Milwaukee-Eight Softail frame width

[HarleySwede]

Hello, I am new here and hope to receive some input on a new project. First Harley for me! 
The new softail frame, released in 2018, comes in a wide and a narrow version. 
-Is it just the swing arm that is wider or also the base frame and the width of the pivot bearings?
-if so, what is the width difference of the two versions?
I am asking because I am about to purchase a bike for my custom project, that will receive a wide tire conversion. 

[rigidthumper]

Ronnies shows the various part numbers for the different frames, but no mention of dimensions.
LINK

[HarleySwede]

Thanks! It may be the rake angle that makes the part numbers different. 
The link to Ronnie's was useful anyway. 

[JSD]

What bike are you looking to buy? As a break out has the big arse . 

[HarleySwede]

I wanted to use the street bob as base for my project, just because the price is much lower than the breakout. I will replace the wheels, swing arm etc anyway. 
But I found information now that the chassis actually is wider, not just the swing arm. 

[Buglet]

  What part of the frame is supposed to be wider. I have a new ST sitting here that I might be able to get some measurements of off.

[Deye76]

"But I found information now that the chassis actually is wider, not just the swing arm."

Care to share that info? Thanks

[biggzed]

Street Bob and Breakout have different rake and trail. Street Bob 30 degree rake with trail at 6.0". Breakout has 34 degree rake with trail of 5.7". Tree part numbers are different, so it's safe to assume at least some of the differences are tied to trees. Could be some in the neck as well making the frame a different part number.

Swingarm is also different, but it's tough to tell if the Breakout swingarm will fit in the Street Bob frame. Fender struts bolt on, so that part is easy. What I cannot find online is the frame dimension where the swingarm mounts. On my 2021 Street Bob the inner frame dimension at the swing arm pivot shaft is appx 9". Tough to get an exact number, but it's close.

Maybe someone with a Breakout can give you a similar measurement. If they are different, I suspect it is going to be materially different.

Zach

[JSD]

Also pipes are not interchangeable. 

[speedzter]

Why not go into your local HD shop with a tape measure 😁

[HarleySwede]

"But I found information now that the chassis actually is wider, not just the swing arm."

Care to share that info? Thanks

From 4:50 is about frame differences:
https://m.youtube.com/watch?v=hMrUknd1RrA

[HarleySwede]

Street Bob and Breakout have different rake and trail. Street Bob 30 degree rake with trail at 6.0". Breakout has 34 degree rake with trail of 5.7". Tree part numbers are different, so it's safe to assume at least some of the differences are tied to trees. Could be some in the neck as well making the frame a different part number.

Swingarm is also different, but it's tough to tell if the Breakout swingarm will fit in the Street Bob frame. Fender struts bolt on, so that part is easy. What I cannot find online is the frame dimension where the swingarm mounts. On my 2021 Street Bob the inner frame dimension at the swing arm pivot shaft is appx 9". Tough to get an exact number, but it's close.

Maybe someone with a Breakout can give you a similar measurement. If they are different, I suspect it is going to be materially different.

Zach

Yes if we could get the same measure from a Breakout or a Fat boy. 
9" at the swing arm pivot shaft on the "narrow" frame. Thanks for that