Don't lug yer motor...
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From: MASS_hole
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From: Detroit
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.
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.
Last edited by Warp Factor; Aug 20, 2016 at 01:19 PM.
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From: Detroit area
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.
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.
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From: Detroit
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.
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.
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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.
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I love it. There's no pigggin. Just one, not two big slams. Crazy I tell ya
Last edited by splattttttt; Aug 20, 2016 at 09:39 PM.
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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...
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What a bunch of uniformed BS. Stresses on bottom ends don't reduce with increases in rpm. They rise.
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"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.
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.
Last edited by Hey Man; Oct 10, 2016 at 06:08 PM.
