new players out there. If you got a loadout card with the cricket bat DON’T run with it in your hands it’s faster to run with a pistol.
Don't run with the cricket bat
Looking at the stats on the wiki, machine pistols have 90% or 95% move speed. Handguns, the cricket bat, the kukri, and the katana have 97.5% move speed, and the two basic knives have 100% movespeed.
If you have a handgun and a cricket bat/other advanced melee weapon, it doesn’t matter which one you run with. If you have a machine pistol as your secondary, it is always better to have your melee weapon equipped, no matter which one you have. In general, your melee weapon will always be at least as fast as your secondary.
It is worth noting that running with abilities out (stickies/medpacks/etc) might be faster than a cricket bat/pistol. Unfortunately, I don’t have solid numbers here, but some abilities might give 100% move speed. However, REVIVR/minigun/grenade launcher definitely do slow down your run speed (see the wiki link).
Actually, the pistols AND heavy melee weapons (cricket bat, Katana and kukri) all have 97.5% run speed. The only weapons that are faster than this is the Beckhill knife and Stilnotto Stiletto. Like Retief said, if you have a machine pistol as a secondary though, it will be slower than the melee weapons.
Melee weapons will ALWAYS be the fastest, or equivalent to the fastest, hand-held item. The only reason you might choose to hold your secondary instead of a cricket bat, is because you can see more on the screen. 
And being able to shoot on short notice?[/quote]
Many players like to have their weapons close or on hand when their mobile at the cost of their sprint speed. Regardless of how it hinders your mobility, It acts as an equalizer if you find yourself coincidentally colliding with an enemy player who just so happens to be around the corner. Make no mistake! Confronting enemies with your secondary weapon isn’t always the greatest idea, but It’s better than finding yourself welding your trusty cricket bat (even if you love it that much) against a startled Bushwanker with a turret at the ready. If you have the time during a firefight, quickly switch to your Primary weapon.
And being able to shoot on short notice?[/quote]
Many players like to have their weapons close or on hand when their mobile at the cost of their sprint speed. Regardless of how it hinders your mobility, It acts as an equalizer if you find yourself coincidentally colliding with an enemy player who just so happens to be around the corner. Make no mistake! Confronting enemies with your secondary weapon isn’t always the greatest idea, but It’s better than finding yourself welding your trusty cricket bat (even if you love it that much) against a startled Bushwanker with a turret at the ready. If you have the time during a firefight, quickly switch to your Primary weapon.[/quote]
unless opponent is low hp you are almost always better off switching to main weapon.
What about the running speed with Small Equipment?
Like Vassili Heartbeat Sensor and Fletcher Detonator?
Can you run at 100% speed with it?
In some circumstances, you are able to run fastest with abilities out, like the heartbeat sensors, healing pulse, and sometimes med packs. Other abilities can also make you slower than you would with a primary.
I’ve often wondered that as well. As Vass I usually run holding my heartbeat sensor, though I’m not sure whether this affects my overall speed as a whole, compared with running with a melee weapon.