Honda VFR750F

The Honda VFR750F is a motorcycle produced by Honda from 1986 to 1997, and a six-time Cycle World Sportbike of the Year.[1] Originally intended as a sport bike to compete with the Suzuki GSX-R750 and Yamaha FZ750 it was redesignated as a sport tourer with the introduction for homologation purposes of the Honda VFR750R for the World Superbike Championship, followed by the introduction of the more rounded 1990 VFR750FL. It was fully faired and Honda claimed 104 hp (78 kW)[2] from the liquid-cooled double overhead cam (DOHC) V4 four-stroke engine. All generations of VFR750F since 1990 had an Elf-designed pro-arm single-sided rear swingarm, and since 1986 had durable, gear-driven cams.[3]

Honda VFR750F

VFR750P police variant
Manufacturer	Honda
Also called	Interceptor
Production	1986–1997
Predecessor	Honda VF750F
Successor	VFR800
Engine	750 cc (46 cu in) liquid-cooled DOHC V4 four-stroke, carburetted
Brakes	Front: double disc Rear: disc

The original VFR750F was first introduced to journalists after the 1985 Bol d'Or, and launched at Jerez, Spain. Introduced for 1986 as a complete redesign of the VF700/750F models in order to address some of the camshaft and bearing problems that had become associated with the first-generation Honda V4 engines, and to improve Honda's negative image concerning this engine. Compared to the VF750F, the new VFR750F had greater power output (104 hp up from 83 hp), lighter weight (claimed down 20 kg),[4] a lower center of gravity, a wider front tire, a slightly shorter wheelbase (15mm), gear driven cams, and six rather than five gears.

U.S. tax surcharge laws put in place In 1987 that penalised large-displacement imported motorcycles in order to protect the troubled Harley Davidson Motor Company resulted in 700 cc VFR700F "tariff buster"[5][6] versions of the first-generation bike, replacing the original 750 cc model.

A number of variants of the bike followed.

Engine

The VFR750F models all used 748 cc 16-valve gear driven DOHC liquid-cooled 90° V4 engines with carburettor-based air/fuel induction; the bore × stroke remained the same for all 750 models at 70.0 mm × 48.6 mm (2.76 in × 1.91 in). The engine was made of cast aluminium alloy with the crankcase being divided horizontally, VFR750P and VFR750K models use slightly different crankcases with the lower casing being modified to allow for the gear position indicator in place of the neutral switch. On all the VFR750 models the gear drive for the cams was between the cylinders. Lubrication was via a wet sump with a chain-driven, dual-rotor oil pump; an oil (air) cooler was also fitted. The transmission was a 6-speed, with a constant-mesh, wet multi-plate clutch and chain drive to the rear wheel with the exception of the 5-speed VFR750P which had a spacer in place of one of the gears.

The VFR750F uses a 180° crankshaft, instead of the 360° crankshaft used in the VF and VFR750R.

In comparison to the VF750 almost every component had weight shaved off it, each connecting rod lost 90 g (3.2 oz), rocker arms 6 g (0.21 oz), intake valve 0.5 g (0.018 oz), exhaust valves 1.5 g (0.053 oz), pistons 20 g (0.71 oz), piston rings 1.3 g (0.046 oz) per set, valve springs 17 g (0.60 oz) each.[4]

The V4 engine has proven itself highly reliable, with few known faults. The gear-driven camshaft system removed any lingering concerns about cam-chain maintenance, which had dogged the VF-series of Honda V4 engines. Valve adjustment on first-generation VFR750Fs was by screw and locknut, which changed in 1990 to shim-under-bucket, along with the valve-clearance inspection interval to 16,000 mi (26,000 km). However, RC36 engines have been known to reach well over 50,000 mi (80,000 km) without any need to adjust the valve clearances.

