If you have a 21×3.5 rim and are trying to figure out what tire size would be the best fit? Here we got you covered. Motorcycle wheel sizes can be confusing for new riders.

With so many different wheel sizes available, it’s hard for a new rider to know what kind of tires do I need for my motorbike?

This blog will answer all your queries! We have broken down the most common wheel sizes for 21’’ rim to help you make an informed decision about which tire size is right for your needs!

How To Read Motorcycle Tire Size?

There are 5 main determinants of motorcycle tire size that need to be considered when identifying the right tire size. These are:

•           Width

•           Aspect Ratio

•           Tire Construction

•           Speed Rating

•           Rim Diameter


The larger the width, the wider the tire! Usually, the width of the tires ranges between 100mm to 300mm.

Aspect Ratio

The height of the tire profile is the aspect ratio. It means the taller the tire, the heavier they are!

Tire Construction

Two basic tire types are – Radial and Bias Ply.

Radial tires cost more to replace; however, they are more durable and offer excellent puncture resistance. Bias Ply offers soft long-distance rides!

Speed Rating

The maximum speed of a tire is defined by the speed rating, designed differently for each tire type.

Rim Diameter

The wheel’s rim diameter is used to mount the tire in inches.

What tire type do you need? Tires are of both types – Tube or Tubeless!

Tubeless Tires are the latest tire design for a motorcycle. If your bike has cast wheels, tubeless tires are the best choice!

These tires offer higher durability against punctures and deliver improved braking power. Tube Tires should be installed if your Harley has spoke wheels.


Tire Size         Rim (inch)

80/90-21          1.60 – 2.15

90/90-21          1.85 – 2.50

120/70-21        3.00 – 3.75

130/60-21        3.00 – 4.00

140/70-21        3.00 – 3.75

What size does a tire fit a 3.5 rim?

150 Max is the ideal tire for a 3.5 rim. However, if you want a wider 160 or 170, the deuce rear (4.5) will be used to bolt up to your tire.

What size tire will fit the rim?

You can look for a driver’s door jam, the sticker with the tire information, or the owner’s manual to check what size tire is right for your bike’s rim.

Will a 21 wheel fit a Street Glide?

Yes, a 21-wheel size can fit in a Street Glide.


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