Keeping the revs up......

[co_g30]

Once again illustrating how much of a neophyte I am in the way of motorcycles....

 

I recently went riding with a co-worker and during one of the stops he mentioned how he likes to "keep the revs up" as he rides in order to get the best performance from his bike, specially in the twistys.

 

I've taken this to mean keeping the bike's rpms, at least on my 1150RT, at or near the 4k mark instead of what I used to do which was shifting up to the next higher available gear in order for the engine to not work so hard.

 

I do find that in the twisties it gives me good engine-braking potential and of course makes it easier to accelerate out of the turn; course this is with the accompanying slight drop in mpg.

 

My question is this: Do you more experienced riders do the same, keeping your bike revs up, not only in twisting roads but during city driving? Or do you move as fast as possible to highest gear that keeps bike from being below 2k in RPMs and working less hard?

[RussL]

I keep my revs high in the twisties (tight stuff, not sweepers), but move to higher gears in my around town riding for better gas mileage. However, I dont lug the engine (run too low of rpms). You never know when you're going to need a quick burst to avoid a traffic hazard.

[GelStra]

Good question. For me, it depended on the riding at hand. Cruising on the freeway, the bike was at 4K, which on the 12 is right in it's sweet spot. I can't remember where I read it a while back, but the writer commented that "revs are your friend." And I did that when chasing Russell or Steve through the twisties. Great engine braking, great sound, always in the meat of the loud handle. Off road at slower speeds, 2nd gear is the Swiss Army knife gear on the 12GS. You could lug it down to just above idle, wind it out, eliminating the need to be constantly shifting in the bumpy dirty stuff.

So, I guess, match the gear to the ride. And revs are your friend.

Next?

[ShovelStrokeEd]

On my BMW's I tend to keep the revs in and around the 4K range almost all the time, city or rural roads. In fact, you could almost say I don't drop much below 4K and tend to run between 4 and 5K. My freeway speed tends to keep the bike up in that range as well. On twisties, I tend to just run one gear or maybe two and it is usually one of the lower gears, third most often. The engine, btw, is not "working hard" at those RPM's. In fact, it is working less hard to accelerate when in the lower gears.

 

The Blackbird is a bit of a horse of a different color. It has much more power and torque than the boxer twins and I tend to run it in a little higher gear (lower RPM's) than I do the Beemers. Third gear is still the primary gear for twisties but I tend not to downshift for the slower corners and kinda keep it out of the powerband which hits hard at around 7K RPM. This greatly reduces the tendency to spin the tire on corner exits and thus makes for a bit less thrilling of a ride.

 

I really don't notice any fuel consumption penalty from this practice and, since I stay a long way from the surging range (3K RPM), my bikes never surge. In fact, the best fuel consumption I got on my 1100S happened when riding the Blue Ridge Parkway from end to end, in third gear almost the whole time. The speeds were not high as my goal was to average 50 without going over 55. Got 46 mpg for the trip (about 450 miles) on a bike that averaged 39 mpg over much of its normal riding. I think its worst was a couple of passes through Deals Gap and a run over War Woman Road where the revs were seldom below 6K and I was really being aggressive about corner exits. 26 mpg there. About what the Blackbird gets in town.

[peterh]

I keep my 1150rt between 4-5K rpm, except when in town, then I drop below 4K. I have found over time that when riding without paying attention to engine speed, I naturally run ~4-5K rpm, where engine vibration becomes minimal and the bike 'feels' the best. On back roads or when cornering, I use the transmission simply to select my speed while keeping the engine in the sweet spot.

 

peterh

[Bob Palin]

The oilhead motor is designed to be revved, at 4K it is just getting comfortable, below 3K you are lugging it - don't do that! Above 5K it is happy, at 7K it's ecstatic.

[milesandmiles]

I notice my 1100RT likes to stay in 4th at normal highway speeds, at least until I can get it up to around 65-70 mph. 5th gear is happy up to about 90, then I get a buzz. I guess that's where 6th gear in the 1150RT comes in handy? When do the rest of you 1100ers like to shift?

[Tony_K]

1100 5th is ideal in the 80's to well over 100.

60 to 70ish is putt putting with a delay in power up to quicken speed.

 

Enviroment dictates gear for me. 3rd to 4th a lot of the time in L.A.'s road warrior conditions. That's when you can get into those gears. Ugh.

 

As for buzz. I guess I don't know what that is. Oh yeah... I'm often riding things that shake the teeth out of your head and leave your body like a limp noodle after a 30 min ride. A buzz would escape me.

