How can you tell whether you have a narrow or wide primary on your M8? I have a 2018 Softail Lowrider.

 

The wide rear tire bikes......i.e. the Breakout and Fat Boy, have the wide primary.

 

I sat on a Fat Bob this weekend and it has a wide primary.

If you want to know which bikes have the wide primary, look up the wide primary cover on HD’s site and look at the fitment details.

 

Just to verify what I saw in a Laidlaw interview video with an engineer about the new line up I did just that. The Fat Boy and Breakout are the only Softails that list the wide primary. It notes it right in the part description with (wide). It's the inner primary housing that is narrow or wide.

 

The 2018 Softail Slim also has the wide primary. I was under the impression all 18 Softails do? 2018 Touring do not?

 

According to the parts manual the 2018 Softail Slim doesn't have the wide primary.

 

My new 2018 Slim came with the wide primary stock. When I ordered the new wrinkle black, they had to order the wide primary too.

 

Original Primary and Replacement. 2018 Slim

 

Ummm interesting. The part # for the inner primary housing for the slim is 36500104. The part # for the wide primary is 36500114 which is the primary housing for the Fatboy.

 

Its hard to find accurate parts information on the new softails particularly the Slim for some reason. I've slightly modified and or researched other softail model parts to find those that say they don't fit, but end up being the same.