Chassis

The 1986 VFR750F used what Honda call a diamond type frame, this is because the engine is "set" in the frame like a precious stone is set in jewellery. This design of frame is now referred to as a twin spar. The 1986 VFR750F frame uses the engine as a stressed member and has a cast aluminium headstock joined via 28 by 60 mm (1.1 by 2.4 in) extrusions to the rear castings. The downtubes are 30 by 40 mm (1.2 by 1.6 in). The VFR750F was the first of the 750 class to have an aluminium twin spar frame, weighing just 14 kg (31 lb) and the nearest thing on the road to the VFR, the GSX-R also had an aluminium frame but it was of a conventional twin cradle design.

Suspension

First-generation VFR750Fs sported anti-dive (adjustable on some models) on the damping-rod front 37 mm (1.5 in) Showa forks (uprated to 41 mm (1.6 in) for 1988) and a conventional, dual-sided aluminium swingarm with a centrally located Showa damping unit with remote hydraulic pre-load adjustment at the rear and a pro-link suspension linkage.

Second-generation models had non-adjustable 41 mm (1.6 in) cartridge-style Showa front forks, coupled with a remotely adjustable (for pre-load) emulsion-type Showa shock absorber and the trademark single-sided swing arm. Honda soon upgraded the VFR750F's suspension to include pre-load adjustment on the forks, and damping adjustment on the shock. The bike's distinctive swing arm, derived from the Elf-designed race-bike Pro-Arm development work, has the advantage of allowing rear-wheel removal without the need to remove the drive chain or rear axle, and allows chain adjustment to be made very simply with no concerns of altering wheel alignment.

Third-generation VFR750Fs continued to use the same basic suspension components as the VFR750FN/P, though the single-sided swing arm was redesigned to reduce weight.

Models

The VFR750F can be divided into three distinct generations, with significant revisions having taken place upon the introduction of the VFR750FL in 1990 and the VFR750FR in 1994. The VFR750F ceased production in 1997 with the introduction of the VFR800Fi, marketed in the US as the "Interceptor" and in the UK as the "VFR".

1986–1987 — VFR750FG/H (RC24)

• 
  Honda VFR750F RC24
• 
  Honda VFR750F RC24

New model based on a complete redesign of the VF750F, full fairing, alloy twin-spar frame, gear-driven camshafts, and 16 inch front and 18 inch rear wheels. The VFR750FG also had a cam sensor which was omitted from all later versions. US and Canada models had round gauges while all other models had square gauges.

1986–1987 — VFR700F / VFR700F2 (RC26)

The "Tariff Buster"[5][6] 700cc VFR700F was almost identical to the 750cc version with minor changes to graphics (no 750 on the lower fairing), shorter stroke, different cams and ignition timing. The VFR700F2 was mechanically the same as the standard F but had an upgraded rear shock and fork internals alongside square gauges.

1986–1987 — VFR750RK (RC24)

Not to be confused with the VFR750R (RC30) the VFR750RK was the HRC race kitted version of the VFR750F. Designed for TT F1 and Endurance racing as well as AMA Superbike. The kit bumped the claimed power output from 105PS@10500 rpm to 125PS@12000 rpm[7] due to engine changes including new titanium rods (steel for AMA), pistons (raising compression to 11:1) and cams with larger (optional titanium for the inlet) valves. A new ECU bumped the ignition advance by 5°. Depending on year either the original carbs were modified or a new set were offered as an option.

As well as the engine parts the kit options included a new radiator and optional secondary radiator, modified bodywork, wider wheels, new suspension (forks, shock and linkage) and the option for bars (replacing the clip-ons).

1988–1989 — VFR750FJ/K (RC24)

Minor revision with fairing redesign from a two piece to three piece along with 2-position flip up screen, exhaust redesign, stronger fork legs (up to 41mm from 37mm) but retaining anti-dive on the left leg, a more reliable ignition system and 17 inch wheels front and rear. Larger engine valves for improved midrange along with larger carbs. Gear ratios remain the same but the gearbox shift mechanism was upgraded to the same as the VFR750R (RC30).

A clock and fuel gauge were added and the pillion footrest mounts were changed from being part of the rear subframe to bolt on cast aluminium assemblies. New larger frame castings reduced the amount of frame welding. New fairing side-panels allowed easier access to the engine, and the fairing cutaways for the rider's feet were much reduced in area. The change in wheel size allowed both a greater range of tyre options and a claimed improvement in handling. This model was not imported into the US.

