5.5" Rim on '10 FE570

A question for you super motard riders....

I just got a 2010 Husaberg Fe570 and want to put SM wheels on it. I found a set of wheels and tires from an 05 KTM SMR 525. They are made by behr for KTM. They should bolt right up from what I've read.

However the rear is a 5.5" wide rim - which means I probably would have to run a pretty wide tire (a 165 is mounted now)

The front is 3.5" wide and is a 120.

A stock FS570 runs a 4.25" rim, and others that change over to SM run a 5". Should I be concerned with such a wide rim on the back? Apparently it will bolt right up no problem but I am wondering if I will regret buying it later.

I might be able to get the entire set for $500 with a set of rain tires all mounted.

They aren't cush hubs either.

Hey Scott, good to know! I passed on that deal. Should I be looking at 4.25" or rear rims? Also what sized tire - 150 or 160? I am thinking about a set of warp 9 wheels but I don't think they come with a cush hub. How important is that?

So far I found I can get a cush hub from the following:

Excel Talon
Rad Mfg
HAAN Wheels

I can get Excel rims on Rad Mfg Cush hubs (2 wheels) for $1,270 USD. That's the best option so far.

In the following configuration:

17x4.25 RR
17x3.5 FF

Are we allowed to post links?

Why is 4.25" a no-go? I am ready to pull the trigger on brand new wheels from Husaberg.