LOT 434
The property of the late John Renwick 1950/1951 Vincent 'Prometheus' 1,248cc Series-C Rapide Sidecar Racing Motorcycle Registration no. not registered Frame no. RC7471 Engine no. F10AB/1/7002
Sold for £16,100 inc. premium
Lot 434
The property of the late John Renwick, 1950/1951 Vincent 'Prometheus' 1,248cc Series-C Rapide Sidecar Racing MotorcycleRegistration no. not registered Frame no. RC7471 Engine no. F10AB/1/7002
The Autumn Sale - The Classic Motorcycle Mechanics Show, Stafford|9 October 2021, 12:00 BST|Stafford, Staffordshire County Showground
The property of the late John Renwick
1950/1951 Vincent 'Prometheus' 1,248cc Series-C Rapide Sidecar Racing Motorcycle
Registration no. not registered
Frame no. RC7471
Engine no. F10AB/1/7002
1950/1951 Vincent 'Prometheus' 1,248cc Series-C Rapide Sidecar Racing Motorcycle
Registration no. not registered
Frame no. RC7471
Engine no. F10AB/1/7002
• Highly successful Vincent racing outfit
• Stellar performance
• Built, raced, and maintained by John Renwick
In 1982, just a few years after John Renwick turned his back on modern sidecar racing following the FIM's 1976 ban on hub-centre steering and other innovations, Prometheus emerged from John's workshop to contest classic sidecar racing. The chair was detachable, and wheels were 16" fore and aft, with a 12" wheel on the sidecar. Prometheus has a capacity of 1,248cc from bore and stroke dimensions of 90mm x 98mm, and generates 102 bhp at 6,500 rpm at the back wheel on high octane petrol. This is considerably more than double the original power output of the 1951 Series-C Rapide on which it is based. At the heart of the engine is John's own crankshaft with bob weights and Carillo rods. The standard Vincent crank uses full circle flywheels and a pressed steel crankpin pulled up tight with a large nut at both ends. The nuts are recessed and therefore the pressed portions are relatively short. By contrast the Renwick crank is permanently pressed under 30 tons of hydraulic pressure. The 1½" diameter pin is in EN36 steel and is a .006" interference fit in the EN24T "wheels". The mainshafts are machined oversize and then ground to size after assembly. The gearbox has a Quaife five speed cluster as originally commissioned by John Surtees.
Having been progressively developed through the mid-eighties, Prometheus won the first six races of the 1987 season with John Renwick in the pilot's seat and Micky Carter in the sidecar, but in practice at Donington Micky fell from the chair, and in the ensuing crash John broke an arm and a leg. Following his recovery, a double win was achieved at Snetterton in 1989, but outings were only sporadic through the nineties. At Mallory Park's Sidecar Festival in October 1998, with Peter Branton in the sidecar, the result was a win. In the late 1990s John sprinted Prometheus at The Brighton Speed Trials with a best time of 13.9 seconds but finishing second to Dave Goddard's long wheelbase Suzuki outfit was the spur to the creation of Epimetheus, the next chapter in the story. When Prometheus was first built the cut-off date for visible components was 1958, so Vincent drum brakes were fitted all round, but as the cut-off date moved forwards, components were upgraded accordingly, including the fitting of hydraulic disc brakes to the front and rear wheels. In 2005 Prometheus ran at the Goodwood Festival of Speed, and then most recently in 2006 at the Sidecar Festival, Pukekohe, New Zealand. After a period of inactivity re-commissioning will be required before further use. Prospective bidders should satisfy themselves as to the motorcycle's completeness and mechanical condition.
• Stellar performance
• Built, raced, and maintained by John Renwick
In 1982, just a few years after John Renwick turned his back on modern sidecar racing following the FIM's 1976 ban on hub-centre steering and other innovations, Prometheus emerged from John's workshop to contest classic sidecar racing. The chair was detachable, and wheels were 16" fore and aft, with a 12" wheel on the sidecar. Prometheus has a capacity of 1,248cc from bore and stroke dimensions of 90mm x 98mm, and generates 102 bhp at 6,500 rpm at the back wheel on high octane petrol. This is considerably more than double the original power output of the 1951 Series-C Rapide on which it is based. At the heart of the engine is John's own crankshaft with bob weights and Carillo rods. The standard Vincent crank uses full circle flywheels and a pressed steel crankpin pulled up tight with a large nut at both ends. The nuts are recessed and therefore the pressed portions are relatively short. By contrast the Renwick crank is permanently pressed under 30 tons of hydraulic pressure. The 1½" diameter pin is in EN36 steel and is a .006" interference fit in the EN24T "wheels". The mainshafts are machined oversize and then ground to size after assembly. The gearbox has a Quaife five speed cluster as originally commissioned by John Surtees.
Having been progressively developed through the mid-eighties, Prometheus won the first six races of the 1987 season with John Renwick in the pilot's seat and Micky Carter in the sidecar, but in practice at Donington Micky fell from the chair, and in the ensuing crash John broke an arm and a leg. Following his recovery, a double win was achieved at Snetterton in 1989, but outings were only sporadic through the nineties. At Mallory Park's Sidecar Festival in October 1998, with Peter Branton in the sidecar, the result was a win. In the late 1990s John sprinted Prometheus at The Brighton Speed Trials with a best time of 13.9 seconds but finishing second to Dave Goddard's long wheelbase Suzuki outfit was the spur to the creation of Epimetheus, the next chapter in the story. When Prometheus was first built the cut-off date for visible components was 1958, so Vincent drum brakes were fitted all round, but as the cut-off date moved forwards, components were upgraded accordingly, including the fitting of hydraulic disc brakes to the front and rear wheels. In 2005 Prometheus ran at the Goodwood Festival of Speed, and then most recently in 2006 at the Sidecar Festival, Pukekohe, New Zealand. After a period of inactivity re-commissioning will be required before further use. Prospective bidders should satisfy themselves as to the motorcycle's completeness and mechanical condition.
Footnotes
As with all Lots in the Sale, this Lot is sold 'as is/where is' and Bidders must satisfy themselves as to the provenance, condition, age, completeness, and originality prior to bidding.
'Prometheus' in the rain at Cadwell Park 1987
Additional information
Looking for a similar item?
Our Motorcycles specialists can help you find a similar item at an auction or via a private sale.
Find your local specialistAuction Viewings
- 9 October 2021, 09:00 - 17:00 BST
- 10 October 2021, 09:00 - 17:00 BST
