Bonhams Motorcycle Department’s ‘Summer Sale’ will take place in the incredible surroundings of Bicester Heritage, Oxfordshire, on 14-16 August. The sale will be on view in the 50,000 sq ft former RAF Bomber Station hangar at Bicester Heritage, with pre-sale viewing on the 13 & 14 August by appointment. The sale features more than 580 lots and will take place over three days, with a sale of the Spares and Memorabilia (including The Morbidelli Collection Spares and Memorabilia) on Friday 14 August. The motorcycles from the The Morbidelli Collection will be offered on Sunday 16 August.

Department Director, Ben Walker commented; “Bicester Heritage is a fitting backdrop for what is set to be a truly memorable sale with a brand new live and online auction format. Bonhams inaugural Live & Online Motoring Auction on Saturday 30 May at Bicester Heritage clearly demonstrated the appeal and appetite for this auction format and we saw a significant increase in bidder registrations. The sale total exceeded £2million and had a combined sell-through rate of 80%. 100% of all motorcycles sold to new owners, 82% selling above top estimate.”

One of the highlights of the sale is an ultra-rare 1975 Suzuki 750cc XR11 Formula 750 Racing Motorcycle ridden to victory in the 1976 Isle of Man Classic TT by Texaco Heron Team Suzuki works rider John Williams. It has an estimate of £42,000-48,000. The bike represents the final development of Suzuki XR11 Formula 750 racer (also known as the TR750). Initially dubbed the ‘Flexy Flier’ on account of its wayward handling, it was an XR11 that Barry Sheene was riding when he had that famous Daytona crash in 1975 – though that was notably caused by a tyre failure rather than any inherent deficiency in the machine.

The XR11 had been developed from the GT750 roadster for the increasingly popular 750-class racing. For its 750 racer, Suzuki up-rated the GT750 engine with different cylinders, a dry clutch and magnesium castings; they also developed an entirely new lightweight frame, and it was this that would prove the XR11’s Achilles Heel. Made from tubing that was too small in diameter, it flexed under power, hence that famous sobriquet. Maximum power was raised from an initial 100bhp in 1972 to 116bhp for 1975 in the XR11’s final incarnation. By this time the frame had undergone several revisions to strengthen it, and for 1975 the chassis was further updated with an XR14 (RG500) swinging arm and lay-down shock absorbers. At last the XR’s handling was no longer a handicap, as evidenced by John Williams’ Isle of Man TT victory in ’76. Indeed, John had made history in the Senior race by setting the first 110mph lap of the Mountain Circuit and repeated that feat on board his XR11 in the Classic race.

Born in 1946, John Williams made his racing debut in 1964 and progressed through club racing ranks to make his Isle of Man debut in the Manx Grand Prix in 1966. Williams swiftly established a reputation as a public roads specialist, securing his first IoM win in the 1971 500 Production TT. John would go on to win a further three TTs and score nine podium finishes. He was sponsored by Tom Arter and then Gerald Brown before signing for Texaco Heron Team Suzuki for 1976, joining Barry Sheene and John Newbold.

Records show that the machine offered here is a 1975 model, first used by the Suzuki works team in the USA, which was despatched to the UK at the end of the ’75 season together with the team’s equipment when it pulled out of racing. Suzuki’s American works riders for 1975 had been Dave Aldana and Pat Hennen. According to former Texaco Heron Team Suzuki race engineer Nigel Everett (letter on file), ‘GT750-62865’ (the last of the frame number sequence) was assigned to works rider Percy Tait in 1976 for use in Formula 750 events – and it is believed this is the machine Percy won the 750 Class in the 1976 North West 200 on – before being allocated to John Williams halfway through the season.

Texaco Heron Team Suzuki did not campaign the XR11s after 1976 and the bikes were disposed of, this example being sold to Percy Tait on 4th November ’76 (the Percy Tait Racing stickers are still on the fairing). By this time Percy had retired from racing (following a serious accident in the Isle of Man Production TT in 1976) and become a Suzuki dealer. It is not known whether or not Percy sponsored another rider on the XR11.

The current vendor, a motorcycle racing enthusiast with an important private collection, saw this XR11 advertised in MCN in the early 1980s and purchased it from the owner, a garage proprietor in Leominster. The Suzuki has been kept as part of his collection since then and is presented in wonderful ‘as last raced’ condition. Ex-factory machines of this pedigree – original and unmolested – rarely come to the market, making this ultra-rare and historic TT-winning XR11 of exceptional interest to collectors.

The sale will be a Live ‘Behind-Closed-Doors’ auction. The auctioneer will be present on the rostrum as usual, and bids will be accepted in the following formats: online, on the phone, or by leaving an absentee bid. All bidding will be conducted remotely via a live stream online and in accordance with the latest government guidelines. Pre-sale viewing of all lots is by appointment only. Live and interactive video condition reports and enhanced online ‘walk around video’ content will be available for bidders.

The sale is not taking place at The Stafford County Showground following the recent announcement that The International Classic MotorCycle Show, scheduled for the 15 & 16 August, has been cancelled.