1990–1993 — VFR750FL/M/N/P (RC36)

VFR 750 F RC36

Model year 1990 saw a major redesign in the RC36 version. The forks now featured cartridge dampers, wheels were widened to 5.5 inch for wider tires, and the frame newly constructed. A single sided swingarm allowed for a narrow tail that could accommodate saddle bags while still offering comfort for a passenger. Alas, it also increased the weight by 17 kg.[8]

1994–1997 — VFR750FR/S/T/V (RC36-2)

While keeping the RC36 model number and basic technical layout Honda changed around 200 parts in 1994. Among them were different brakes and riding position, a rear shock absorber with adjustable rebound damping and the tank capacity increased from 5 to 5.5 gal (19 to 21 l).[9] The new model weighed 6 kg less. It was the last of the VFR750F models before the introduction of the VFR800Fi with 781 cc and fuel injection in 1998.[8]Front fairing and lamp were designed similar to the NR 750, as Honda pointed out in advertising.[10]

Japanese market only versions

In the Japanese domestic market other VFR750F variants included:

• VFR750P - A police-specification model with its own distinctive model number (RC35) was restricted to 77 ps (75 hp) due to the Japanese power restrictions in place at the time and fitted with a five-speed gearbox, modified main stand, gear indicator, uprated alternator, crash bars, higher handlebars, and modified speedometer. This bike was not offered for sale to the general public.
• VFR750K - Not to be confused with the VFR750FK, this was a naked style training version of the VFR750F and there were two versions. The first was based on the VFR750FG and retained the RC24 model number. The second was given its own distinctive model number (RC37) with the engine from the restricted to 77 ps (75 hp) VFR750P (RC35). The oil cooler was removed and it was fitted with different foot rests & handlebars, crash bars, a modified main stand and gear indicator. This bike was offered for sale to the general public.

