Here's why!
http://www.enginelabs.com/news/video...y-your-engine/

 

That article mostly applies to turbocharged or roots supercharged plain-bearing engines, without sufficient computer controls, some of which can make huge torque at very low rpms.

Low rpm, high throttle operation on a computer-controlled engine with a roller bearing bottom end, which only makes about 1 ft/lb torque per cubic inch (a stock or slightly modified Harley) isn't much of an issue.

Roller bearings are much less susceptible to being damaged by high load and low rpms than "plain" bearings are. For example, roller bearings are what's used for wheel bearings, and we aren't warned that they will be trashed if we drive too slow, because they won't.

Things would be different if we had plain bearing inserts in our bottom ends, or what they call "bushings" in the bearing industry.

 

Yep, on plain bearings once you squeeze out the oil film, you're in trouble. especially with modern oils which keep reducing anti-wear additives like ZDDP.

but the real reason you don't want to lug a Harley is detonation. I once lugged my bike because I had to brake hard to avoid some cell-phone-yakking idiot from running me into the curb. I forgot to downshift and when I tried to get going again (still in 4th gear) I heard "PING-PING-PING" from the engine.

 

Detonation can certainly be a killer, but I've never heard detonation on either of my 2006 and up Harleys, no matter how hard I tried. If I should at some point in the future, the first thing I would do is look for a problem with the computer or engine sensors, and the next would be to look for a problem with some guy who claimed to have done something he called a "tune".

 

I don't advocate lugging an engine. But I rented a '16 Fatboy last week, and there is something uniquely cool about how that balanced engine sounds at lower speeds. As such, I found myself ridding at lower RPMs than I do on my TG ultra classic.

 

Though I try avoiding it on my 14 FLS, my shortened final drive gearing helps quicken the rpm up take to where it aint really luggin?, but mire like a sledge hammerin on an anvil comin from hell.
I love it. There's no pigggin. Just one, not two big slams. Crazy I tell ya

 

I usually keep my bike between 3000-4500. Only in parking lots do I putt-putt around. I like when others lug their motors because that will help the Harley bottom end need a rebuild at 50k. My friends with bike shops like that...

 

What a bunch of uniformed BS. Stresses on bottom ends don't reduce with increases in rpm. They rise.

 

"I usually keep my bike between 3000-4500."


Seriously? I've never even had the rpms in my '93 Heritage up to 4500! No wonder most of you guys buy a new bike every couple of years. Yooz beat the shizz out of them then pass them on to some other unsuspecting victim that buys your trade-ins. I'd say the if you usually live at 4 grand or more then you'll have no problem red lining it regularly.

 

Doesn't lower RPM usually mean lower oil pressure?