Semi-Helical 5 Speed Gearbox - Used
Type 9 Semi-Helical gearbox to suit all Duratec de-Dion Caterhams and others. This box has covered 100 miles since rebuild with new gearset. New price £2200.
What the manufacturers say…
The gear tooth profiles are much larger than ford original specification and are similar to a typical straight cut gear. The amount of engine torque this gear kit can be used with is greater than a typical s/cut gear kit. The gears are cut to a angle of 25 degree's, this reduces end thrust friction but still maintains more than one tooth driving at any one time, this is obviously stronger than one at a time as in s/cut gearboxes but also 95% quieter. The gears are fully shaved after gear cutting to perfect the gear form. First and second gear are bored out much larger than standard and in other areas the gear kit is also lightened. The benefit of reduced mass is enhanced synchro life and a faster, lighter gear change. First and second gears are fitted with caged needle roller bearings to reduce friction.
It has been lightened where possible and weighs 1.112 kg less than a standard ford helical gear kit (7.840kg).
The lighter the gear kit the less load there is on the sychromesh, therefore increasing reliability.
The gear ratios are as follows 1st 2.29, 2nd 1.61, 3rd 1.225, 4th 1:1, 5th .87
These gear ratios we believe to be optimum for most applications where the vehicle is used on the road and for competition use. The ratios are very similar to the ratios Ford used for their Rocket helical gear kit from the 70`s. A gearbox is a torque multiplier, the more torque you have the less gears and gear changing you need to do. Six speed gear boxes with very close ratios are ideal for small capacity engines with very narrow power bands, you need to use as much torque as possible before changing gear.
Type 9 Semi-Helical gearbox to suit all Duratec de-Dion Caterhams and others. This box has covered 100 miles since rebuild with new gearset. New price £2200.
What the manufacturers say…
The gear tooth profiles are much larger than ford original specification and are similar to a typical straight cut gear. The amount of engine torque this gear kit can be used with is greater than a typical s/cut gear kit. The gears are cut to a angle of 25 degree's, this reduces end thrust friction but still maintains more than one tooth driving at any one time, this is obviously stronger than one at a time as in s/cut gearboxes but also 95% quieter. The gears are fully shaved after gear cutting to perfect the gear form. First and second gear are bored out much larger than standard and in other areas the gear kit is also lightened. The benefit of reduced mass is enhanced synchro life and a faster, lighter gear change. First and second gears are fitted with caged needle roller bearings to reduce friction.
It has been lightened where possible and weighs 1.112 kg less than a standard ford helical gear kit (7.840kg).
The lighter the gear kit the less load there is on the sychromesh, therefore increasing reliability.
The gear ratios are as follows 1st 2.29, 2nd 1.61, 3rd 1.225, 4th 1:1, 5th .87
These gear ratios we believe to be optimum for most applications where the vehicle is used on the road and for competition use. The ratios are very similar to the ratios Ford used for their Rocket helical gear kit from the 70`s. A gearbox is a torque multiplier, the more torque you have the less gears and gear changing you need to do. Six speed gear boxes with very close ratios are ideal for small capacity engines with very narrow power bands, you need to use as much torque as possible before changing gear.
Type 9 Semi-Helical gearbox to suit all Duratec de-Dion Caterhams and others. This box has covered 100 miles since rebuild with new gearset. New price £2200.
What the manufacturers say…
The gear tooth profiles are much larger than ford original specification and are similar to a typical straight cut gear. The amount of engine torque this gear kit can be used with is greater than a typical s/cut gear kit. The gears are cut to a angle of 25 degree's, this reduces end thrust friction but still maintains more than one tooth driving at any one time, this is obviously stronger than one at a time as in s/cut gearboxes but also 95% quieter. The gears are fully shaved after gear cutting to perfect the gear form. First and second gear are bored out much larger than standard and in other areas the gear kit is also lightened. The benefit of reduced mass is enhanced synchro life and a faster, lighter gear change. First and second gears are fitted with caged needle roller bearings to reduce friction.
It has been lightened where possible and weighs 1.112 kg less than a standard ford helical gear kit (7.840kg).
The lighter the gear kit the less load there is on the sychromesh, therefore increasing reliability.
The gear ratios are as follows 1st 2.29, 2nd 1.61, 3rd 1.225, 4th 1:1, 5th .87
These gear ratios we believe to be optimum for most applications where the vehicle is used on the road and for competition use. The ratios are very similar to the ratios Ford used for their Rocket helical gear kit from the 70`s. A gearbox is a torque multiplier, the more torque you have the less gears and gear changing you need to do. Six speed gear boxes with very close ratios are ideal for small capacity engines with very narrow power bands, you need to use as much torque as possible before changing gear.
