A steering wheel guide? Really?

Well, when I take a look at all the questions that still pop up here and there, I seem to have missed out on some steering wheel basics. I would like to make up for that today.

How to choose a steering wheel?

Diameter

Choosing the right diameter is quite important, it has the most influence on the steering effort and feel. But it also really depends on what you are doing with the car, city commuting, freeway, track, canyon carving, etc., so choose wisely (or have a spare steering wheel in the car like me most of the time).

A lot of people are in love with the 370mm diameter steering wheels. A bigger steering wheel will always lighten the steering effort at slow speeds, reducing the diameter will give the steering more feel and weight.

Most common size for cars without power steering however is 350mm, some prefer smaller ones with about 320mm, some the bigger 370mm or even 380mm steering wheels. Also a matter of personal taste.

But it also depends on the type of car of course. A rear-engine early Porsche 911 doesn’t have much weight in front so in my opinion the 350mm steering wheel has the perfect size even though the stock steering wheel was a little bigger.

Dish

The dish of a steering wheel is defined by the dimension from the mounting point to the center of the steering wheel where the rim section is attached. The bigger the dimension, the more the dish.

Most of the early Momo Steering Wheels were flat, means they had no dish like this Momo Sebring from the Mid 60s.

Semi-dished wheels are typically around 30-40mm like this Momo Prototipo. This was the most common kind of dish in the 70s, 80s, 90s and is still today very common if you look at current Momo Steering Wheels.

Deep-dished steering wheels are typically around 70-90mm. That brings the steering wheel much closer to the driver to allow more effort to be applied to the steering wheel. Great example and a steering wheel that many people love and use in their track cars is the suede Momo Mod07.

Material

Most of the vintage steering wheels have either a leather or a wooden rim. Suede became very popular over the years, especially with but not limited to vintage race cars. But there are also other materials out there such as polyurethane, carbon fibre or aluminium. 

Leather is very durable and grippy and it develops a beautiful patina over time. Great with gloves as well. Make sure you pick a period correct steering wheel for your car.

Wood has this very traditional touch, always looks period and classy in most of the vintage cars. Lasts well but wood works and can crack when in dry climates with a lot of sun exposure. Very grippy with leather gloves.

Suede is the default choice for the track or motorsport in general and gives excellent grip but it needs more care than other surfaces. Perfect with suede palm gloves. The Momo Mod 07 is a great example of such a steering wheel.

How to mount a steering wheel?

The stock factory wheel on most cars has a splined mounting which is held in place buy a single nut. Most cars. Factory wheels are made to fit a specific car, thats why they are all different and not interchangeable unlike steering wheels from Momo, Sparco, Nardi, etc.

Hub adapter

Non factory steering wheels, also referred to as aftermarket steering wheels are not specifically made for each car. For that purpose, you will need an adapter for your specific vehicle, called a hub, hub adapter, steering kit or boss kit or something similar. Find a list of available Momo Hub Adapters here

The hub fits the steering column of your vintage car and you bolt on the steering wheel onto a circle, most likely with six bolts. The hub will also have a wiring for the horn and in case your car came with an airbag, these hub adapters are equipped with an resistor to turn off the airbag warning light. Airbag removal can be dangerous, leave this to a professional. Just saying.

Most hub adapters come with a collapsible section. In case of an impact it reduced the risk of dangerous injuries. 

For some cars, the hub adapters are available in different lengths. You might choose the shorter version if you use a deep-dished steering wheel, or the longer version if you are using a flat or semi-dished steering wheel respectively.

Spacers

Especially with race or track cars, you might want to have the steering wheel a bit closer. For that purpose, there are spacers available in different lengths, like this one here which is a 50mm spacer that fits the most common bolt patterns (Momo, Nardi, Personal, Sparco, OMP, etc.)

Quick Release Kit

In a race car with a full race cage and race seats, a quick release kit is very helpful as it simplifies getting in and out of the car. Tried a lot of kits, most of them were shaky. The best one by far is the one from NRG.

Adapters

If you’re into Kremer Porsche race cars, the Jägermeister K2/K3 935 936, you might have seen the Kremer Porsche Steering Wheel made by Victor. There are just a few hub adapters available for a very limited number of cars. If you want to mount such a Kremer Porsche Steering Wheel into your Porsche 911, you can either drill holes (please don’t) or use the patipatina Victor to Momo Hub adapter.

Bolt patterns

A few people asked questions about interchangeability of hub adapters and steering wheels, e.g. if a Sparco Steering Wheel will work with a Momo Hub Adapter. Here are the most common patterns summarised. Bolt patterns consist of 2 numbers, the first is the number of bolts, the second is the pitch circle diameter, the diameter of the circle the bolts are going through.

Bolt pattern: 6 x 70mm: 
Momo, OMP, Sparco, Sabelt, Simoni, NRG, Motocorsa, Grip Royal, Circuit Performance

Bolt pattern: 6 x 74mm:
Nardi, Personal

Bolt pattern: 9 x 100mm:
Moto Lita, Lecarra, Springalex

Bolt pattern: 5 x 2.75″:
Victor 5 bolt, Grant 5 bolt

Well, I hope this article covers most of the frequently asked questions related to choosing and fitting an aftermarket steering wheel to a car. If not, feel free to get in touch.