Midget brakes in good, well adjusted condition are balanced and well suited to the weight and tyre size of the car. If you are experiencing brake fade in spirited use over your favourite mountain pass, then changing the pad material is a good first step.
Take a look in our shop for our range of brake pads that fit standard and the 9” front brake conversions.
We stock a range of Maniflow exhaust manifolds and systems for both ‘A’ series and Triumph engined Spridgets.
The best set up for your own car is dependent on the specification of the engine and its intended use.
Take a look in our shop for our range of exhausts components to suit your intended use
3J NXG Limited Slip Differentials.
These are fully locking differentials, where in the event of one driven wheel being airbourne, the drive will be transferred to the other wheel.
Torque biasing differentials, (Quaife ATB etc) use the torque difference across the axle to regulate drive, however if one wheel is airbourne (and hence has no discernable torque through the tyre contact patch) it allows the airbourne wheel to spin and not drive.
A brief description and explanation of the different ramp angles and presets available:
The first number is the ramp angle that the pawl acts against under drive/acceleration. The larger the number the steeper the angle which slows the locking action.
The second number is the angle/slope the pawl faces under deceleration/braking. In most situations this is 90 degrees or a right angle, so the differential does not lock up under braking.
There are some motorsport disciplines where locking under braking is desirable, such as loose surface rallying or drifting, where a reverse flick and destabilising the rear is used to aid turn in. In this situation a 40/40 ramp angle might be more suitable.
50/90 Ramp angle 25-35lb preset. This is a fast road set up that is more progressive and gentle in operation.
40/90 Ramp angle 35-45lb preset. Fast road, hillclimb use. This is the most common set up for roadgoing Sprites using 5” or 6” rims with treaded road legal tyres.
30/90 Ramp angle 65-75lb preset. Race use or competition use using slicks or very sticky list 1b 1c tyres. Avon ZZR, ACB10, AO48, R888 etc. Also used in some loose surface events where a faster more aggressive locking action is required.
A car used primarily for road/touring is probably better with a Torque biasing LSD as they are quiet in operation and are generally fit and forget. (Allowing for regular oil changes).
More competition focussed cars are generally better with a fully lockable LSD, they do require more maintenance as the clutch faces wear, and they do sound like a bag of spanners at slow speed with steering lock applied!.
The 3J LSD are adjustable, the different ramp angles are machined into a steel carrier within the unit, which can be unbolted and moved around to the position
Take a look in our shop for our range of transmission components to suit your intended use
Wheels and Tyres
Original 13” diameter wheels for Midgets and Sprites come in three widths:
- 3.5J Original Steel wheel on Frogeye, Mk 2/3 Sprites, early Midget.
- 4J Wire wheel option throughout production.
- 4.5J Early and Late style Rostyle.
Tyres fitted were 5.20 Crossply and then 145 82 now 80 profile radials.
A common option is to use 155/80 or 155/70 series tyres, with Uniroyal Rain Expert being one of my favourites for everyday use. You can use 165/70 on the 4.5J rim which retains the same overall gearing as the original tyres.
Various alloy wheels are available for Spridgets with Minilite and Revolution being the most popular.
Widths suitable for roadgoing cars without wheel arch modifications are 5” or 5.5” and at a push 6” for round wheel arch cars.
Finding a tyre suitable for fast road and track day use is difficult, as bespoke track tyres such as Yokohama AO48, Toyo, Nankang etc tend to be compromised in wet grip, uncomfortable and tramline in everyday useage, although they grip well on smooth hot tarmac !.
If you can find them, Avon CR500 in 175/55 13 give excellent track performance, with very good wet weather grip. These were developed by Avon Racing to fit the original Caterham Superlite. So are a lightweight construction, with a reasonably compliant sidewall and rubber compound ideally suited for the weight of a Spridget. (Try BMTR or Caterham Cars for stock).
Take a look in our shop for our range of wheels.