Fatboy wheels on stock xs swing arm. Need help, I'm stupid!!

teionjames

teionjames

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I'm in the process of my first build and jumped the gun and got a set of fatboy wheels dirt cheap. I've always liked the look of the fatboy wheel, has a "mad max" kind of vibe to it. My problem is is that I'm doing a brat style build with the stock swing arm. I'm unsure as to whether or not the fatboy wheel will fit, or what I'll have to do in order to make it work. I want to run a 5 inch rear tire so that causes even more trouble in the spare room department. Any info or advice would be beyond appreciated. Even if it's to tell me it's impossible, I'd rather hear that from some guys who know what they're talking about. Thanks.
 
It's impossible with stock swing arm, max tire size is 120 or 130 depending on the tire and arm you've got. If you put a wider swing arm on that only gets you to 140 then you hit the chain. Need to move the sprockets and chain out and the only set available for xs650 costs crazy money.

Edit: I had to look up what a 5" tire is in metric, I thought we were talking about a really fat tire. If a 5" tire is equal to a 130 you might get it in the stock arm.
 
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GreasyC I was literally about to type "I thought a 130 was a 5 inch tire" haha.....My biggest fear is that the wheel is too wide at the "hub" once the sprocket and rotor are on. I did some crude very fast measurements when I was tearing her down the other day and should have room for the tire, just not sure about the stop and go parts. Won't get back in the shop until Monday so fingers crossed! Thanks for the info, much appreciated.
 
Also, keep in mind I'm new to the xs world, I've heard that a drum brake swing arm and a disc brake swing arm are different sizes? I think they meant in length but again I'm not sure, as far as I know that could be completely wrong.
 
Finally got to mock up the rear wheel. I was worried about nothing, there's more than enough room back there.
IMG_0146.jpg
 
A friend just adapted a set on a Road Star, and had quite a time with the finer points of it. He used my axle adapters for Road Stars on the front, but the rear took some work to get stacked right. You are going to want some serious shocks and forks with that kind of unsprung weight on that light of a frame to keep it from wearing ya out.
Hope it goes well.
 
1 of my Xs's has a 150 tire on it with stock swingarm ,has about 3/16 of clearance
 
The only difference between the disc brake a drum brake swing arm is the mounting point for the brake. The drum is on the bottom, the disc on top. There might be s light difference near the brake pivot shaft. It may be flattened a bit for clearance.
On tires the brand and model of the tire can make a difference. I had a 140 on my 75 and it scrubbed on both sides. A bit of grinding on the edges of the tire and it ran ok.
Leo
 
So I got new 3/4 Harley bearings for the fatboy wheels and they still won't fit with my stock xs axle!! So I have a local machine shop making a custom axle that will work. Never thought this would be that much trouble!! Next time I'll stick with yamaha wheels
 
Of course that won't work. 3/4 inch is 19.05 mm. The XS axle is almost 1 mm to big.
Leo
 

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