9 replies to this topic

[Giovanni]

A friendly greeting to all competents members of section "Motorcycle Racing Nostalgia".

I have need again of yours precious help and yours infinite competence.
In fact,I seek the technical details pertinents the beautiful and memorable motorbikes partecipants to the editions of the magnificent and prestigious GP 500cc World Championship of the years between 1989 and 1992
For the precision,the above mentioned motorbikes are those:

"HONDA NSR 500" (official motorbike)
"YAMAHA YZR 500" (official motorbike)
"SUZUKI RGV 500" (official motorbike)
"CAGIVA C589" (official motorbike partecipant to only season 1989)
"CAGIVA C590" (official motorbike partecipant to only season 1990)
"CAGINA C591" (official motorbike partecipant to only season 1991)
"CAGIVA C592" (official motorbike partecipant to only season 1992)
"NORTON NRS 588" (official motorbike partecipant to only British Grand Prix of season 1991)
"HONDA RS 500R" (motorbike used by many private riders until season 1991)
"SUZUKI RGB 500" (motorbike used by some private riders until season 1991)
"ROC-YAMAHA 500" (motorbike used by many private riders after season 1991)
"HARRIS-YAMAHA 500" (motorbike used by many private riders after season 1991)
"PATON V115C4" (artigianal motorbike partecipant to seasons between 1989 and 1992)
"FIOR C89-YAMAHA" (artigianal motorbike partecipant to only season 1989)
"ROTON" (artigianal motorbike partecipant to only Australian Grand Prix of season 1991)
"DOMINA P22" (artigianal motorbike partecipant to only Italian Grand Prix of season 1991)
"VRP" (artigianal motorbike partecipant to Grand Prix's of Japan,Italy,Spain,Germany and France of season 1992)
"PRP" (artigianal motorbike partecipant to only Australian Grand Prix of seasons 1989 and 1990)

I hope sincerely someone can help to me to find these particulars informations.

With friendship: Giovanni

Edited by Giovanni, 03 April 2011 - 14:25.

[rd500]

hi giovanni, the simplicity of the web http://en.wikipedia....rix_motorcycles

[rd500]

and also http://www.europark.com/

[Giovanni]

Hi "RD 500".

I thank you sincerely for the your kindness and for the your two message's.
Unfortunately,I did not find many technical informations in these links.
Do you know some other links?

Edited by Giovanni, 04 April 2011 - 16:41.

[havachat]

Hi giovani
i have a copy of spares list for yzr 500 as fitted to harris bikes plus gearing chart and a few photos if that helps you out

Colin

[7okai]

Hi Giovanni,

I can help a little with the PRP 500, as I had a couple of rides on it back in 1991.

The name PRP comes from the Australian frame makers PR Products. The P is for "P"eter MacMillan and the R is for "R"on Taylor, these two gentleman started the business in the late 1970's and produced aftermarket chassis, mainly for TZ Yamahas. Later on, Peter Macmillan was joined in the business by his brother Graham Macmillan. Some time later, Peter moved on to pursue other interests, but has remained involved in the motorcycle world. The chassis were produced, in Sydney, at several premises that incresed in size over a period of time. Nowadays, Graham is still doing work for racers in Australia.

In 1971, my father built a 3 cylinder 525cc Yamaha from a 350 TR2 racer and this machine made its debut at the Easter Australian Grand Prix in 1972. The 3 cylinder idea had potential for good perormance. The principle was soon copied overseas using the later model TR3 engine, and these were more successful. Ron Taylor and Graham MacMillan produced a watercooled 3 cylinder version of this using TZ350A engine components and housed it in a purpose built steel tubed chassis. Ron competed with the bike with some success in Australia.

Later, after we had experimented with reversing the cylinder block on our 250 and 350 Yamaha TZ's, Graham developed a new set of crankcases and gearbox that used the advantages of the reverse cylinder application. A completely new chassis was manufactured in aluminium alloy. Although not a "Deltabox" design, the chassis was of the twin spar type and used a linkage rear susension system. The rear suspension unit was White Power and the front forks were Marzocchi. The 3 Mikuni 38mm powerjet carburettors were mounted in front of the engine. 2 of the exhaust pipes exited directly backwards, and were crossed over, in the style of the Honda RS500 under the seat cowling. The third exhaust pipe was routed to exit under the bike in the more traditional manner.

The bike was never tested on a dyno and estimates of around 100~110hp would be reasonable. One of the problems that the bike suffered from was the availability of a better ignition system than the standard Hitachi unit that was used. Also, because of this, it was difficult to adjust the carburettors to give the ideal throttle response and this always affected ultimate prformance in an adverse manner. The ultimate performance potential was never realised, yet even with the modest state of tune the performance was adequate.

My experience on the bike was in the middle of our winter, at Winton raceway. The temperature over the weekend was around 13~14C. This helped to mask the overly rich carburettor settings and the bike was running reasonably crisply. So much so, in fact, that the Clerk of the Course, Ray Le Nevez made the comment that it was the fastest that he had ever seen the bike at a race meeting. I must say that I thoroughly enjoyed my time in the saddle. A month or so later, at a much warmer but wet Eastern Creek meeting the bike was back in the hands of the regular rider Greg Drew. The weak ignition and the rich mixture made it almost impossible to start, and when it was running, it was much too rich.

