The obsession with low revs on the highway

Whenever a new bike is introduced, members here wail and go on about how high the bike will be revving at 80, 90 or 100 mph.

I don't get it.

Perhaps I trust the manufacturer too much, but I always figure that they have designed the bike to be at an optimal rpm at 70 mph.

However, it seems that everyone always claims it is 'revving too high.'

Why do we dislike bikes revving high? Is it longevity concerns? Vibration? Noise (that can probably be fixed by putting the stock pipe back on). Or just a subjective aesthetic concern?

Quite simply, they are brick stupid..


They don't understand that the wind resistance increases exponentially the faster you go. Their bike goes just fine at 10 mph in second gear at 2,250 rpms... So 3,500 at 70 mph is ok.

They don't understand that all engines have a sweet spot.

They don't understand that you need to hold the next gear a little longer than the last one as you accelerate.

They don't understand they are lugging their engine riding in top gear around town at 50mph.

They don't understand that the manufacturers put TALL gearing on the bike to pass emissions.

They can't comprehend that an engine can return better fuel economy and a longer service life if ridden at speed at a higher rpm. It goes against everything they "know".



That is all.

Low RPMs are less "stressful" on the rider when doing lots of miles.

How?

They don't stress about their bike revving...

Its just the way it is.

Go ride a 250cc bike 70 mph at 6500 RPM's for 500 miles on the freeway, then ride a big displacement cruiser 70 mph at 3000 RPM's for 500 miles on the freeway.

It will be self explanatory.

Perhaps your riding style and choice of bikes has been limited in scope and you simply can't appreciate things outside your experience?

You may want to reread the first post again.
He wasn't talking about two different size bikes.
Or else I completely misread the post...but I don't think I did.



Peak torque for my bike is 7250 rpm, this puts the bike right at 70 per cent of the 10,500 rpm range.
I think they got it spot on for highway cruising.

I took it to be a generic question about high RPMs, maybe I was mistaken.

I have owned a lot of different bikes in many configurations, and have found the ones that can cruise at lower RPMs to be more relaxing to ride for long distances.

I was simply relating my personal experiences and opinions.

my VFR sits on 5000rpm at 120km/h. Humms my balls nicely. Why change that?

Many bikes are designed to rev and there is no effect on longevity. Those bikes are typically very much over-square, big bore, short stroke. The manufacturers know what they're doing.

I understand why people want their bikes to run lower RPMs on the highway....noise and vibration would be the two big factors. IMO high frequency vibrations will fatigue the rider faster than low. I think the other misconception is they feel the bike is underpowered or geared wrong when the RPMs run high.

It all depneds on what the bike was desinged for and the engines size. My little 4 banger Ford runs at 3100 RPMs at 75 MPH....my big Dodge pickup with a V8 runs the same speed at 2200Rpms....I don't fault the Ford for that...its got half the engine but also gets 3 to 4 times the MPGs....

Ride more, worry less....

Sound is important. You have to love the sound.

There is less engine wear and lower fuel consumption at low RPM above the engine minimum full load RPM which can vary. This is the minimum RPM where the throttles can be fully opened and not cause excess bearing wear. Lugging an engine, is bad. Spinning one fast does use more fuel when running at part throttle. High RPM camshafts will lose efficiency at lower RPM. This is why variable valve timing is now popular.

The engine mfg should have a set of fuel consumption per horsepower curves. As you change camshafts etc for higher power and RPM, the minimum fuel consumption point moves to a higher RPM. This is why some of the little 600 sport bikes get such awful fuel economy.

To me the character of an overdrive low RPM bike is less tiring on a longer trip. I will trade off a little peak power for that or get a variable valve timing bike, and live with the increased complexity. YMMV

Rod

what is low revs

middle of the tach?

The handbook that came with my bike had a set of charts included for torque, horsepower, hill gradients and gears, fuel efficiency. The most interesting to me was torque. The engine redlines at 5,750, maximum torque is 3,500-4,500, and best fuel efficiency is within that range. At 50 mph I get 80 mpg, at 57 I get 70. 57 is maximum cruising speed and redline. What seemed remarkable to me was the accuracy of the charts on such an old machine. I climbed a long 5% grade on the Interstate in high gear and maintained a minimum of 45 mph, exactly what the chart predicted, max grade and max torque. The engine was in perfect condition with the advantage of synthetic lubricant. I had not intended to be on that section of I-89. I got on one ramp too soon. :eek1

Halfway to red line on a Ninja 250 would be 7,000 RPM. Red line is 14,000. Middle of the tach would be 8,000 RPM as the tach goes to 16,000. Yes, it's a very over-square engine with a 62mm bore and 41mm stroke. Try riding one at 3000 RPM and you'll get nowhere fast.

If you ride a low RPM bike it feels strange to ride a high RPM bike but eventually you get used to it and it feels normal. I love the sound of my old GL500 V twin at 9,000+ RPM which is where the max HP is.

I am gonna start ridin my Harley on the highway banging off the rev limiter at a screaming 5500 RPM


....now the FZ6 I used to ride didn't even wake up until 8,000 RPMs.

If it isn't leaking oil out the seals, I fail to see the problem. I had an '83 XL185 that would spit oil all over my legs at anything over 55 mph.

My KLR vibrated like shit at high revs. 5000 rpm was the limit of me having a good time, and I didn't pass it (about 65 or 70 mph in 5th)unless I wanted to get somewhere fast or needed to not get run over.

My Tiger 800 doesn't vibrate ever. At 70 mph I'd rather be in 4th gear than 3rd, but it doesn't care.