Rolling bag with shoulder strap ?

Rick Steves has a new rolling back pack! Look at it in his travel store on this website.

I usually use a rolling bag with a shoulder strap as my suitcase. My bag is a Delsey but is quite a few years old so they have likely changed the style. I suggest when looking at luggage you look at luggage intended for business travel carryon that will hold a lap top, etc. I just pack my clothes in it instead! I believe the dimensions of mine are about 9x14x16 inches, but I'd have to double check to be sure, well under the carry on rules. I love it because it is nothing to swing over my shoulder or cross body if I want my hands free. Most of the time I roll it as you indicate is your plan, and my 'personal item' slips over the handle. This Delsey usually weighs 17 pounds when it's packed. Have fun hunting!

Thanks Gemma, Rick Steves bags only come with a shoulder strap for the backpack style, which to me is redundant. The Delsey bag that comes with a shoulder strap is not a full size carry one. Although the Delsey bags do look nice. Any other ideas ?
Thanks

Hate to misread the question, but the new RS roller comes with a shoulder strap. Two in fact. They don't detach, but they do hide away. Most bags also come with handles for stairs etc. Not sure I've seen any with a detachable strap.

Opps, once again I was not clear enough. I ws not refering to the backpack style straps. ITs the single over the shoulder straps like this one http://travelstore.ricksteves.com/catalog/index.cfm?fuseaction=product&theParentId=126&id=35 which only comes on the RS backpack/suitcase version.
I was hoping there was someother brand that also had something like this but with wheels. I imaging that all I need are the attachment points and I could use any strap.

You may have a difficult time finding a roller bag with a single shoulder strap as the bags are often too heavy for one strap. Hope you find what you're looking for!