How to Correctly Change a Tyre & Inner Tube on Vespa & Lambretta Split Rims

Changing a tyre and inner tube is one of those jobs that every classic scooter owner will eventually need to tackle.

Whether you're restoring a Vespa PX, Rally, Sprint, Super or any other classic Vespa, or working on a Lambretta, many of these scooters use split wheel rims.

Unlike a modern tubeless wheel rims from SIP, A.F. and BGM, a split rim comes apart into two halves, allowing the tyre and inner tube to be removed much more easily.

However, there is a right way and a wrong way to do the job.

We'll explain how to safely remove the old tyre and inner tube, inspect the split rim, fit the new tube and tyre, and correctly reassemble the wheel.

Important Safety Warning

Before doing anything else:

The tyre must be completely deflated before separating a split rim.

Never attempt to undo the split-rim nuts while the tyre is inflated.

Separating an inflated split rim can allow the rim halves to separate violently and cause serious injury.

Always:

1. Remove the valve cap.
2. Remove the valve core.
3. Allow the tyre to completely deflate.
4. Confirm that there is no remaining air pressure.
5. Only then remove the split-rim nuts.

This is one of the most important rules when working with classic scooter split rims. Y

What You'll Need

Before starting, gather everything you need.

You will normally require:

• Correct replacement tyre
• Correct inner tube (if fittingto a lambretta there are two different tubes you can buy. 45 or 90 valved inner tubes)
• Suitable spanners or socket set (13 or 14mm depending)
• Suitable pump
• Tyre bead lubricant (washing up liquid)
• Wire brush
• Cleaning materials
• Torque wrench
• New split-rim nuts and washers where required (we prefer zinc plated nuts and washers)

You may also want:

 

• New rim halves if the originals are badly corroded

Workshop Tip

If you're fitting a new tyre, it's usually sensible to fit a new inner tube at the same time.

An old tube may have been stretched, hardened or damaged during previous tyre changes.

A new tyre deserves a new tube.

Step 1 – Remove the Wheel

Remove the wheel from the scooter.

Make sure the scooter is properly supported before removing the wheel.

Never rely solely on the stand while carrying out work that could make the scooter unstable. A 2 man job is better than 1.

Step 2 – Remove the Valve Core

Before separating the rim, remove the valve core if possible.

This allows the remaining air inside the tube to escape.

Listen for the escaping air and allow plenty of time for the tyre to completely deflate.

Once you think the tyre is flat, press the tyre sidewall in several places to make sure there is no remaining pressure. This is becoming more and more difficult as tyres such as Michelin S1 & S83 are designed for tubeless wheel rims as standard. This naturally gives them a tighter fit the the wheel rim.

 

Step 3 – Remove the Split-Rim Nuts

Once you're certain that the tyre is completely deflated, remove the nuts securing the two rim halves together.

Keep the nuts, washers and other hardware together if you intend to reuse them although we recommend new fixings.

However, if the fasteners are rusty, damaged or questionable, replace them.

Important

Undo the nuts evenly rather than removing one completely while leaving the others tightly loaded.

Once the nuts are removed, carefully separate the two rim halves. 

Step 4 – Separate the Rim Halves

With the nuts removed, the two halves of the rim can be separated.

Sometimes they will come apart easily, most of the time, this can be the most difficult part as they can be difficult to remove. 

Most of the time, especially on an older scooter, they may be stuck together because of:

• Rust
• Dirt
• Old paint
• Corrosion
• Powder coating
• Old tyre debris

Don't start attacking the rim with a hammer.

Carefully work the halves apart while avoiding damage to the sealing surfaces and rim and try not to give yourself a hernia.

Step 5 – Remove the Tyre and Inner Tube

Once the rim is separated, remove the tyre from the rim.

Take out the old inner tube.

If the tube has failed, sling it straight in the bin.

The location and appearance of the damage can sometimes tell you what caused the problem.

For example:

Hole on the inner side of the tube

Could indicate:

• Rim damage
• Sharp edge
• Corrosion

Hole on the outer side

Could indicate:

• Puncture
• Nail
• Screw
• Other object penetrating the tyre

Two small holes close together

This can sometimes indicate a pinch flat, which can happen if the tube has been trapped between the tyre and rim during fitting.

Step 6 – Inspect the Rim

This is an extremely important step.

Don't simply remove the old tyre and immediately fit the new one.

Inspect both rim halves carefully.

Look for:

• Rust
• Corrosion
• Cracks
• Sharp edges
• Damaged threads
• Bent rim sections
• Damaged valve-hole area
• Excessive paint
• Powder coating
• Previous repairs
• any stud damage on both the wheel rim and the hub

Run your fingers carefully around the inside of the rim.

You are looking for anything that could damage the new inner tube.

Workshop Tip

If the rim has heavy corrosion, don't simply clean it enough to make it look good.

Ask yourself whether the rim is actually safe to reuse.

