From Graham Dyson, the man responsible for fixing the RG500’s achilles heel--its transmission:

“Letter From: Graham Dyson 

Nova Racing Transmissions

RE: RG500 Dry Clutch & c.r. Gearbox

My involvement with this engine started in 1985 when I was

approached by Clive Padgett of Padgetts of Batley to produce a

close ratio gear set and dry clutch for the then new Suzuki

Gamma, to race in the British Formula 1 class.  This class

allowed up to 500cc two strokes and up to 750cc four strokes to

compete against one another.  The only other rule being that they

both had to be based on road engines.  Up until the RG Gamma

appeared, the only suitable two stroke was the Yamaha LC500. 

Despite lots of effort the four strokes always won.

With only a few months to design, build and test the

transmission, and after two gearbox failures, the new bike proved

unbeatable and reliable.  The championship was won by Mark

Phillips in 1985 and by Darren Dixon, now  world sidecar

champion, in 1988.  (Both on RG500 Gammas)

This was too much for the organisers, who then abandoned the

formula in favour of an all four stroke class.

At the time these events took place I was working with my

brothers, Ian and Tony, who were manufacturers of fairings and

later commercial glass fibre products.  After a disagreement in

1989 I separated from them and started my own company, Nova

Racing Transmissions Limited, at 8 Horseshoe Yard, Crowland,

Lincolnshire PE6 0BJ, U.K.

The specification for the transmission ordered by Clive Padgett

was for gear ratios as close as possible to the RGB Mk 10 factory

racer.  The clutch was to use all available RGB parts which could

be used, without any modifications.  Where necessary, new parts

were designed and manufactured.  Eventually we made all the gears

in the engine from the crank gears to the sprocket.

The success achieved by Padgetts naturally attracted imitators

and a small batch of clutches and gearboxes were made.

Unfortunately, the price of the RGB parts required for the dry

clutch was more than most people were prepared to pay.  At this

point I assumed the project to be at an end.

Much to my surprise I have had a steady stream of people wanting

to buy replicas, not for racing but  for use on the road!!

Being a manufacturer of racing transmissions, I had never

considered the limitations of my gearbox design on the need for

a kick starter.  As far as I was concerned these parts and the

oil pump were consigned to the bin.

The kick starter system used in this engine is of a design long

since discarded by Japanese manufacturers as you can only start

in neutral and must change from right leg starting to left leg

gear engagement.  The normal arrangement via the rear of the

large primary gear allowing for starting in gear with the clutch


My own personal view of the above is that this was part of the

design brief.  At the time the Gamma was produced, Suzuki were

selling a genuine production racer, the RGB Mk 10 at around

£18,000.  The last thing that they wanted was for someone to be

able to purchase a Gamma, fit some parts from the racer and

produce a cut price racer.  The perception at the time was that

this was a cheap way to get an RG.  Many people were

disappointed.   Only Padgetts, who invested considerable sums in

having special parts made were ever really successful...

.....The following is a comparison in percentage terms of the gear

ratios relevant to the Suzuki RG Gamma.

Standard      Nova/RGBType   GHN       Std & Nova 1st Gear


     33.6%          28.2%          23.46%         25%


     21.14%         18.75%         18.34%         21.14%


     15%            11.36%         14.83%         15% 


     10.9%            7.8%          12.6%         10.9%


      8.5%            5.87%        9.63%           8.5%    


1st-6th 63.73%      55.14%         57.75%         58.9%


The standard road gearbox has, apart from 1st gear, acceptable


The RGB type is excellent for racing and would allow very fast

road riding on twisty roads.  On motorway type roads it would

mean pulling peak revs in top gear unless you are prepared to

alter the overall ratios.

The GHN type apart from closing 1st to 2nd gear, the ratios are

wider than the standard which would reduce acceleration!  I

understand that five engagement dogs are used to engage the

gears.  For fast riding/racing three are normal as this gives

fast gear changes but a slight increase in transmission swatch.

Standard box with Nova 1st gear :  This will give a first gear

which is more usable than the standard ratio and still retain the

high top gear for less frantic cruising....

Yours Truly

Graham Dyson”


Here is some further information I got by way of Bob Truelson:

“I was following up a lead for other factory hop-up parts that I

had caught wind of,  learned a couple of things, and chased my tail a bit


A local shop drops the hint that Suzuki had some hop up kits available

back when the stock bikes were being raced.  Hmm, hadn't heard that one.

Phone Suzuki Canada and Yoshimura Northwest.  Yosh. says that Roberto Gallina

was the only Suzuki importer (Italy) to ever get factory stuff for the RG

and then Suzuki pulled the plug on that before too long.  [this fits in well

with what Graham Dyson has said about Suzuki deciding that a cheap RGracer

was not in their best interests, since they were trying to sell RGB Mark 10's

also, for considerably more]. 

Okay.  So I pull out an article I have on what

the Gallina bike conversion was all about.

In addition to KYB forks (or optional Forcella Italia forks) several

choices of alloy wheels, AP brakes, he did some motor mods (disc valve cuts,

minor porting, etc).  Of note, he used stock crankcases, shafts, heads,

cylinders, rods, pistons, stock frame with special yokes to bring the

angle back to 24.5, and a braced/ lengthened stock swingarm.  And these bikes were raced with

good success by none other than Chili, in between his GP stints. Around '86

he entered 7 Italian TTFI races, won four of them, was second once, fell

off in the lead once, and trashed a gearbox in one (the only retirement of what

was considered a very reliable race bike). This class was traditionally

dominated by the  750 GSXR's, VFR's, Ducati's and Bimota's.

