What's the wideset rear tire that will fit on an '09 F?  Can I fab a new brake bar with an extra bend in it and buy enough clearance for a 150? 

Some 150 tires will just clear the brake bar and some will touch it.  A little bend added to the brake bar will provide clearance for any 150 tire on the stock 3.5" rim.  I ran a 150/70 Lasertec that just cleared the bar and then a 150/70 RoadAttack that touched it.  I pulled the brake bar and with it lying on a 2x4 with the rub mark up I beat it with a BFH right on that spot and it flatened just slightly and the ends bent upwards giving good clearance for any 150/70 tire.  I'm running a 150/70 Roadrider now.

OK.  Cool.  But, should I go with a 150 on a stock wheel?  Or is 140 the widest I should go on a stock wheel?  I don't wanna buy a Katana wheel.

I've got a 150 RoadRider on the stock wheel... and it barely clears the bar (and chain guard).  I bought off of GSJacks logs that have been posted - and also the RoadRider does have a 3.5" rim acceptable fit (via Avon tyres info).

Why would you change the tire? Anything other than a 130 will change the way the bike acts ( not in a good way ). You should also change the rims with wider ones if widening the tire is a must.

really i am running a 120/60-17 front and a 160/60-17 rear and it did change the way the bike acts very much so but your wrong about the in a bad way.  I love the gs in turns now Not a mod for the novice tho.  alot of  with a BFH

well, a 150 has a wider tread patch obviously.......and, a wider tire would look nice

Mounted a 150/70 Metzeler Z6 on the stock rims without any issues except bending the brake bar. 

Very cool! And i'm assuming the chain guard has to be removed or cut? 

No, chain guard will clear a 150 tire on the 3.5" wheel.

Quote from: Bridger on June 28, 2009, 12:42:20 PM
Very cool! And i'm assuming the chain guard has to be removed or cut? 

Actually I forgot to mention that. I did put a small notch in the chain guard with a dremel tool for added clearance around the tire.  But as GSJack says, it's probably not necessary. 

Thank you for the info kind sirs....I got 620 miles on my stock 130(BATTLAX), what's it worth if I was to sell it?

Not sure, but here's what Dennis Kirk has them for.  Get what you can and apply it to the new tire.  Good luck

http://www.denniskirk.com/jsp/product_catalog/Product.jsp;jsessionid=UXWZZ4NSKWYGBLA0WTKSM4VMDK0NCIV0?store=&skuId=543054

Edit: typo