Power & Torque

My journey from Road Glide Limited to Low Rider ST

by Axel Thill, May 2022

FXLRSTcomp.jpg

Let's talk Power and Torque

In my previous chapter Less is More, I talk about downsizing, and I meant downsizing in weight. Moving to a 2022 Low Rider ST, I am actually upgrading the power unit, as the FXLRST - like the FXLRS - features the 117 cubic inch Milwaukee Eight, the first time this engine is standard outside the CVO range.

Here a quick Thank You to all CVO riders for acting as guinea pigs for this engine and curing it from the gremlins of every new launch. Let's consider the 117 power to be proven, tested and ready for many Stages of upgrades.

 

Sorry, need to write down some numbers: speaking mainly European languages, 117 ci are understood to be 1,923 cc, 114 ci are 1,868 cc, an increase of nearly 3% and more than most family cars. Stroke remained unchanged at 114.3mm, no surprise, as a change here would involve more expensive internal parts. All Harley did is increasing the bore by tiny 1.5mm, from 102mm to 103.5mm, introducing bigger pistons. Thanks to the massive stroke of a Harley engine, this 1,5% increase in bore leads to 3% increase in displacement. 

The power increases from to 87hp to 105 hp (+20%) is substantial, while the torque increase from 160Nm to 168Nm (+5%) is moderate. Power is for speed, torque for acceleration, I personally can't get enough torque, the top speed is not so relevant for riders who love to keep their driving licence. But the power increase is welcomed and surely due to a improved mapping.

Will you feel this increase by 3 % or 5% of torque? Having only tested the FXLRS so far, the clear answer is yes, YEES, 100% yes, stock, standard, as out of the factory. But not because my bum is so sensitive to feel the change in engine strength, but because this increased strength is used to move 22% less weight. One horse power had to move 4.8kg of Road Glide, now it needs to move slim 3.1kg of Low Rider ST, or 35% less weight per hp. And that is what you feel.

But no need to remember all these numbers, as soon as you change something, anything, like pipes, mapping, cams, bore, or a visit to Dyno, and the numbers change. One example: the Road Glide ST (same 117 engine) has less power than the Low Ride ST, the visible difference of these 2 bikes are the pipes, the invisible difference could be the mapping,

 

Note to self: less weight with more power,  Va Va Voom

vavavoom.JPG

And then there is Harley-Davidson playing with your numbers, or your H-D dealership technician, in order to make local environmentalist happy.

 

Note to self: only my Harley coffee mug has the right answer to power and torque analytics

I was a rider who enjoyed spending cash on pipes, filter and mapping for a Stage 1, and still believe that "Loud Pipes Save Lives". There is a lot of political correct opinions on this, pointing out that car drivers do not hear you anyway or your noise is directed backwards, but its not so much about my life, but inattentive pedestrian with earphones and cyclists hear you. Noise is good for them and me when sharing the same space.

But I admit, after some zillions of long distance miles, a headache started to appear after 300 miles a day, and quiet inserts were installed. I like to hear my audio from the speakers, and am looking forward to the Rockford Fosgate Inner Fairing.

Read also related posts of my journey to the Low Rider ST:

Less is More

Rockford Fosgate

Garmin Zumo