Can I use a tire with a lower speed rating than the original?

It is not recommended. Use a speed rating at least as high as your owner's manual or the original tire specifies, even if you never ride that fast, because the rating also reflects how the tire is built.

Can I use a higher load index than stock?

Generally yes, as long as the size, construction and fitment are correct. A higher load index is not a problem by itself, but it does not let you overload the bike beyond its own weight limit.

What does a speed rating in brackets mean?

A rating like (W) in brackets means the tire is rated above 168 mph, with the actual maximum set by the tire maker. You usually see it on high-performance radials marked with ZR in the size.

Is the load index the weight in pounds?

No. It is a code you look up in a load table. For example, a load index of 58 corresponds to about 520 pounds per tire at the maker's specified pressure.

Motorcycle tire load index and speed rating explained

A motorcycle tire's load index and speed rating are the number and letter printed right after the size, such as 58W in 120/70ZR17 M/C 58W. The load index is a code you cross-reference in a load table to find the most weight the tire can carry at its specified pressure, and the speed rating letter shows the highest sustained speed the tire is built for. Your replacement tires should match or exceed the ratings listed in your owner's manual.

Here is how to read both, what the common values mean, and what happens if you pick the wrong ones.

Where to find the load index and speed rating

Look on the sidewall right after the tire size. Common formats:

120/70ZR17 M/C (58W) — load index 58, speed rating W, with brackets
180/55ZR17 M/C 73W — load index 73, speed rating W
130/90B16 M/C 73H — load index 73, speed rating H
MT90B16 72H — load index 72, speed rating H

On older or smaller tires, the load index and speed rating may be missing or shown in a different format. Check the tire maker's catalog if you cannot find them.

Motorcycle tire load index explained

The load index is a two- or three-digit number. On its own it is not a weight. You use it to look up the maximum load the tire can carry at its specified inflation pressure.

Motorcycle tires usually fall in the 40s to the 80s. Some common values:

Load index	Max load (kg)	Max load (lb)	Typical use
50	190	419	Small bikes, scooters
55	218	481	Lightweight front tires
58	236	520	Common sport front tire
62	265	584	Larger front tires
65	290	639	Heavy front, light rear
69	325	716	Mid-size rear tires
73	365	805	Common sport and cruiser rear
75	387	853	Large rear tires
78	425	937	Heavy touring rear

Each figure is per tire, at the maker's specified pressure. Running low pressure reduces how much load the tire can safely carry.

Why load index matters on a motorcycle

Two-up riding and luggage put much more weight on the rear tire.
Heavy cruisers and touring bikes need higher load ratings, which is why many use bias-belted tires with "reinforced" designs.
Underrated tires can overheat and fail under load, especially at highway speed.

Some heavy-duty tires are marked "Reinforced" or "RF". These carry more load and usually need a higher pressure to do it.

Motorcycle tire speed rating explained

The speed rating is a letter that tells you the maximum sustained speed the tire can handle when it is carrying its rated load and is correctly inflated.

Speed rating	Max speed (mph)	Max speed (km/h)
L	75	120
M	81	130
N	87	140
P	93	150
Q	99	160
R	106	170
S	112	180
T	118	190
H	130	210
V	149	240
W	168	270
Y	186	300
(W)	Over 168	Over 270

ZR and bracketed ratings

A Z inside the size, as in 190/50ZR17, is an older way of showing the tire is rated for speeds above 240 km/h (149 mph). It does not tell you the actual limit. Look at the letter after the load index for that.

A bracketed rating such as (W) means the tire is rated above 270 km/h (168 mph), and the tire maker sets the actual maximum.

Why speed rating matters even if you ride slowly

A speed rating is not just a top-speed number. A higher-rated tire is usually built with stiffer construction and compounds that handle heat. That affects:

Stability under hard braking and cornering
How the tire handles heat on long highway rides
Steering feel

Fitting a lower speed rating than stock can change how the bike handles and leaves less margin if the tire runs hot or underinflated.

How to choose the right ratings

Check your owner's manual or tire placard. It lists the minimum load index and speed rating for the bike.
Match or exceed both. A higher rating is generally fine. A lower rating is not recommended.
Think about how you load the bike. If you ride two-up or with heavy luggage, a higher load index can add margin. You still cannot exceed the bike's own maximum weight.
Keep the size correct. Ratings only help if the size and construction are right. Our guide on how to choose motorcycle tires covers the rest of the decision.
Use the right pressure. The load index assumes the specified pressure. See the manual and our guide to checking motorcycle tire pressure.

Load and speed rating mistakes to avoid

Mistake	Why it matters
Buying a lower speed rating to save money	Less heat tolerance, different handling
Using a car or trailer tire	Not built for a motorcycle's profile or loads
Ignoring "front" and "rear" markings	Front and rear tires are designed differently
Mixing radial and bias front and rear	Can cause unpredictable handling
Riding two-up on underinflated tires	Overloads the tire and builds heat
Assuming a new tire is fresh	Old stock tires age even unused

Age matters too. A tire with the right ratings can still be too old to trust. Learn how to check with our guide to motorcycle tire date codes.

How load and speed ratings interact with tire pressure

The load index assumes the tire is inflated to the pressure the tire maker specifies for that load. The speed rating assumes the same thing. Both ratings fall apart if the tire is underinflated.

An underinflated tire flexes more with every rotation. That flexing builds heat, and heat is what breaks down a tire's structure over time. Add a passenger, saddlebags and a hot highway, and a tire that is only a few psi low is working much harder than its ratings assume.

Practical habits:

Check pressure cold, before you ride, with a good gauge.
Use the loaded pressure in your manual when riding two-up or carrying luggage. Many bikes list a higher rear pressure for full loads.
Do not inflate to the sidewall maximum unless the manual says so. That number is a limit, not a target.
Recheck after big temperature swings, since pressure drops in cold weather.

Do aftermarket or replacement tires have to match exactly?

Not exactly, but they must meet the minimum. For example, if your manual specifies a 73V rear, a 73W is fine. A 70V or 73H is below spec and not recommended.

Also check:

Front and rear pairing: use tires designed to work together.
Construction: radial, bias or bias belted, as specified for your bike.
Tube type vs tubeless: must suit your rims.

Cost considerations

Costs vary by bike, region and shop. Higher speed ratings and heavy-duty touring tires often cost more. Labor for mounting and balancing is usually separate. Our motorcycle tire replacement cost guide gives typical ranges.

When to see a mechanic

See a tire professional if:

You cannot find the correct load index or speed rating for your bike
Your current tires are below the manual's ratings
You carry heavy loads or a passenger and want advice on tire choice
A tire shows bulges, cracking, cuts or exposed cords
The bike feels unstable, weaves or wobbles at speed

A motorcycle tire shop can confirm the right tire for your bike and how you ride.