|1977 - 1979||
In 1976 Suzuki started to develop a larger version of the RG500, the XR23, better known as the RG700. This bike was a big bore (62mm) XR22 with an engine capacity of 652cc. The bike was more or less an riding test lab for future RG's. By building a bike with a bigger and more powerfull engine Suzuki could test components for the RG500's of the future. In the beginning the bike was too powerfull and had to be de-tuned to 135 bhp. Knowing that the RG500 would be as powerfull as the XR23, Suzuki could start to test and develop parts for their future 500cc bikes.
The XR23 was the first bike to have an engine with the "stepped" cylinder layout , this lowered the centre of gravity and improved cooling of the engine. The gearbox was designed like a "cassette" to enable transmission change in 20 minutes. These engine and gearbox layout-design was first used on the XR23, and later on the XR22 (RGA500).
In 1978 Suzuki came with the XR23B. The best way to recognise a XR23B is by looking at the seat fairing. This was widend on both sides to host the expansion chambers. In 1978 Japan came with new exhausts for the XR23 but the problem with the rear cylinder's exhausts was that the exhaust pipes were not allowed to stick out behind the rear wheel ad. Since a 652cc engine needs different expansion chambers and bigger silencers then a 500cc engine, Suzuki chose to curve the expansion chambers. The problem with this exhaust layout was; the seat got too hot and your boots would burn. Later Barry Sheene would use the old exhausts on his RG700, this way he lost some of the power but the bike was better to drive.
Steve Parrish said that a better name for the bike was the "collarbone crusher" since this happend to him and Tom Herron at Donnington park within 10 seconds from eachother. Only Sheene loved to ride the XR23, Hennen, Parrish, Herron and Hartog hated the bike. The bike was overpowered and shorter then the RG500, even in 4th gear it would lift its front wheel. The weight distribution was awfull and to prevent the bike from lifting its front wheel Parrish used to hung a big piece of cast iron over the front exhaust curve, they also made one for Sheene because he would pinch Parrish's one. This was all to the disgust of the Japanese, as Sheene said; " The Japs went bloody bananas" . Japan spent loads of money to reduced the bikes weight by using magnesium and titanium and what did the British? They bolted a big piece of lead on the bikes to make it handle properly. The Japs also weren't that pleased when Sheene fitted the old type of exhausts back on the bike. But the thing was, the bike was overpowered any way, and with the old type exhausts there was still plenty of power without burning your boots and your bum.
Since the bike was pure for testing, Suzuki never planned to use the bike in the F750 championship because for the F750 homologation it would have been nesseccary to build at least 25 street versions of the bike. Suzuki only built four RG700 bikes to use them in the Trans Atlantic "Open Class" Match Races and later for the British Superbike class. Sheene gave the bike it's first win. In 1979 the FIM announced the last season for F750 and dropped the homologation rule, this made it possible to race the XR23B on world level and Virginio Ferrari rode his Team Gallina XR23B to a win in the bike's first F750 race.
|XR23 Sheene, with normal exhausts|
|Hartog on a XR23|
|Suzuki XR23B "Pregnant Duck"|
|XR23B Virginio Ferrari|
|Hartog on a XR23B|
|Pat Hennen fighting his XR23B|
|The "bulky" rear|