[pbbeck]

I've been riding boxers for several years, and I find that in the last year or so, I have been riding my latest (1200 GS) higher than I used to in all situations. In city driving - I do a ton of city driving - I'm mostly in the 4-5K range, trending closer to 5K. I feel safer being in or at the verge of the meaty part of the power band, as it gives me a tactical advantage if I have to move QUICK!

 

I also find that I have developed a set of rules regarding shifting the GS:

 

City/Congested Traffic - I treat the bike like it's a 3-speed.

Freeway/Moderate to Heavy Volume - I treat the bike like it's a 5-speed.

Wide Open Freeway/Highway - Then, and only then, do I use 6th.

[motoguy128]

I typically have very little traffic and enjoy a nice relaxed ride, so I keep the revs between 2500 and 3500,, just relaxed crusing. The boxer seems a little viby and unsettled much below 2500. for turns or for extra engine braking, I'll downshift. I usually blip the throttle and downshift through all the gears including first as I slow down. Probably a habit from my 600cc sportbike riding days.

 

Either way, my fiancee has never complained about a little extra vibration form revving the bike out.

[Bill_Walker]

Keep it above 4K and it'll be a happy bike.

[ESokoloff]

I keep the revs between 2500 and 3500

 

Sounds like you might be lugging it a bit.

 

I keep it above 3k.

For me 3-4k is cruising range.

[sardineone]

I'm riding a R1200 so results may vary from your 1150. My R12ST is strong anywhere above 3200 RPM. In town when not in a hurry I stray down to 2500. In the twisties I really don't need to wring it's neck to go quite fast usually 3500 - 5000 in general. With that said and under the advise of a 'A' rider friend on a R12GS I kept my bike in 2nd on US129 @ 'Deals Gap' last fall. Just right for your previously mentioned engine braking and response out of the corners. That's a fairly extreme case of a tight curvey road but, the boxer twin seems to thrive on hard running. So in the end rev higher if you need more engine breaking to setup the corner, otherwise just don't lug it in the twisties. Just my opinion.

[BWS]

I like keeping my BMs in a very "fine" state of tune,mechanically and whilst strafing.As such its important for my mental sharpness to be at an RPM that allows instant fr-rr weight jacking.IOWs,keep the revs at such a point that giving just a touch more whip will get weight on rr.Furthermore....precisely where the gas gets picked up and how smoothly is much more attainable when keeping bikes revs in the sweet spot.I really strive to not engine brake,the brakes do a lot better job at transfering weight fwd,but it(engine brking)still figues in from a timing standpoint.

 

Best of luck,BW

[AviP]

High revs in the twisties or during aggressive riding, low revs on straight roads.

[Alan D]

I learned that 3rd gear, running from 4K to 6.5, works for me in the twisties. That allows plenty of engine braking before the curve, plenty of power to accelerate out of the corner. I work on trying to be smooth and slow in and fast out. On my 1100 those rpm probably relates to 40 mph to 70 mph. (I'm usually looking at the road.)

[RevRay]

Revolutions are your friend, keep them up

[chemman]

If find the bike feels like it's lugging below 3K. For just cruising around on the way to and from work, generally keep it between 3-4K, except on harder acceleration. On the open road, skys the limit (almost). I won't touch 6th until at least 70 mph and accelerating at that.

[ChrisM]

The 1100RT (with the GS tubes)has an incredibly satisfying surge of power right around 6000 rpm and up....something of a motivator to keep the revs pretty high when riding aggressively. Keeping the revs high seems to save a bit on brake pad wear as well...a fair amount of speed can be sloughed off just by untwisting the throttle (but for safety's sake always keep in mind that suddenly backing off the throttle, particularly in lower gears, can be just like sharply applying the rear brake).

[Laura]

I keep the revs between 2500 and 3500

 

Sounds like you might be lugging it a bit.

 

I keep it above 3k.

For me 3-4k is cruising range.

 

 

I'll say! At 2500-3500rpm it's voice gets a lot deeper and you can tell it just doesn't like it.

 

The more miles I accumulate the more I get with each gear and now I don't consider keeping the revs up until I'm over 4300rpm. Sometimes I'm riding at 5000+rpm and it feels like it used to feel at 4000rpm.

 

In the twisties I prefer keeping at the top of the gear and using throttle control. In the sweepers I prefer a little more relaxed rev for a nice smooth relaxed ride.

 

Slow speed manuevers require keeping the revs up to prevent the ole Burpendrop.

