Honda CB1100R T-Rex motorcycle test

Menus

• The best Post-Classic sports car ever built
• 4 cylinders in line, 1,156 cm3, 145 hp, 160 kg, Harris frame, 273 km / h
• Genesis
• Discovery
• 1,000 US $ per kilo !
• Test
• Cycle part
• Braking
• Conclusion

The best Post-Classic sports car ever built

4 cylinders in line, 1,156 cm3, 145 hp, 160 kg, Harris frame, 273 km / h

A T-Rex is big, strong, powerful … and this is also the case of the Australian trainer T-Rex Racing Developments, not in reference to the prehistoric monster but to its creator Rex Wolfenden. And it is also to him that we can attribute the success story of the historic Post-Classic races in Australia..

It all started with his K&W Honda dealership in Melbourne, which he ended up selling 25 years ago. Since then he has focused full time on building and racing Period 4 (1963-1972) motorcycles with motorcycles derived from Honda CB750 models and the more recent Period 5 (1973-1982) with twin shaft machines. with cams and 16 valves. Now 69, the former motocross rider and footballer has become an icon many riders have tried to beat..

Test of the T-Rex Honda CB1100R

Genesis

Rex Wolfenden is both a pilot and an engineer. It was he who prepared them before leading them on the track. Rare today, it is a combo of talents that explains its success at the time. It must be said that he was not just any rider: 10 years of motocross career on Maico and Kawasaki at the highest level, then another decade devoted to his K&W dealership, before returning to road racing in 1988. , like a break in his Australian football career:

Football remained my priority until 1991, but by then the lap records were starting to drop and victories on the bike, so I focused on that. It was difficult to run on a bruised and beaten Sunday after the Saturday football. I have broken more bones and had more operations playing Australian football than I have ever suffered in motocross or on the asphalt !

Rex Wolfenden was a footballer, driver and dealer

The original choice of the Honda CB750 for racing was a no-brainer for Rex, especially since there is no power limitation for the pre-73 four cylinders in Oceania as there may be in the Kingdom. -United to protect local twins and triples in classic races.

I wanted to drive a brand that I was selling. Post-Classic racing with a Honda Four was a good, economical choice, thanks to all the bikes available for parts. Also, the rules allow a lot of development as long as you use period pieces or replicas of them. It pleased my engineering team. Also, it allowed me to race with bikes that were great when I was a kid. We all like to take a step back in time and feel younger than we are when we manage to get out of it. !

It must be said that Rex has won the title of Australian Post-Classic Period 4 champion seven times in eleven years. And his biggest competitors were his clones, that is, the CB750s he had built for his friends and customers. Because winning so many titles had encouraged the pilots to equip themselves like him. It was not uncommon to see three Honda built by Rex in the first three places, recreating the spectacle offered by the ancestors of modern Superbikes. This is also a category in which the Wolfenden family is interested because Rex’s brother, Clyde, was for many years the team manager of Honda Australia Superbike. He is the man who led the local riders and who powered riders like Troy Corser, Anthony Gobert, Kirk McCarthy and many others making them Australian Superbike champions for several successive seasons on Honda, before moving on. go in search of fame and fortune abroad with other brands.

Wolfenden at work on a frame in his workshop

The advent of the Period 5 category saw Rex take on the challenge of competing against stars of the past who have come to help create what is arguably one of the most entertaining shows in road racing today..

In Period 4 I dominated overall, but I probably arrived in Period 5 a little late. There were guys like Robbie Phillis and other big name riders who were on these bikes and they were a little harder to beat! I have never been at the level of a Robbie or Malcolm Campbell as a pilot, but I stayed the course and had a great time, this is the most important.

More precisely, reducing his driving time in favor of workshop work meant more chances of developing the arrival of drivers perfectly prepared for the Post-Classic by equipping them under the T-Rex Racing Developments banner from his Melbourne workshop..

When I sold my dealership to focus on the Post-Classic, a few alumni in the area lodged me up telling me that I was wasting my time with these dinosaurs! They called me Tyrannosaurus Rex so I shortened it to T-Rex and it’s eye-catching !

The man then left his dealership activity to devote himself fully to preparation with his T-Rex Racing Developments workshop.

While the performance level increased dramatically in the P5, with 180 hp Suzuki Katana and XR69 TT F1 powered by lightning-fast engines, Wolfenden kept pace with his Honda T-Rex despite the loss of power and displacement in the face of competition by focusing on reliability and handling. This resulted in the creation of the Honda CB1100RR with Harris frame..

