Yes. The letter is speed, the number is load
This covers safety envelope, not rate of wear


Image from Avon Tyres

 

How do I know which L.I. is needed for my Sportster, from the gross axle weight rating?

 

Note: The D404 is not meant to be used on Harley-Davidson motorcycles due to the tires' lower load capacity ratings. Please see the Dunlop Harley-Davidson D402/401 series tires for increased load capacity.

From what I remember you need a 72H front and at least a 74H rear.

The "H" speed rating is over rated, IMHO... A 833 Sporster can do 130 MPH, only IF flying off a cliff.

Same as a Burgman 650, H is over rated

 

The tyre the vehicle manufacturer recommends may seem very over specced but there are reasons for this.
(skip the rest of this if you are easily bored)

There is a huge rabbit hole here about the difference between industry and consumer level use of these numbers - I’m going to try to skim the surface

There are standardised methods to get to the tyre manufacturer‘s maximums.
The bike manufacturer has further considerations.

For example motorcycle tyres are critical suspension components and by changing the spec above minimums you can firm up the suspension contribution from the tyre.
This is particularly significant to bike handling because bikes lean out of vertical causing the suspension to be out of vertical. So a vertical bump acts out of plane with the suspension and your tyre has to take on more responsibility for dealing with it.

So you can use the ratings as minimums for the bikes attributes and that is fine but there is more to it the deeper you go.

 

✔ to the above.

From the 2007 Owners' Manual:
ALL Sportsters-
Gross weight 1,000 lbs.
Front gross 335 lbs.
Rear gross 665 lbs.

 

My state's DOL says my Burgman 650 has a GVW of 1,800 pounds and I pay $25 in weight fees.

 

you need to switch to lite beer in the trunk !

 

Is that a class weight Dave? (ie. up to...)
650 handbook gross weight of 999 lbs

 

I have tried to get an answer. The major city that controls our county is Seattle so 80% of out rural taxes go there. I am not in a city, it's unincorporated county.