Anyway, among some of the more exotic bits such as a specially made

Italian close ratio gear box, other parts were likely sourced (at

least in part) through Suzuki: 36mm magnesium carbs, special cast rotary

valve covers, ND electronic ignition with specially made shaft that

drives a small counterbalancer (right off the RGB's) and factory exhausts (sort


Gallina made a copy of the pipes used by Franco Uncini in 1982 when

he won the world 500cc GP title for Team Gallina on an RGB.  They have a

diam. of 40mm at the cylinder, widen to 120mm and narrow to 22mm at the

silencer.  Yoshimura told me that the Italian Jolly Moto pipes are

a similar copy to these pipes - which would make sense.

The bike made 112 rear wheel horsepower and had seamless power

from 6k to 12k, and did unusually well on tight courses which should

have favoured the 4 strokes.  Gallina's bikes were priced at 14,500 UK


If you are up to it Rob K (now in Italy), maybe you could make a date

with  Roberto one day and pick his brain some more and see what he still has

lying around :- )

Bob T.



Interview with Mark Philips:

“Mark Phillips, 37 from Lincoln, is a two time British Champion who rode professionally for Loctite Yamaha and Padgetts amongst others during a nineteen year career.

Russ Henley caught up with him for us and asked him to look back over his career with us.


Mark, when did you start racing?

I started road racing in 1970 when I was sixteen on an ex John Weedon TZ250D. However, I was taking part in schoolboy motocross from the age of five.

And when did you turn professional?

It was in 1985. I signed to ride for Padgetts after I finished 2nd in the British 350 championship to Niall Mackensie.  

What was the highlight of your career?

It has to be winning the speed triple championship after a five year lay off due to a near fatal accident in 1988 at Donington Park and winning the Formula One championship in 1986.

Tell us about the accident!

It was while I was riding for Loctite Yamaha. I came up to the Melbourne Loop and couldn't stop. I ended up hitting the wall at the end of the track. It turns out that the front brake pads hadn't been fitted.

Did you ever ride the TT or the North West 200?

Yeah, I did both. I rode the TT once in 1984 on the Padgetts RG 500 lapping at 114 mph. My best ride at the North West was in 1986 when I finished 2nd to Joey again on the RG.

What would be your most memorable race?

It would have to be winning my first televised round of the Pro Am Series for RD350 YPVS machines.

Which current young riders do you rate?

I think Casey Stoner is very talented and I enjoy watching Chris Walker of course.

So what are you up to now?

Well, I finally retired last year after finishing 2nd in my last race at Thruxton. I have now opened a motorcycle clothing business on the A46 outside of Lincoln. It's in an old 'Little Chef' building and it opened officially in January. I'm also the head instructor at the Brands Hatch Leisure Race Schools.

Well thank you for taking the time to chat with me Mark.

No problem. Any time.

Interview by Russ Henley

British Superbike Champions






Matt Llewellyn ENG

Meakin Building Supplies

Ducati 955


Ian Simpson SCO

Duckhams Team Norton

Norton RFI 588


Jamie Whitham ENG

Team Fast Orange Yamaha

Yamaha YZF750SP


Jamie Whitham ENG

Team Fast Orange Yamaha

Yamaha YZF750SP


John Reynolds ENG

Team Green Kawasaki

Kawasaki ZXR750R


John Reynolds ENG

Team Green Kawasaki

Kawasaki ZXR750R


Rob McElnea ENG

Team Loctite Yamaha

Yamaha OW01


Jamie Whitham ENG

Castrol Suzuki/Team Grant

Suzuki GSX-R


Terry Rymer ENG

Team Loctite Yamaha

Yamaha OW01


Trevor Nation ENG

JPS Norton Racing

Norton RCW 588


Brian Morrison SCO

Honda UK/Murray Intl

Honda RC30


Steve Spray ENG

JPS Norton Racing

Norton RCW 588


Steve Spray ENG

JPS Norton Racing

Norton RCW 588


Darren Dixon ENG

Padgett’s of Batley

Suzuki RG500


Roger Marshall ENG

Heron/Skoal Bandit


* The full British Superbike Championship, as it exists today, was only launched as recently as 1996. Prior to that there had typically been more than one British series (see notes below) for production-based 750cc four-strokes, and then for Superbikes, with the Supercup usually regarded as the most prestigious. Before the adoption of the World Superbike formula, 500cc two-stroke machines were also eligible in TT F1, hence Darren Dixon’s 1988 title.

A clip from BSB with a few glimpses of Darren Dixon aboard the Padgett’s RG500

RG500 racing kits and trivia:

Unlike its obese, repli-racer cousin ( the RZ500) the RG500 Gamma was so lean and mean that it enjoyed considerable success on the racetrack, even against the all-conquering GSXR750.   Some work had to be done to make the bike a real competitor, however.  Read on and find out!

Here are some notes that give some insight into what happened behind the scenes with the RG500 roadbike, as it people began to aim it at the racetrack.