A split rim is a structural component of the wheel, so damaged or badly corroded rims should be replaced.

Step 7 – Check the New Tyre

Before fitting the new tyre, check it carefully.

Look at:

• Tyre size
• Load rating
• Speed rating
• Direction of rotation
• Manufacturer markings
• Production date
• Overall condition

If the tyre has a directional arrow, make sure it will rotate in the correct direction when the wheel is fitted to the scooter. Sometime the front tyre with have a different rotation to the rear on the same tyre.

Important

A tyre can physically fit a rim while still being the wrong specification for the scooter.

Always use the correct tyre size and specification.

Step 8 – Check the Inner Tube

Make sure the inner tube is the correct size and valve angle for the tyre. Lambretta riders tend to stick a 45 degree tube in the front to clear any distance between the valve and the fork link bolt.

For example, don't assume that because the tyre says one size, any tube that looks approximately the same will work.

The tube should be designed for the tyre size and valve arrangement.

Check the valve stem before installation.

Make sure it isn't damaged and that it sits correctly in the rim.

Step 9 – Fit the Inner Tube Into the Tyre

Before fitting the tube, put a small amount of air into it.

You don't want it fully inflated.

You simply want enough air to give the tube its shape.

This helps prevent the tube from becoming twisted inside the tyre or pinching between rims.

Place the tube inside the tyre and make sure it sits evenly all the way around.

Workshop Tip

A small amount of air in the tube makes a big difference.

A completely flat tube can fold over itself and become trapped when the tyre is fitted.

Step 10 – Fit the Tyre Onto the First Rim Half

Run some washing up liquid around the wheel rim.

Position the tyre onto one half of the split rim.

Pay attention to the valve position.

The valve stem needs to pass correctly through the valve hole.

Work the tyre bead over the rim carefully if possible. If not, inflate the inner tube to push the trye on the rim.

 

Don't Force It

If the tyre is extremely difficult to fit, don't simply apply more force.

Check that:

• The tube isn't trapped
• The bead is sitting correctly
• The tyre is the correct size
• The rim is the correct size
• The opposite side of the tyre bead is sitting down in the centre of the rim

Getting the bead into the rim's centre well gives you more slack and makes fitting much easier.

Step 11 – Fit the Second Rim Half

With the tyre and tube positioned correctly, install the second half of the split rim.

Carefully bring the two rim halves together.

Make sure:

• The tube isn't trapped between the rim halves
• The tyre bead is sitting correctly
• The valve is correctly positioned
• The rim halves are properly aligned

This is one of the most important parts of the job.

Step 12 – Install the Split-Rim Nuts

Fit the washers and nuts.

Start all of the nuts by hand.

Don't fully tighten one nut while the others are still loose.

Instead, tighten the nuts gradually and evenly in a criss-cross pattern.

This allows the two rim halves to come together evenly.

Important

Use the correct fasteners for your particular wheel.

If the manufacturer specifies a torque setting, use a torque wrench and follow that specification.

Don't guess at critical wheel fastener torque as you will probably snap a rim stud

Step 13 – Check the Inner Tube

Before inflating the tyre fully, check around the entire circumference of the tyre.

Make sure:

• Tube isn't trapped
• Rim halves are correctly seated
• Valve is straight
• Tyre bead is positioned correctly
• No part of the tube is visible outside the tyre

If anything looks wrong, stop and correct it before inflating.

Step 14 – Inflate the Tyre Carefully

Inflate the tyre gradually.

Don't immediately inflate it to a high pressure.

Watch the tyre as it inflates.

The bead should seat evenly around the rim.

Look around both sides of the tyre and make sure the moulded line around the tyre is an even distance from the rim.

If one section is sitting noticeably deeper or higher than another, stop.

Deflate the tyre and investigate.

Workshop Tip

A suitable tyre lubricant can help the bead seat correctly.

Avoid using petroleum-based products that could damage rubber.

Step 15 – Check the Tyre Bead

Once the tyre has inflated, carefully inspect both sides.

The bead should be seated evenly around the entire circumference.

Look for:

• Uneven bead position
• Bulges
• Pinched areas
• Tube showing
• Tyre distortion

If you're not happy with the seating, deflate the tyre before attempting to correct it.

Don't try to force a badly seated bead into position while the tyre is highly inflated.

Step 16 – Set the Correct Tyre Pressure

Once everything looks correct, set the tyre pressure recommended for your particular scooter, tyre and riding conditions.

Don't simply copy the pressure from another scooter.

Tyre pressure can depend on:

• Scooter model
• Tyre specification
• Rider weight
• Passenger/load
• Tyre manufacturer

Always follow the tyre manufacturer's recommendations and the scooter manufacturer's guidance where available.

Step 17 – Refit the Wheel

Once the tyre has been correctly fitted and inflated, refit the wheel to the scooter.

Make sure the wheel is correctly seated on the hub/brake drum.

Install the correct wheel fasteners.

Tighten them evenly and use the correct torque specification for your model.

