need help on rear wheel

[fischer550]

So I am thinking about buying this rear wheel for my bike on ebay. http://www.ebay.com/itm/XLC-Rear-Wh...42?pt=US_Wheels_Wheelsets&hash=item4865b5b732

Would it be strange/look funny if I used a 26x1.75 rim in the back but a 26x1.5 in the front, and would I need 2 different sized tires?

Also, if I were to buy this wheel, what would I need to convert it to a single speed FREEWHEEL? A link would be super helpful, preferably ebay. Thanks!

 

[Davezilla]

I don't see why it wouldn't work... and to convert it to a single speed freewheel you'll just need a hub with teh same number of spokes to lace into the rim