This Honda CB1100RR Harris is waiting for me today in the pits for a test drive at the Broadford Bike Bonanza. If that name doesn’t mean anything in Europe, this is the annual Australian Easter Classic Motorcycle Event..

The No.1 plaque she proudly displays is reminiscent of the Post-Classic P5 title streak she won at the hands of Michael Dibb, former GP 500 rider Paul Young and World Superbike wild card Jed Melcher. who won two of four races at the 2016 Island Classic Match and shared the win on a tie with Jeremy McWilliams. The results of the CB on the track in the hands of three different drivers confirm that it is among the best Post-Classic sports cars ever built.

Discovery

In fact, the CB1100R was Honda’s first special homologation: a fully faired single-seater sports motorcycle produced in only 4,050 units between 1981 and 1983. This number is enough for it to be considered a production motorcycle in the markets where it has been produced. been sold, namely Europe, South Africa, Australia and New Zealand, but not in the United States. There, the similar but unfaired CB1100F was available from 1982 to 1984 and also available for the AMA Superbike before the advent of the VF750 Interceptor. In 1981, the CB1100R won the Castrol Six Hours in New Zealand with Australians Malcolm Campbell and Mick Cole. In 1982, these Honda took the first four places in the Australian equivalent, with the future world champion Wayne Gardner, associated with Wayne Clark, in the lead. It is therefore a motorcycle with a serious sporting heritage. Despite this, in 2012, Rex Wolfenden decided to replace the original Honda frame on the CB1100R which he built to race himself in the P5 events but this time with a Harris chassis..

The T-Rex Honda CB1100R

1,000 US $ per kilo !

It’s quite difficult at the front lines. And since I could only push the Honda engine to 1,156cc, I had to catch up with the bigger 1.300cc Suzuki and Yamaha engines. But weight is speed. The Harris frame offered the possibility of drastically reducing this by 17 kg compared to the original CB1100R. It’s a big saving, in weight but not in price, because it costs almost $ 1,000 per kilo! I have cast magnesium Dymag wheels that cost $ 1,600 each and on the big parts I used a lot of titanium, plus the fairing, saddle, tank, everything is super thin and as light as it gets. So while I gave the engine a bit of a boost and got a bit of horsepower, the extra speed and handling on the track all comes from the weight..

The resulting bike is a feast for the eyes with this British-made CrMo steel frame based essentially on a Harris Magnum frame first designed in the late 1970s. Rex additionally admits to having subtly modified it to his arrival in the southern hemisphere.

The bike sits on a Harris modified CrMo steel frame

The frame technology had been very good for over 30 years. But I moved the engine a little forward. The repositioning allowed more weight to be carried on the front wheel. I also raised it at the rear to get a better final transmission of the chain and to adjust the accelerator to the millimeter, which is very important. At the time, they did the same on slightly older motocross bikes by using a cantilever mount for the rear shocks. Road racing suspension is all about damping, it doesn’t matter how much wheel travel is and that makes the springs and shocks very difficult to adjust if you have too much travel and leverage. So I cut the back of a brand new frame and mounted the shocks in a more conventional way. Rear travel is only 100mm, but I have full control over the suspension.

Rear travel is reduced to just 100mm

Fully adjustable Ohlins twin shocks provide this control via the square-section swingarm, matched to the front of a 41mm Showa cartridge fork from a 1990’s Honda CBR600 with a T-Rex interior and mounted in aluminum triple tees machined by C&C Engineering Concern, brother Clyde’s company, who also made the handlebars, footpegs, levers and other beautiful parts on the bike. Dymag cast magnesium wheels are shod for my Pirelli Supercorsa 2 slick tire test and use oversized titanium hubs, which is also the material used for the swingarm pivot pin. C&C also made the replica Suzuki XR69 310mm steel discs clamped by AP-Lockheed twin-piston calipers as well as the 230mm rear disc to match a Brembo twin-piston caliper. The chassis geometry is quite sporty, even by modern standards, with a 24 ° open fork and 100mm trail, although the wheelbase is a bit long at 1,475mm. The claimed dry weight is 160 kg, which is incredibly low for a machine of this type and is distributed 52/48% over the front thanks to Rex’s modifications, which however did not stop there..