The 2 riders that competed on the bike were Ron Sumskis and Greg Drew. Maybe somewhere, buried away in the archives, there are some pictures of the bike. If I find some, I will add them to the thread for you. I hope that this information is of some help to you Giovanni.

Edited by 7okai, 25 April 2011 - 08:45.

[Giovanni]

Hi courteous and really competent "7okai".
Many sincere thanks for the your kind reply,as well as,obviously,for the all very interesting informations pertinent's the story of the "PRP".
These all informations are very importants for me.

With sincere gratefulness: Giovanni

[Giovanni]

Hi giovani
i have a copy of spares list for yzr 500 as fitted to harris bikes plus gearing chart and a few photos if that helps you out

Colin

Hi Colin and infinite thanks for the your cordial message.
You could publish please the your technical information pertinents the Yamaha YZR 500 and the Harris-Yamaha 500?

[havachat]

message me on here with your address and i will post you photo copies

Colin

[rotrax]

Hi Giovanni,

I can help a little with the PRP 500, as I had a couple of rides on it back in 1991.

The name PRP comes from the Australian frame makers PR Products. The P is for "P"eter MacMillan and the R is for "R"on Taylor, these two gentleman started the business in the late 1970's and produced aftermarket chassis, mainly for TZ Yamahas. Later on, Peter Macmillan was joined in the business by his brother Graham Macmillan. Some time later, Peter moved on to pursue other interests, but has remained involved in the motorcycle world. The chassis were produced, in Sydney, at several premises that incresed in size over a period of time. Nowadays, Graham is still doing work for racers in Australia.

In 1971, my father built a 3 cylinder 525cc Yamaha from a 350 TR2 racer and this machine made its debut at the Easter Australian Grand Prix in 1972. The 3 cylinder idea had potential for good perormance. The principle was soon copied overseas using the later model TR3 engine, and these were more successful. Ron Taylor and Graham MacMillan produced a watercooled 3 cylinder version of this using TZ350A engine components and housed it in a purpose built steel tubed chassis. Ron competed with the bike with some success in Australia.

Later, after we had experimented with reversing the cylinder block on our 250 and 350 Yamaha TZ's, Graham developed a new set of crankcases and gearbox that used the advantages of the reverse cylinder application. A completely new chassis was manufactured in aluminium alloy. Although not a "Deltabox" design, the chassis was of the twin spar type and used a linkage rear susension system. The rear suspension unit was White Power and the front forks were Marzocchi. The 3 Mikuni 38mm powerjet carburettors were mounted in front of the engine. 2 of the exhaust pipes exited directly backwards, and were crossed over, in the style of the Honda RS500 under the seat cowling. The third exhaust pipe was routed to exit under the bike in the more traditional manner.

The bike was never tested on a dyno and estimates of around 100~110hp would be reasonable. One of the problems that the bike suffered from was the availability of a better ignition system than the standard Hitachi unit that was used. Also, because of this, it was difficult to adjust the carburettors to give the ideal throttle response and this always affected ultimate prformance in an adverse manner. The ultimate performance potential was never realised, yet even with the modest state of tune the performance was adequate.

My experience on the bike was in the middle of our winter, at Winton raceway. The temperature over the weekend was around 13~14C. This helped to mask the overly rich carburettor settings and the bike was running reasonably crisply. So much so, in fact, that the Clerk of the Course, Ray Le Nevez made the comment that it was the fastest that he had ever seen the bike at a race meeting. I must say that I thoroughly enjoyed my time in the saddle. A month or so later, at a much warmer but wet Eastern Creek meeting the bike was back in the hands of the regular rider Greg Drew. The weak ignition and the rich mixture made it almost impossible to start, and when it was running, it was much too rich.

The 2 riders that competed on the bike were Ron Sumskis and Greg Drew. Maybe somewhere, buried away in the archives, there are some pictures of the bike. If I find some, I will add them to the thread for you. I hope that this information is of some help to you Giovanni.

Hi, In the dim and distant past the Kawasaki works team were based adjacent to my mechanic training facility in Slough, 400 yards from the Deal Avenue HQ. Kork Ballington was the jock,with his brother Derek or "Dozy" usualy around. Stuart Shenton and Stewart Baldwin were engineers under that wonderful Japanese gentleman Ken Suzuki. The KR500 four was very quick but unreliable. I was trusted to keep quiet and picked up bits and pieces through just being around before and after GP's. Towards the end of its development the answer was available in computerised ignition with knock sensors that picked up detonation and backed off the timing so avioding overheating and internal damage. Unfortunatly it was too late for the project which was scrapped shortly after the answer was available. C'est la vie! I used to chuckle at the little notes the two Stewarts would write on gaffer tape stuck on the tank-for example "Here's a message from the lads-watch the brakes-new pads!" Happy days.