YAMAHA FJ1100 T-REX
Check out this very different T-rex Yamaha FJ1200 racer from Down Under and listen to it ROAR!
Here’s one bike that was ‘Born to Boogie’, one of the ‘Children of the Revolution’ and Yamaha’s very own‘20th Century Boy.’‘get it On’ with this 160bhp pared-to-the bone Aussie racer: with apologies to Marc Bolan. Words courtesy of our down under dude Jeff Ware.
The FJ1100 on release in 1984 was a groundbreaking machine – one of the first true ‘hypersports’ motorcycles and one that remained popular for over a decade. When it hit the dealerships it was an instant hit despite strong competition from the likes of Kawasaki’s GPZ900R. Where all manufacturers offered naked bikes, full sportsbikes or touring bikes, Yamaha managed to build a bike that had all of the benefits of the above in one awesome package.
The FJ was seriously powerful at 125hp, capable of over 140mph, with a 10 second quarter-mile time, grunty and reliable with a simple air-cooled 16-valve inline four.
With a wide seat, tall screen, high bars and rubbercapped foot-pegs the FJ was extremely comfortable. It had massive potential for luggage thanks to a generous pillion area and space for rack fitment. Suspension was more on the soft than sporty side, which suited most potential owners who were going to go fast touring… the FJ1100 had a really narrow motor for the day, much like the FZ750 from 1985, as Yamaha had relocated the alternator to behind the cylinders rather than having it off the left side of the crankshaft and all a year before the GSX-R750F came out with the same set-up…
In 1986 the 1100 copped a bore increase and became the FJ1200, making a credible 130hp, still running on the smooth delivery of the 36mm Mikuni CV carburettors. Compression was raised slightly and a few years later the engine got a digital ignition as well. The 3XW ran until 1996 in the UK and there was an ABS version as well. As the bike entered the 1990s it also got upgraded brakes, suspension and styling, but the fundamentals remained and the FJ1200, although dated by 1996, was still a fabulous bike and has left a gap that hasn’t really been filled.
The engine is bulletproof and now has a reputation as THE donk to use for serious classic racing. Here in OZ when we have the Phillip Island Classic or the Barry
Sheene Festival it is a FJ v GSX engine battle up front with the odd Honda CB1100 motor tagging along… so, most FJ1200 motors are punted around at insane speeds in trick chassis generally by Harris, ridden by the likes of Jeremy Mcwilliams, Connor Cummins, Colin Edwards and the list goes on… they get 160-plus hp out of the beasts and fit them out with top spec suspension and brakes, resulting in mind blowing lap times in the hands of these nutters…
“YAMAHA FJ MOTORS CAN PUMP OUT AS MUCH AS 160BHP – JUST LIKE THIS T-REX. SORTED SUSPENSION AND GEOMETRY MAKES THEM CAPABLE OF MIND-BLOWING LAP TIMES!”
Roar of the T-rex!
T-rex Racing is legendary over here, having been racing and building racing motorcycles for over three decades.
T-rex bikes have won countless championships and specialise in Period 4 classic racing, steered by the genius engineering and fabrication skill of Rex Wolfenden, himself a walking legend of our sport particularly famous for his Honda fours and for being captain of the Australian Team each year in the International Challenge, which we won from the USA recently with riders Steve Martin, Shawn Giles and Glen Richards headlining. There is a really good short film about Rex on Youtube, I suggest you find it and watch it. It’s great… (https://youtu.be/rzjmdf8pokm)
Rex loves a challenge and when he purchased this 1988 FJ1200 for a donor motor, he suddenly had a thought about perhaps keeping it an FJ rather than fitting the motor to a Harris or Bimota chassis. This would stir up the gossip in the pits and bring some good publicity as well as turn heads. As far as he knows, this is the only FJ1100 or FJ1200 road race bike racing at national and international level!
The bike cost less than a thousand quid, was rough as guts, but had potential. It was quickly dragged into T-rex Racing’s amazing workshop in Melbourne to be stripped and measured. Rex had a plan to make the bike look as recognisable as an FJ as possible and if you ask me, he has done a stunning job, as it looks absolutely horn!
The engine had to be built regardless, so that happened first. Rex has a successful and proven set-up for these powerplants and went about building a mild one for testing purposes, which would be uprated later on to full noise for Troy Corser to race in the 2018 Island Classic, which he did and finished third, raving about the bike and in fact not even touching one setting all weekend…
The standard 63.8mm stroke remains, however, the
bore is 1mm over at 78mm. Compression ratio is bumped up from 9:1 to 11:1 and JE forged pistons are used. The crankcases are modified and polished, the crankshaft is lightened and balanced and Carrillo con-rods are fitted. The camshafts, spinning in a ported and flowed cylinder-head, are T-rex Racing items and oversized valves are used.