The Цhlins shock absorbers find here a traditional fixing

To Harris’ credit, the frame is very light compared to a stock Honda CB1100R frame, as you would expect from a CrMo steel frame. But it broke my heart to put a kilo of metal on the frame because there were a few small flaws in the design of the frame that had to be corrected. It cost me a kilo more! But the fuel tank is nice and light, and the trim is a simple Kevlar sheet.

This wonderful wheelset looks muscular and powerful but also pretty, thanks to the prepared engine that visually dominates while producing 145 horsepower at 9,500 rpm at the rear wheel. This one uses CB1100R crankcases and a heavily modified stock crankshaft, which Rex has lightened by 2.5kg by bevelling it to cut better through the oil in that wet sump engine. The crankshaft receives Carillo connecting rods specially designed for T-Rex by the Californian specialist. It is topped with modern Honda forged pistons used in several current models with the engine bored 3mm to 73 x 69mm and a capacity of 1,156cc. Modified combustion chamber cylinder head follows RSC (Honda’s pre-HRC racing division) improvements to one of Clyde Wolfenden’s historic collection motorcycles.

Bore at 1,156 cm3 the Honda 4-cylinder delivers 145 horsepower

My brother owns one of the last Honda TT Formula 1 series bikes using this engine, so I saw the interior of it and it couldn’t be better than the RSC. I pretty much copied what they did in the factory cylinder head which is to close the intake ports a bit, install much larger intake valves, and use a traditional camshaft. with a lift of 9 mm. Everything works fine, just as Honda had proven by winning the World TT Formula 1 with this engine.

Compared to the stock CB1100RR engine, there are 1.5mm wider intake valves and 1mm thicker exhausts, two per cylinder, each carrying only one S&W valve spring. . The 5-speed gearbox comes from the original CB and is mated to a replica of the factory RSC dry clutch copied directly from the Clyde engine and fitted with Ducati discs. The ignition is done via an Electrex World digital CDI. The 4-2-1 titanium exhaust and silencer were manufactured in Great Britain to T-Rex specifications and then assembled in Australia. Weighing only 2.5 kg, the titanium line is half the weight of the stainless steel one it replaces. The engine carries a quartet of Keihin CR 35mm carburetors and Rex is constantly experimenting with horn length to optimize carburation.

To limit the weight as much as possible, the exhaust is made of titanium

I have tried different combinations. Right now I have all four of the same length, but sometimes I use two different lengths. The lengths of the intake ducts and the combination of the cones aim to obtain a correct carburation and to draw a good linear power..

Test

And that’s what he did, as my essay at Broadford amply proved. The original starter has been removed. So after cranking the engine to the starter bank, I headed to the pre-gille where I discovered that neutral is absolutely impossible to find at the left shift selector reversed (one gear up, four down). The only solution is to keep it moving when heading towards the gate. The engine settles on a fairly high idle at 1,800 rpm, an old trick from the days before slip clutches to avoid dreading the slamming of the engine brake..

But once slender, the Honda delivers crisp, alluring acceleration that borders on explosion and seems at odds with its far wiser nature. This is a fairly unexpected 145 hp coupler motorcycle and I can imagine it being great for riding in the rain or on a slippery track, in conditions where I doubt its 180 hp Suzuki rivals are comfortable. . Rex Wolfenden says he has managed to squeeze 180 hp from this engine at the rear wheel, but only at the cost of very aggressive horsepower and a limited rev range that strongly affects handling..

The T-Rex is very lively from the first acceleration

Instead, with around thirty fewer horses and on which Paul Young was still flashed at 273 km / h at the end of the Phillip Island straight in 2015, it is an extremely manoeuvrable motorcycle up to 95% of its potential. She is happy to forgive and is pleasant until one starts looking for that remaining 5%, when it would take the talent and intelligence of a Young or a Melcher to reach them. Sure, there’s a surplus of power and speed in the high revs towards the red zone at 9,500 rpm, but the Honda T-Rex has such linear power and torque so low that it’s well suited to a winding track like Broadford. It pulls hard, but cleanly from a standing start without needing too much of the clutch. It then easily comes out of a slow turn in seconds from 4,500 rpm.