Specifications

Model year	1986-87				1988-89		1990-93				1994-97
Models	VFR750F-G ('86)	VFR700F-G ('86) US Only VFR700F2-G ('86) US Only	VFR750F-H ('87)	VFR700F-H ('87) US Only VFR700F-H ('87) US Only	VFR750F-J ('89)	VFR750F-K ('89)	VFR750F-L ('90)	VFR750F-M ('91)	VFR750F-N ('92)	VFR750F-P ('93)	VFR750F-R ('94)	VFR750F-S ('95)	VFR750F-T ('96)	VFR750F-V ('94)
Model Number	RC24	RC26	RC24	RC26	RC24		RC36
PCN	ML7	MK8	ML7	MK8	ML7		MT4			MY7	MZ7
Engine
Engine Type	liquid-cooled 4-stroke gear driven cam 16-valve DOHC 90° V4
Engine Capacity	748 cc (45.6 cu in)	698 cc (42.6 cu in)	748 cc (45.6 cu in)	698 cc (42.6 cu in)	748 cc (45.6 cu in)
Bore x stroke	70.0 mm × 48.6 mm (2.76 in × 1.91 in)	70.0 mm × 45.4 mm (2.76 in × 1.79 in)	70.0 mm × 48.6 mm (2.76 in × 1.91 in)	70.0 mm × 45.4 mm (2.76 in × 1.79 in)	70.0 mm × 48.6 mm (2.76 in × 1.91 in)
Crank angle	180°
Compression Ratio	10.5:1				11:1
Red Line	11500 rpm
Power (claimed)	104 hp (78 kW) @ 11,500 rpm[2][11]		104 hp (78 kW) @ 11,500 rpm[2][11]								100 hp (75 kW) @ 10,000 rpm[12]
Power (tested)	82.5 hp (61.5 kW) @ 10,500 rpm (rear wheel)[11]
Torque (claimed)							53.5 lb⋅ft (72.5 N⋅m) @ 8,000 rpm[12]				53.9 lb⋅ft (73.1 N⋅m)[12]
Torque (Tested)
Fuel system	34.5mm Keihin CV				36mm Keihin CV
Ignition system	Transistorised with cam sensor		Transistorised
Engine Weight (Dry)	77.3 kg (170 lb)		77.3 kg (170 lb)		77.3 kg (170 lb)
Chassis
Frame Type	Aluminium twin beam using engine as stressed member						Twin Spar
Frame Weight	14 kg (31 lb)
Front suspension	37 mm (1.5 in) air assisted telescopic fork with TRAC anti-dive				41 mm (1.6 in) air assisted telescopic fork with TRAC anti-dive		41 mm (1.6 in) Showa Cartridge telescopic fork				41 mm (1.6 in) Showa Cartridge telescopic fork
Travel	140 mm (5.5 in)
Rake	27°40'						26°
Trail	108 mm (4.3 in)						100 mm (3.9 in)
Rear suspension	Pro-link with remote hydraulic pre-load adjuster				Pro-link with remote hydraulic pre-load adjuster		Pro-Arm with Pro-link				Pro-arm with Pro-link
Travel	105 mm (4.1 in)				105 mm (4.1 in)		130 mm (5.1 in)				130 mm (5.1 in)
Front brakes	Twin 276mm discs with 2-piston sliding calipers				Twin 296mm discs with 2-piston sliding calipers		Twin 296mm discs with 2-piston sliding calipers				Twin 296mm discs with 2-piston sliding calipers
Rear brake	Single 256mm disc with 2-piston sliding caliper
Front tyre	110/90 V16-250 or 110/90 V16				110/80 V17-250		120/70 VR17-V250 or 120/70 ZR17				120/70 ZR17
Rear tyre	130/80 V18-250 or 130/80 VB18				140/80 V17-250		170/60 VR17-V250 or 170/70 ZR17				170/60 ZR17
Dimensions
Length	2,175 mm (85.6 in) Finland / Switzerland models 2,205 mm (86.8 in) Australia models 2,120 mm (83 in)						2,180 mm (86 in)				UK 2,100 mm (83 in) US 2,125 mm (83.7 in)
Width	730 mm (29 in)						700 mm (28 in)				720 mm (28 in)
Height	1,170 mm (46 in)				1,185 mm (46.7 in)
Wheelbase	1,480 mm (58 in)						1,470 mm (58 in)
Ground Clearance	135 mm (5.3 in)						130 mm (5.1 in)
Seat Height	800 mm (31 in)
Dry Weight	198.1 kg (437 lb) (claimed)[2]
Curb Weight (with oil and full tank)
Fuel Capacity	20 L (4.4 imp gal; 5.3 US gal)						19 L (4.2 imp gal; 5.0 US gal)				21 L (4.6 imp gal; 5.5 US gal)
Oil Capacity	With filter 3.1 L (0.68 imp gal; 0.82 US gal) Oil change only 3.1 L (0.68 imp gal; 0.82 US gal)
Engine Coolant Capacity	2.63 L (0.58 imp gal; 0.69 US gal)
Drive-train
Primary reduction	64/33 (1.9393)
1st gear	37/13 (2.8461)
2nd gear	33/16 (2.0625)
3rd gear	31/19 (1.6315)
4th gear	28/21 (1.3333)
5th gear	30/26 (1/1538)
6th gear	29/28 (1.0357)
Final reduction	45/16 (2.8125)
Final Drive	#530 chain
Performance
Measured top speed	151 mph (243 km/h)[3]										152 mph (245 km/h)[12]
Standing 1/4 mile	10.95sec @ 113.95 mph[3]										11.6sec[12]
0-60 mph	2.4sec[3]
45-70 mph	4th 3.76sec[3] 5th 4.64sec[3] 6th 5.20sec[3]
Braking 60-0 mph	118 ft (36 m)[3]
Range	189 mi (304 km)[3]
mpg	45 mpg‑imp (6.3 L/100 km; 37 mpg‑US)[3]

Related models include the VFR400R (NC30), RVF400R (NC35), VF1000F/VF1000R (SC15/16/19/20), VFR750R (RC30), RVF750R (RC45), NR750 (RC40) and VFR800Fi (RC46).

