MED INLINE STRAIGHT CUT GEAR KIT
Our straight-cut close-ratio gear set for the inline gearbox (Sprite and Midget) is machined on the very latest CNC machinery allowing us to offer a perfect gear tooth form. As with all of our gear sets, these are made locally in the Midlands so we can keep a constant eye on quality control.
The gear kit is produced from EN36C and case hardened along with molybdenum-sprayed baulk ring faces.
Ratios are as per the original Special Tuning gearsets, making these an ideal choice for fast road and light competition transmissions.
- Laygear cluster
- Second gear
- Third gear
- First motion - input gear
- First - 2.573:1
- Second - 1.722:1
- Third - 1.255:1
- Fourth - 1:1
Please see the additional information tab for more detail.
Straight-cut vs helical-cut gears
The design of helical-cut gears, as found in standard gearboxes, leads to increased side (or axial) loadings on the transmission. As power outputs increase, this places greater strain on the transmission casing and bearings, in-turn leading to reduced reliability.
Using straight-cut gears allows us to design a stronger transmission within the standard casing. It also reduces power losses to make the most of the engine's power. We estimate between 5-7bhp can be gained at the wheels by using a straight-cut gearset.
There is a myth that driving with a straight-cut gearbox on the road is hard work. In fact a straight-cut synchromesh gearbox is no different in operation to a regular gearbox, but it will be louder.
Most cars use a straight-cut first/reverse gear; it is the swap to a dog-engagement racing gearset that will affect the drivability of a road car.
Closer ratios give a reduced engine RPM drop when changing up a gear. This keeps the engine within its optimum power band more effectively, resulting in better acceleration through the gears. Fourth gear is still the same 1:1 ratio, but first gear tends to be taller than with a standard gearset, to bring the ratios closer together.
The final drive ratio and wheel size need to be carefully considered to give the best results - contact us if you're unsure.