Gearbox-wise, it is pretty stock also with the standard five-speed ratios undercut, a slipper clutch fitted and no quickshifter used (or allowed). Fuelling is taken care of via Mikuni 38mm flatslide carburettors, while a Dyna 2000 ignition sets fire to the pump gas. It’s all then blown out through a stunning Akrapovic race system with T-rex muffler, all in stainless…
Pumping out over 160hp at the engine, the powerplant was set aside and left to look pretty on the bench while Rex concentrated on that heavy and flimsy FJ rolling chassis. The frame was stripped, bead blasted and
then once measured up, it was braced and gusseted where required. The headstock was massaged for better numbers, then the frame was painted black. Looks mint…
Up front the original triple-trees (you Poms call them yokes) are retained, holding re-valved and re-sprung forks. The back end has a heavily braced FJ1200 swingarm, with a custom Ohlins shock and linkages. Both ends wear 17in wheels, 3.50 x 17 and 5.50 x 17 to accommodate modern rubber. Final drive is 520-pitch chain and the brakes are all upgraded. Both ends wear Brembo calipers, braided brake lines, Nissin master-cylinders and the front rotors are NG floating stainless-steel ones. SBS race pads are used. Handlebars are locally made by Tingate, with the rest of the running gear made by C&C Engineering and T-rex Racing…
The bodywork is cool. Obviously there were no FJ race fairings available so this was all fabricated from glass fibre with carbon-fibre sidecovers where the airbox would normally be. I think it looks tough, particularly the snout where the oil cooler is mounted. The glass fibre tank cover is perfect and would fool anyone at first glance.
Riding the T-rex
I was so lucky to ride this bike at the best racetrack in the world, Phillip Island. The weather was perfect and the track was not at all crowded. I managed to sample a few good bikes that day but it was a challenge, one was right-side shift one-up four-down, one was street shift and the FJ left-side race pattern, all back to back! The FJ was the highlight of the day and one of the nicest motorcycles I have ridden around Phillip Island. In fact, one of the most enjoyable production-based race bikes I’ve ridden full stop… I’ve ridden stock FJ1100 and 1200s a lot on the road, mainly back when I was a motorcycle mechanic, so I was expecting, as you would, a fair bit of wallowing, wobbling, running wide and wrestling from left to right.
Rex and crew fired the mighty FJ up with the roller and I was met with a raspy, menacing howl from the mint exhaust system as the FJ warmed up at a high idle, the way an angry racebike does… I hopped on and familiarised myself with the bike. Not much to learn really, handlebars, clutch, brakes, throttle. Simple, old school, no add-ons or electrickery...
I clicked up for first and started to make my way down the pit lane, noticing how many heads were turning. Obviously the FJ attracted some interest over the previous racing weekend, even though it was only here for a shakedown so to speak… as I headed out onto the circuit proper at Doohan corner, I was already impressed by the smooth power deliver, almost CV carb-like, and just how ‘nice’ the FJ felt to sit on, or rather, in. It feels really comfortable in a racer way and like any racing bike with good ergonomics, the FJ feels familiar to me despite having never ridden it. I’d be able to tell it was a T-rex bike even if someone tried to fool me otherwise. It has that sweet T-rex Racing feel about it.
After a lap to get the body loose and the bike warmed up, I started to get more serious. The FJ was urging me on with confidence.
Entering Gardner Straight in fourth gear, I had the throttle pinned, revving the engine to a tad over 9000rpm before shifting to top gear, being fifth. The top-end is strong but not arm-stretching like other T-rex bikes I’ve ridden, however, drive off the turns and useable power is exceptional, it just didn’t have the top-end hit expected (I’m later told by Rex the engine is soon to be made full spec like the others I rode). Gearshift is silky smooth, amazing, up or down the gearbox.
The bike runs into turns really nicely and throttle opening is spot on, Rex really has put the hard work in on his Dyno tuning this bad boy… 5500 to 8000rpm was where this monster really impressed me, so driveable off turns and easy to ride, I was amazed as normally on these brutish machines I’m tired and hanging on for the ride rather than riding the bike, but the FJ was simply a pleasure to ride.
There is no other way to really put it, it’s just so nice and would be neat in the rain. Seating position is purposeful and locked me in nicely at 185cm tall, and the layout of the
“THE FJ IS URGING ME ON. I'M IN FOURTH GEAR AND HAVE THE THROTTLE PINNED WITH THE MOTOR HITTING 9000RPM BEFORE I SHIFT INTO TOP!”
bars and rearsets mean there really is no FJ familiarity in the riding position, it’s purely looks as far as FJ goes…
Another lap into my 20 minute session, I knew how good this bike really was and as I have ridden most of the top running Katanas at the same place, plus previously ridden Rex’s Harris Honda at Broadford Raceway and Bimota YB5 (powered by an FJ1200), I knew this was potentially a top-class winning bike, at least chassis-wise. With one of the T-rex full power engines in, it’d be up the front in the right hands…
The brakes are impressive, without being incredible. They lack the outright power and feel of AP calipers with cast iron rotors but they are still very good for a Brembo/ng pairing and SBS race pads, particularly given the conventional Nissin master-cylinder. I certainly had no issue pulling the bike up into Honda corner and MG hairpin, it just took a big squeeze and some faith – initial bite was savage but a strong squeeze was required afterwards. The rear brake has good feel and the FJ set-up responds well to rear brake input…
Suspension is fantastic at both ends, as to be expected from a T-rex bike, at the level I was riding I could not fault the set-up at any section of the bumpy Phillip Island tarmac. The wheels stayed inline at all times also. Change of direction was what surprised me. I imagined the FJ would be a real handful to muscle through The Hayshed and it really wasn’t. Out of Siberia and up the hill through the ultra-fast turns the FJ was responsive and lively. In fact, it’s really good fun through there…
Overall, the T-rex Racing FJ1200 is a mean machine with a nice side, much like the original road bike was to street riders… It stands out from the crowd and proves that you can make a racer out of a sports touring motorcycle… what a ride!