Step 18 – Final Checks

Before riding the scooter, carry out a final inspection.

Check:

Wheel fasteners

Are they correctly tightened? we also recommend double checking all fixings after your first outing. 

Split-rim fasteners

Are all nuts correctly tightened?

Tyre pressure

Is it correct?

Valve

Is the valve sitting correctly?

Tyre

Is the bead evenly seated?

Wheel

Does it rotate freely?

Brake

Does the brake operate correctly?

Tyre clearance

Does the tyre clear the frame, engine, suspension and other components?

Common Mistakes When Changing Split-Rim Tyres

Mistake 1 – Separating an Inflated Rim

Never do this.

Always completely deflate the tyre and remove the valve core before separating the rim.

Mistake 2 – Reusing an Old Inner Tube

Old tubes can become brittle and stretched.

A new tyre is a good time to fit a new tube.

Mistake 3 – Ignoring Rim Corrosion

Rust inside a split rim can damage the tube.

Severe corrosion can also compromise the rim itself.

Inspect the rim properly before reuse.

Mistake 4 – Pinching the Inner Tube

This is particularly common when fitting the tyre.

Keep the tube correctly positioned inside the tyre. You use something flat and blunt to push away the inner tube between the rims just before you tighten the nuts. 

Mistake 5 – Tightening One Rim Nut Fully First

The rim halves need to come together evenly.

Start all the nuts and tighten them progressively in a criss-cross pattern.

Mistake 6 – Using the Wrong Tube

The tube must match the tyre size and valve arrangement more importantly.

Mistake 7 – Ignoring the Direction of Rotation

If the tyre is directional, make sure the rotation arrow points in the correct direction.

Vespa Split Rims vs Lambretta Split Rims

The basic principle is the same on both scooters:

Deflate → separate rim → remove tyre/tube → inspect → fit tube → fit tyre → reassemble → inflate → check.

However, the exact wheel, rim, hub and fastener arrangement can vary between Vespa and Lambretta models.

You should therefore always check the correct parts and specifications for the scooter you're working on.

This is especially important if the scooter has been modified or fitted with aftermarket wheels, hubs or tyres.

Which Vespa Models Use Split Rims?

Many classic large-frame Vespa models use split rims, including models such as:

• Vespa Rally
• Vespa GS
• Vespa SS
• Vespa Small Frame
• Vespa Sprint
• Vespa Super
• Vespa GT
• Vespa GTR
• Vespa PX
• Vespa PE
• Vespa T5

There are differences between individual models and years, so always check the wheel and rim fitted to your particular scooter. Both hub and wheel rim studs should take a 13mm open nut with both a split and flat washer.

Which Lambretta Models Use Split Rims?

Split-rim wheels are commonly found on classic Lambrettas including:

• LI
• LI Special
• TV
• SX
• DL
• GP

Again, specifications can vary, particularly on restored or modified scooters. Nut and washer variation is 13 or 14mm domed nuts with nyloc Insert to cover the hub studs, 13 or 14mm open nuts for wheel rim studs. Both nuts used a wavy washer under them

When Should You Replace a Tyre?

Don't wait until a tyre is completely worn out.

Replace it if you find:

• Cracks
• Perishing
• Bulges
• Cuts
• Damaged sidewalls
• Excessive wear
• Exposed canvas
• Uneven wear
• Signs of age-related deterioration

Classic scooters often don't cover huge mileages, which means a tyre can look unworn while still being very old.

Age matters as well as tread depth.

When Should You Replace a Rim?

A split rim should be replaced if it has significant:

• Corrosion
• Cracks
• Bends
• Damaged threads
• Distortion
• Structural damage

Don't take chances with wheels.

If you're unsure whether a rim is safe to use, have it inspected by someone experienced with classic scooters.

A Useful Workshop Checklist

Before you start:

☐ Correct tyre
☐ Correct inner tube
☐ Tyre levers
☐ Valve-core remover
☐ Correct tools
☐ Tyre lubricant
☐ Clean work area

During assembly:

☐ Tyre completely deflated
☐ Rim inspected
☐ Rim tape checked
☐ Tube correctly positioned
☐ Valve correctly located
☐ Rim halves aligned
☐ Nuts tightened evenly

Before riding:

☐ Tyre bead seated
☐ Correct tyre pressure
☐ Wheel fasteners tightened
☐ Split-rim nuts checked
☐ Wheel rotates correctly
☐ Brake operates correctly
☐ Tyre clears all components

Final Thoughts

Changing a tyre and inner tube on a classic Vespa or Lambretta isn't particularly difficult once you understand how the split rim works.

The most important part is taking your time and doing the job safely.

Remember the golden rule:

Never separate an inflated split rim.

Completely deflate the tyre, inspect the rim carefully, use the correct inner tube, take care not to pinch the tube and tighten the rim fasteners evenly.

If you do that, changing a tyre becomes a straightforward part of maintaining your classic scooter.