Transmission.

I have been talking to Nova Racing Transmissions Ltd. about the prospect of them manufacturing a revised Transmission for the Gamma. Nova used to make transmissions for the Gamma a few years ago so have all the relevant knowledge on the RG500.
Here's a copy e-mail from Randy Norian's files after talking with Nova

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 1986.

This was too much for the organisers, who then abandoned the formula in favour of an all four stroke class.

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 disengaged.

My own personal view of the above id 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.

Depending on there being sufficient demand, I intend to produce a batch of ten minimum transmission sets as follows:-

A dry clutch kit, complete with gearbox input shaft, 1st gear output and kick start / oil pump gear. This to raise the ridiculously low 1st gear, but retain all the remaining standard gears.

The specification to include the following:-

Input shaft with associated 1st gear and kick start / oil pump gear, straight cut primary gear set, magnesium clutch case and operating cover (you will require the rack and pinion shaft from your standard clutch) clutch outer drum with driving plate.

Incorporating a "cush drive" clutch hub, pressure plate and all new bearings and seals. A set of sintered bronze and steel
clutch plates (similar to the RGB racer). All fittings and bolts are in stainless steel, all alloy parts anodised and coloured
black, the magnesium cover being black chromate finish.

The following is a comparison in percentage terms of the gear ratios relevant to the Suzuki RG Gamma.

Standard G.box Nova/RGBType GHN Std & Nova 1st Gear

1st
33.6% 28.2% 23.46% 25%
2nd
21.14% 18.75% 18.34% 21.14%
3rd
15% 11.36% 14.83% 15%
4th
10.9% 7.8% 12.6% 10.9%
5th
8.5% 5.87% 9.63% 8.5%
6th

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

Observations:
The standard road gearbox has, apart from 1st gear, acceptable ratios.

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.

Nova Close Ratio: If demand is sufficient then we will produce a batch of gear sets. The ratios will be similar to the RGB and will incorporate 3 undercut engagement dogs for positive selection, note the standard box is only undercut on the input shaft.

So there's a bit of history regarding Nova's involvement with the RG500.
I have a few options available to myself and these are as follows.

GEARBOX

Nova designed gearset with higher ratio 1st gear and matching kickstart/oil pump drive gear supplied assembled ready to fit

The input shaft for wet clutch and dry clutch installations are not interchangeable and the appropriate type must be identified when ordering. There will be no difference in cost for either type. However if the customer wishes to update to a dry clutch then a dry clutch input shaft is required

Gearbox only �1250.00 Sterling

DRY CLUTCH

Nova designed and developed from the original F1 racer. Comprises clutch cover and operating cover cast in magnesium alloy - straight cut primary gearset - clutch drum assembly with hard anodised aluminium clutch drum featuring a cush drive - clutch hub assembly in hard anodised aluminium with steel back plate - pressure plate with stainless fittings and bearings. All necessary bearings, seals and clutch plates are readily available parts. All fittings are in stainless steel to avoid corrosion. The standard clutch operation is retained.

Clutch only �950.00 Sterling

INPUT SHAFT

For use with standard gearbox but with extended length for Nova Dry Clutch. Also includes high 1st gear and kick-start/oil pump gear

Price �400.00 Sterling

All prices exclude VAT at the current rate

So there you go, I need a minimum of 10 units to order as this is the minimum manufacturing quantity.
Obviously there is a choice whether to go for the dry clutch and gearbox or just the gearbox, this is up to you to decide.
If you are interested please mail me [email protected] with your requirements.

I'm going to keep a table on this page of the results so far, as this might influence your choice.

Question or comments? please mail Mark

[email protected]

or

[email protected]