replacement hub guard

So this hub guard is something you want to add yourself?
Has to be, since it's not part of Shimano tech docs for that hub:techdocs.shimano.comEV FH 2200 2202B v1 m56577569830727947.pdfOpen ↗

Which would indicate that the hub is expected to do just as well without it.

Why do you think you need it?

The one you linked to is very unlikely to fit your hub, and - unless you plan on doing grinds - won't be of any use to you or your bike.

But since it's not part of the seal/dust shield/dust cap, you don't need to worry about the gap either, if you still want to use it.

Good response. I've only had one bicycle, so I've never had a bicycle without one, so I assumed it was important.

Since it might protect the nuts from rain, I'm still going to shorten the old one until it fits between the hanger.

Thanks

Quoted post said:

Originally Posted by urge2kill
Good response. I've only had one bicycle, so I've never had a bicycle without one, so I assumed it was important.

Since it might protect the nuts from rain, I'm still going to shorten the old one until it fits between the hanger.

While your concern for the rear hub's exposure to the elements is not unwarranted, I think that dabac poses a valid question ["Why do you think you need it?"] which you may want to think about a little longer before taking the time to fit the rubber boot to your bike's rear wheel ...

FYI. The "rounded" metal cover IS the cover to shroud the bearings from dust, dirt, water, etc. ...

And, no additional cover is needed.

Not all hubs have rubber boots ...

Not all MTB rear hubs have rubber boots ...

• early Shimano MTB hubs did not have a rubber boot
  
• even second generation XTR hubs (950 series) did not have a rubber boot
  

UNLESS you are planning on replacing the "rounded" cover + cone on the hub you pictured with the "labyrinth" cone-assembly + boot which Shimano uses on many of their MTB hubs then what may be a better option is REGULAR, post-ride maintenance whereby you wipe the bike off [rinse with clear water, as necessary] & simply apply a light layer of grease to the nuts on the end of the axle.

I already made it fit. It didn't take much.

Quote: what may be a better option is REGULAR, post-ride maintenance

These aren't mutually exclusive.

I will check on how it's working once my bicycle gets wet.