What bikes have a cassette in back?

[sed6]

I'm trying to upgrade the freewheel on my lectric XP, and find it extremely frustrating and limiting that it has a freewheel, which of course limits my gear selections. So my question is do any manufacturers including cassette on the rear, for easy upgrades? Ultimately I'm looking for an 11-42 spacing for my 'Lectric XP.

 

[Sierratim]

For a freewheel you're pretty much limited to 34t for your biggest cog (Shimano Megarange). Short pf changing your hub motor, you might consider also changing your chain ring to get the gearing you want. This GEAR CALCULATOR can model the impact of changes in gearing.