Customer Question: I Have A Nardi Steering Wheel, Can I Use A MOMO Boss Kit?
Steering wheel fitting guide
We get this question a lot. Someone has a Nardi wheel, often a wood-rim classic, and the only boss kit listed for their car is a MOMO one. Can the two go together?
Yes, but not straight out of the box. Nardi and MOMO use different six-bolt patterns, so you need a part in between that is drilled for both. This guide explains the difference, the parts that bridge it, and what to check before you order.
- Nardi and Personal wheels use a 6 x 74mm bolt pattern
- MOMO, Sparco and OMP wheels and bosses use 6 x 70mm
- The two patterns do not line up, so a Nardi wheel will not bolt straight to a MOMO boss
- A dual-drilled B-G Racing spacer bridges the two
- On the B-G 6-bolt spacers, the 10mm and 20mm sizes do not convert between patterns
- A centre horn button may need a low profile retaining ring
What is on this page
Nardi wheels and why people keep them
Nardi is an Italian steering wheel maker founded by Enrico Nardi, best known for wood-rim wheels on classic Italian sports cars. The Nardi Classic and the Nardi Torino are the ones we see most. A lot of owners have had theirs for years and want to move it to a new car, or have bought a car that already came with one.
Any aftermarket wheel needs a boss kit, the car-specific hub that bolts to the steering column and gives the wheel something to bolt to. The boss kit range for older and less common cars is often MOMO, so the question of fitting a Nardi wheel to a MOMO boss comes up all the time.
Why they do not bolt straight together
Both brands use six bolts, but on a different pitch circle diameter (PCD), the circle the bolt holes sit on. Nardi and Personal wheels use 6 x 74mm. MOMO, Sparco and OMP wheels and boss kits use 6 x 70mm. The Nardi pattern also sits at a different angle, with two bolts at the top where the MOMO pattern has one.
That 4mm difference is small enough to look like it might work, but the holes will not line up. Never slot or open out the holes on a wheel or a boss to force a fit. The wheel is a safety part and the bolts need to seat properly.
| Bolt pattern | Brands |
|---|---|
| 6 x 70mm | MOMO, Sparco, OMP, Motacorsa, Reverie |
| 6 x 74mm | Nardi, Personal |
The parts that bridge the two
The simplest answer is a B-G Racing alloy steering wheel spacer. They are drilled for both 6 x 70mm and 6 x 74mm, so one side bolts to the MOMO boss and the other takes the Nardi wheel. They come in lengths from 10mm to 120mm, with bolts and a wrench in the set.
The catch is length. B-G say the 10mm and 20mm spacers need the same pattern on the boss and the wheel, so they do not convert. For a Nardi wheel on a MOMO boss, choose 40mm or longer.
A spacer also moves the wheel towards you, so think about seating position before you pick a length. If you only need the conversion, 40mm is the shortest that does it. If you want the wheel closer anyway, a longer spacer does both jobs, and the B-G adjustable spacer is drilled for both patterns too.
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Keeping a centre horn button
The retaining ring that holds a horn button into the back of the wheel can be wider than the spacer body. When it is, the ring fouls the spacer and the wheel will not sit flat. It happens most often on Nardi and Personal wheels.
B-G make a low profile retaining ring for this, part BG8361, drilled for both 6 x 70mm and 6 x 74mm. B-G list it for MOMO horn buttons. If you run a Nardi horn button, Garreth’s advice is to measure the ring on the back of your wheel and send us a photo before you order, so we can confirm the combination.
If you would rather avoid an adaptor
If you like the classic look but are buying a new wheel, a 6 x 70mm wheel bolts straight onto a MOMO boss with nothing in between. MOMO’s Heritage range, such as the Mod 07 Heritage wood wheel and the Indy Heritage, gives a period look on the MOMO pattern. Our guide to MOMO, Sparco and OMP compatibility covers which wheels and bosses share a pattern, and our steering wheel fitting guide covers the rest of the job.
If your car has a steering wheel airbag, fitting an aftermarket boss kit and wheel means losing it, so talk to us first if that applies to you.
Can I fit a Nardi steering wheel to a MOMO boss kit?
Yes, with a spacer or adaptor drilled for both 6 x 74mm and 6 x 70mm, because the bolt patterns do not line up on their own.
What bolt pattern does a Nardi steering wheel use?
Nardi and Personal wheels use a 6 x 74mm pitch circle diameter.
What bolt pattern does a MOMO boss kit use?
MOMO boss kits and wheels use 6 x 70mm, the same as Sparco and OMP.
Which B-G Racing spacer converts between the two patterns?
The B-G alloy 6-bolt spacers in 40mm and longer convert; the 10mm and 20mm versions need matching patterns.
Will my horn button still fit with a spacer?
Sometimes the retaining ring fouls the spacer, and B-G’s low profile ring BG8361 is made for that; send us a photo to confirm.
Drilled for both patterns, it lets a Nardi wheel sit on a MOMO boss without modifying either part.
Tell us your car and send a photo of the wheel's mounting holes, and we will match the boss kit and spacer for you.