Race history

Although not designed as a race bike, in 1986 British racer Ron Haslam took a standard VFR750F to third place in a soaked Transatlantic Challenge race at Donington Park, UK.[13]

A special VFR750F called the '6X', a 135 hp@13000RPM 188 mph full HRC prototype using RVF cycle parts and containing titanium valves, magnesium cases and flat-slide carburettors, weighing 165 kg (364 lb) (dry),[4] less than the factory RVF that was first ridden by Wayne Gardner at a Suzuka test against TT F1 machinery. Wayne broke his four-stroke lap record by 1.5 seconds.[4] Six examples of the '6X' were built, 4 for the Domestic Championships and two for the American Championships.

The VFR '6X' was raced at the Isle of Man TT by Geoff Johnson, coming in 2nd to Joey Dunlop in both the F1 and Senior TT.[14]

In the US Fred Merkel and Wayne Rainey contested the 1986 AMA Camel Pro Championship, which at the time had both Superbike and F1 races but only one championship, with the best finish of the day counting. Merkel just rode in the Superbike while Rainey did the F1 as well. Merkel won two races and Rainey seven, but the championship was won by Merkel by two points.

For 1987 Merkel's bike was passed to Bubba Shobert who took 3rd place in 1987, being beaten by Wayne Rainey and Kevin Schwantz. The points he earned during the 1987 season gained him victory in the AMA Grand National. In 1988 Shobert won three of the seven races to win the AMA superbike championship.[15][16]

The engine developed in the 6X became the basis for the factory racer, the VFR750R. A race kit was available for the 1986-87 VFR from HRC for US$4,000, this including a titanium exhaust and was known as the VFR750RK.[7]

References

1. Rapid Transit: The 1986 Honda VFR750F Interceptor, motorcycleclassics.com
2. "Honda Sales Brochure". Honda. 1986. Retrieved Feb 7, 2019.
3. Cycle June 1986
4. Honda's V-Force : the four-stroke V4s on road and track. Haynes Pub. ISBN 978-1859604212.
5. Backus, Richard (July–August 2006). "The Honda VF700S Sabre Touring Bike". Motorcycle Classics. Retrieved 2019-09-20. [...] the Honda VF700S Sabre was a touring bike that followed the V45 Sabre. It represents an interesting chapter in motorcycle history as one of a group of Japanese motorcycles referred to as the Tariff Busters.
6. Lemmy (2018-03-05). "Motorcycle tariffs and Harley-Davidson: Lessons from the last time". Common Tread. Revzilla. Retrieved 2019-09-20. Furthermore, many Japanese bikes were reworked to squeak in just under the 700 cc limit; such bikes are still referred to informally as 'tariff busters.'
7. "VFR750RK Setup Manual". Retrieved 7 February 2019.
8. bennets.co.uk: Honda VFR: A history lesson, April 4, 2014, retrieved August 7, 2019
9. https://bikeswiki.com/Honda_VFR750F#Specifications
10. vfr-oc.de - Honda ad from 1991 (german), retrieved August 7, 2019
11. Smith, Robert (July–August 2015). "Rapid Transit: The 1986 Honda VFR750F Interceptor". Motorcycle Classics. Retrieved August 18, 2017.
12. "HONDA VFR750 (1995-1998) Review". Motorcycle News. November 24, 2006. Retrieved August 18, 2017.
13. "1986 Transatlantic Challenge". Youtube. Retrieved 8 January 2016.
14. "Race Results - The official Isle of Man TT website". Iomtt.com. 2018. Retrieved 2011-12-27.
15. "VSB ~ 1986 Honda VFR750". Vintagesuperbike.com. Retrieved 2011-12-27.
16. "Brian O'Shea: AMA Superbike Collector - Mr. Superbike Part II - Motorcyclist Magazine". Motorcyclist. Retrieved 2011-12-27.

External links

• 1986 Honda VFR750 — Bubba Shobert's Factory Superbike, Motorcycle Hall of Fame