Joined Feb 2007
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Rovrum S,Yorks Eng
WSBK 2011 Rule Changes Include An End To Aprilia's Gear-Driven Cams
Submitted by David emmett on Sat, 2010-07-31 21:33. As is common at world championship motorcycle racing events, the Superbike commission - the World Superbike series' rule-making body - gathered to discuss rules to be introduced for the 2011 series. After the meeting, a press release was issued detailing the changes to be made for next season, and they make interesting reading.
The biggest change was the scrapping of the loophole which has allowed Aprilia to drive the camshafts on their RSV4 World Superbike machines using gears instead of the chains fitted on the production bikes. The rule had originally read "The method of cam drive (chain, belt or gears) must remain as on the homologated motorcycle unless a complete kit is available through normal commercial channels" but the last part of the sentence - "unless a complete kit is available through normal commercial channels" - has been dropped.
Aprilia's use of gear-driven cams has been controversial from the start. The original cylinders are supplied with the machining required to fit the gear drive as standard, but use a chain drive to keep production costs down. The Aprilia's V4 configuration makes this even more costly, requiring two sets of gears for each bank of cylinders, and so fitting gear-driven cams to the road bike would add considerably to the basic price. Fitted as an aftermarket race kit, the gear-driven cams allow the RSV to attain higher revs and allow for more precise cam timing. The RSV4 has been fast from the start of the season, but since the Alitalia Aprilia started using the gear drive, the disparity with the other bikes has grown.
To put an end to the arguments, the Superbike Commission has prohibited fitting aftermarket kits, and all World Superbike machines must use the cam drive fitted as standard. Of course, this does not prevent Aprilia from using gear-driven camshafts completely, but it does require that the RSV4 be sold with the gear drive as standard, something which Aprilia may be less keen to do.
Two other notable changes are to be made for 2011. The first is the banning of a 2nd bike for the World Supersport class, bringing it into line with the 125cc and Moto2 support classes in MotoGP. The rule is aimed at cutting costs, as having a single bike complete with spares to repair it prepared to race is still cheaper than having two complete bikes. The rule hopes to remove the advantage that the wealthier teams such as Ten Kate Honda and Parkalgar Honda have over the mid-pack riders.
The final change of note is the rescheduling of practice on Friday. Activities had been cut back on Friday morning as a cost-cutting measure, but instead of losing practice, the remaining practice sessions were just squeezed together on Friday afternoon. With the restoration of on-track action on Friday morning, a more relaxed schedule can be followed, and the World Supersport class can get some practice on track at around the time they will be racing on Sunday, a complaint that was commonly heard from the WSS teams. The measure never really cut costs, as teams had to arrive at the track by Thursday at the latest anyway, and would sit twiddling their thumbs on Friday morning, waiting to hit the track at noon. A similar measure is to be tried in the MotoGP series at Aragon, when the schedule will revert to four sessions of practice, including one on Friday morning
motomatters
Submitted by David emmett on Sat, 2010-07-31 21:33. As is common at world championship motorcycle racing events, the Superbike commission - the World Superbike series' rule-making body - gathered to discuss rules to be introduced for the 2011 series. After the meeting, a press release was issued detailing the changes to be made for next season, and they make interesting reading.
The biggest change was the scrapping of the loophole which has allowed Aprilia to drive the camshafts on their RSV4 World Superbike machines using gears instead of the chains fitted on the production bikes. The rule had originally read "The method of cam drive (chain, belt or gears) must remain as on the homologated motorcycle unless a complete kit is available through normal commercial channels" but the last part of the sentence - "unless a complete kit is available through normal commercial channels" - has been dropped.
Aprilia's use of gear-driven cams has been controversial from the start. The original cylinders are supplied with the machining required to fit the gear drive as standard, but use a chain drive to keep production costs down. The Aprilia's V4 configuration makes this even more costly, requiring two sets of gears for each bank of cylinders, and so fitting gear-driven cams to the road bike would add considerably to the basic price. Fitted as an aftermarket race kit, the gear-driven cams allow the RSV to attain higher revs and allow for more precise cam timing. The RSV4 has been fast from the start of the season, but since the Alitalia Aprilia started using the gear drive, the disparity with the other bikes has grown.
To put an end to the arguments, the Superbike Commission has prohibited fitting aftermarket kits, and all World Superbike machines must use the cam drive fitted as standard. Of course, this does not prevent Aprilia from using gear-driven camshafts completely, but it does require that the RSV4 be sold with the gear drive as standard, something which Aprilia may be less keen to do.
Two other notable changes are to be made for 2011. The first is the banning of a 2nd bike for the World Supersport class, bringing it into line with the 125cc and Moto2 support classes in MotoGP. The rule is aimed at cutting costs, as having a single bike complete with spares to repair it prepared to race is still cheaper than having two complete bikes. The rule hopes to remove the advantage that the wealthier teams such as Ten Kate Honda and Parkalgar Honda have over the mid-pack riders.
The final change of note is the rescheduling of practice on Friday. Activities had been cut back on Friday morning as a cost-cutting measure, but instead of losing practice, the remaining practice sessions were just squeezed together on Friday afternoon. With the restoration of on-track action on Friday morning, a more relaxed schedule can be followed, and the World Supersport class can get some practice on track at around the time they will be racing on Sunday, a complaint that was commonly heard from the WSS teams. The measure never really cut costs, as teams had to arrive at the track by Thursday at the latest anyway, and would sit twiddling their thumbs on Friday morning, waiting to hit the track at noon. A similar measure is to be tried in the MotoGP series at Aragon, when the schedule will revert to four sessions of practice, including one on Friday morning
motomatters