The 145 hp can reach up to 273 km / h

The maneuverability is there. The arrival of power is linear. The response to acceleration is clear. And the optimized chassis configuration improves on / off behavior under acceleration. All this combines to facilitate the return to force on the accelerator despite this thin rear tire, while continuing to turn when exiting a corner. The large bubble is very protective without affecting the ability to position the bike on a curve. And you don’t feel detached from the action, which can sometimes be the case with such a large screen. The Harris chassis combined with Rex’s upgrades together provide good handling and agility to shift from angle to angle in Esses..

The bike knows how to take advantage of its agility

Cycle part

The Pirelli SC2 rear slick grips effortlessly and makes you forget you’re riding a historic dual-shock artifact as this bike feels so much more modern in terms of handling. When she begins to slide, she does so in a very controllable manner, with the wide handlebars allowing for instant backward slip correction..

Pirelli tires provide excellent grip

Braking

The brakes are not brilliant on the other hand. I am used to my Ducati 750 SS from the same period and yet use the same calipers as the Honda T-Rex, there is a real difference. It must be said that my Desmo V-Twin uses Brembo steel discs instead of Rex’s Suzuki copies. Rex warned me that there were carbon pads in the front calipers. So I duly warmed them up along the straight line, keeping a finger on the lever during my warm-up lap. After that, they were biting fine, but in a rather gradual fashion without that instant bite you get on a cast disc with those same calipers. So you have to establish your braking points and stick to them no matter what, because there is no reserve of braking power on this bike. This means that there is no additional braking in case someone cuts in front of you or if you arrive with too much optimism on a curve..

Braking, on the other hand, leaves no room for error or improvisation.

Conclusion

Braking! This is the only criticism I can make on what is a great piece of empirical, man-made development that is rightly synonymous with Post-Classic racing. Supple, forgiving but quick and above all torquey, this engine is the star of the show, housed in a beautifully tuned motorcycle that almost looks too good for the race. It is amazing how much a modern motorcycle looks like a classic forty year old sports car. Far from having too much power for its chassis, the Honda T-Rex is an agile and surprisingly fast sports car despite its narrow rear rim which has to deal with too much power for such a small contact patch. The Honda’s acceleration is truly impressive, even compared to modern motorcycles, aided by its light weight. Rex Wolfenden did a great job in developing this bike. This is dinosaur !

Honda CB1100R T-Rex ready to hit the track

Strong points

• Motor
• Agility
• Look

Weak points

• Braking

The technical sheet of the T-Rex Honda CB1100R

Related articles

• Honda CRF 250 L motorcycle test

  A little trail that sparkles The great Escape You don’t like small cars? So be sure to read this article! Because after discovering this new Honda, you…

• 2012 Honda Goldwing GL 1800 motorcycle test

  Majestic Asphalt Diva. Icon of road machines, imposing and luxurious, Honda carves out its generous muse with small touches. Thus, 2012 will certainly…

• Yamaha VMax 1700 motorcycle test

  The return of a legend The return of the good, the bad and the tonic-truante. Certain celestial objects cross our orbit according to a periodicity which…

• Honda CB 1100 motorcycle test

  A mechanical celebration of the famous CB 750 Four, the CB 1100 combines neo-retro aesthetics and current performance. Without sacrificing anything on…

• Honda CBF 1000 ABS motorcycle test

  The Honda CBF 1000 is the big sister of the CBF 600, which appeared in 2006. Apart from a slightly larger size, the two models are aesthetically very…

• Ducati 350 SCD motorcycle test

  From the circuit to the road for the Italian sportswoman 4-stroke single cylinder, 340 cc, 42 hp, 210 km / h, 112 kg dry In 1954, the arrival of Fabio…

• Honda CBR 1000 RR SP Fireblade test

  Easy girl The SP version of the Fireblade pushes the concept of Total Control dear to Honda to its climax, namely offering an ultra efficient machine and…

• Honda CBR1000RR-R Fireblade SP motorcycle test

  The meaning of paradox or how to abandon Total Control for Total Taule 4 cylinders in line, 999 cm3, 217hp, 113 Nm, 201 kg all full facts, 24,999 euros…

• Honda VF 500 F2 test

  Little pearl of Asia Introduced in 1984, the Honda 500 VF came at the start of the wave that saw Honda bet everything, or almost everything, on this…

• Exclusive BMW K1600 GS Mammoth motorcycle test

  Special K on two wheels 6 cylinders in line of 1,649 cm3, 160 hp, 175 Nm, 310 kg full made, 39 liter fuel tank, tubular frame, Dynamic ESA suspension……