Hi,

I'll start off by saying I apologise in advance about all the questions.

I currently have a 2019 Road King 107 which has just gone in for an annual service and I've taken the opportunity to take a Fat Boy 114 for a test ride as I've always fancied one. My Road King engine 'system' is stock except for some V&H twin slash slip ons, whilst the Fat Boy has a stage 1 with V&H slip ons (they look like the eliminator 300's) and I've noticed a few things:-

1. The Fat Boy is noticeably louder (without being crazy), and the sort of volume I want my RK to be
2. The engine of the 114 is A LOT more vibey, I can feel vibrations through the bars, seat and footboards.
3. The 114 feels quite a bit less torquey low down and not as smooth.
4. The Fat Boy rides bumps in the road much better than my RK.

So my questions are:-

1. How much of the sound of the Fat Boy purely down to the Eliminator exhausts and how much (if any) is down to the the air cleaner and remap?
2. Are the vibrations from the 114 common, or is this down to the stage 1 and if I had a stage 1 (or 2) on my RK would I get the same vibrations?
3. Is this normal that the 114 feels less torquey?
4. How much of the better ride quality on the Fat Boy is down to the frame and how much is down to the shocks?

Whilst I like the Fat Boy it does feel a bit small for me and I prefer the riding position of the RK, plus I don't want to put up with the vibes from the FB. Therefore over time I will be looking at making changes to my RK, however I don't want to make it run like the FB I've just ridden. So here comes some more questions

1. If I had the stage 1 done (just need air cleaner and remap) would it affect the way the bike runs (in particular the vibes) and would it increase the sound from the exhausts?
2. Same question for a stage 2 (torque kit), and also would this adversely affect the low down torque like the 114 and also not run so smoothly.

Any advice would be appreciated.

 

Softails have solid mounted engines, touring bikes are rubber mounted. You didn't mention if the FB was a preowned bike , If so,it may have had engine work done to it.
An air cleaner, wont do much of anything at lower rpm,You may pick up a little @ WOT, but nothing to write home about.And the only added sound you will get is the from the intake.
Adding a cam (Harley named stage 2) will change the way the bike runs and sounds, depending on what cam you choose. Go to Fuel Moto's web site and look through the dyno charts to get an idea of how some of these combos perform, for a given cam. Better yet give them a call.
And yes M8's are known to be exhaust system sensitive. There is cause and effect, on changes made with them. Lots of noise to not always equate to better performance. Good luck with your project.

 

Thanks, with regards to the solid mounted engine vs rubber mounted I assume you would therefore expect the FB to have more noticeable vibrations? It is pre-owned so I'll ask what (if any) work has been done when I drop it back off but as far as I'm aware it's just the stage 1.

 

To add to what Jake said, the M8s are notorious for needing a certain amount of back pressure, if they don’t have it…what you will commonly see is a significant dip in torque at lower RPMs.
Fuel Moto has tunable exhaust inserts that help address that problem for some aftermarket exhausts.

A cam really, really wakes up the M8. SE cams are ok, but they are EPA compliant tunes. If you aren’t concerned with warranty and really want to get the most out of your bike, aftermarket cams and tuners will net you a significant gain over SE stuff.

 

Thanks, I'll have a chat with my dealership. Warranty runs out in September so it doesn't concern me too much.

 

I’ve ridden both 107 and 114, and to be honest, I did not notice any difference in power.

 

guessing you didn't ride a fully broken in 114 and up hills at high rpms, higher gears, etc....I had 40,000 miles on my excellent running Stage 1 oil cooled 107....I have over 32,000 miles on my bone stock oil cooled 114 and it does not run out of breath in the above scenarios I mention, like my 107 did...chalking it up to 'no replacement for displacement'..or something else they did but it hands down pulls harder, stronger and longer..I know, sounds like an Ad for Viagra

 

I've found my 114 to be much more fun to ride compared to my 107 - basically same bikes (power train wise).

114 is more spirited in my RGS vs the 107 in the RK

 

right on..same two bikes as in my example above

 

Very interesting. Maybe I had a lemon of a loan bike then, but it was very "lumpy" low down, didn't have that same 'push' out of the corners but did rev harder at the top end.

Riding position wise and handling I preferred my RK anyway, but I was just worried that if I started adding stage 1 and stage 2 kits I'd end up with a similar kind of lemon, but it doesn't sound as though I should.