[Paul De]

Definitely want to keep the RPM above 3,000 on the oilhead for good drivability. Many folks make the mistake and run the boxer motor in a gear to high. Unlike the long stroke V-twin motors found in most cruisers, boxer motors are short stroke and perfer to be rev'd. Boxer motors develop most of their power in a much higher RPM range than a cruiser v-twin motor. In fact it is harder on the boxer motor to lug it than it is to let it spin up into the 4,000 to 6,000 RPM range.

 

Like many have said on this board before....drive it like you stole it.

[ShovelStrokeEd]

I think, if you were to compare dino graphs, you would find that peak torque occurs at an RPM above peak HP or even red line on most cruiser motors.

 

It really is not about keeping the revs up so much as keeping the motor in a useful range of RPM so that it may accept throttle with grace and a lack of pinging or shuddering.

 

Sure, 4000 RPM sounds high to someone who was raised on a motor that had a 5800 RPM red line. In proportion it is equivalent to 2980 RPM on the other motor. In other words, right in the mid range.

 

My Blackbird actually considers 4K a bit low, much preferring 5K or higher as a cruising RPM range and shift point. Of course, it also has a 10,800 RPM start of red zone with the rev limiter kicking in at 11,400.

[philbytx]

 

When in the twisties I try to keep it humming between 5 and 6k as peak Torque is around 5500.... and remember that peak HP on the boxer is around 7200

[co_g30]

thank you all who've posted for your expertise and replies....took my 1150RT in some twisty roads today, kept the rpms in the 4-5k range and she ran sweet.

[DouglasR]

Both of my boxers have the 4000 rpm "sweet spot", and will pull like tractors from 3500 to redline. I like to pick a gear and leave it there when I'm in serious twisties, using the whole range and rarely touching the brakes. Yes, I know rolling off the throttle quickly is like hitting the rear brake, but I try to be smooth on the throttle, smooth through the turns, and smooth back on the throttle. If I need the brakes they are nice and cool and ready to do their thing.

 

I read in this month's Cycle World that Team Suzuki is testing a new V-four 800 for MotoGP next year that will rev to 19,000 rpm.... in a four stroke, pneumatic-valved engine. Think about that....

 

I used to race leetle 125 and 250 two stroke motocrossers that revved to 14,000+, no harm. I have a K75 that runs at about 1500 rpm faster at a given speed than the boxer twins; it has 55,000 miles on it and purrs like a kitten.

 

I don't think you can hurt an engine running it within it's design specs, so I run mine as hard as I want without worry. I don't think there's ever been even a spec of carbon in any of my engines!

 

Doug

[Rev. Jerry]

I have an 04 R1150RT, which I usually ride in to 3000-3500 rpm range, being a minister, I obey the speed limits. That means most of my riding is between the 60-70 mph range, which I usually ride in 6th gear. A question: has anyone kept track of long-term engine life at various rpm ranges? I bought mine new and expect to ride it a long time. Right now it only has 17k miles. Would engine life be better if I rode in 5th at those speeds? Peak torque is at 3000 per the book, right? Seems in my opinion that engine wear would just be increased by riding in 5th at those speeds. Of course, I know "lugging" it is also bad, causing piston and ring land damage, maybe even flat spotting on the crank. Anyone have any hard data to offer on the subject?

[Stan Walker]

Peak torque is at 3000 per the book, right?

 

Wrong, it's at 5500 rpm.

 

Would engine life be better if I rode in 5th at those speeds?

 

I don't think so, not as long as you down shift before hard acceleration.

 

Anyone have any hard data to offer on the subject?

 

Not that I've ever seen, and I've been riding RT's since 1996.

 

I will say that I spend a lot of time in the 3000-4000 rpm range. I've got over 82,000 trouble free engine miles on my '02 and another 75,000 on Jan's '96.

 

Stan

[Joe Frickin' Friday]

Anyone have any hard data to offer on the subject?

 

No real-world durability data, but here's some calculations for your consideration.

 

R1100RT engine, specs from the manual:

bore = 3.898 inches

stroke = 2.776 inches

conrod length = 4.921 inches

 

Suppose we run the engine at 7000 RPM. what is the force on the wristpin and crankpin, due to inertial loads only, as the engine goes through TDC?

 

At 7000 RPM, the crankpin's centripetal acceleration is 1930 g's, and the conrod's end-to-end acceleration is 548 g's. So the total piston accel is 2478 g's; if the piston weighs 1/2 pound, then the force on the wristpin is 1239 pounds. If the rod weighs 1 pound, then the force on the crankpin is 1239 + (548 * 1) = 1787 pounds.

 

Now suppose we run the engine at WOT. What is the force on the wristpin and crankpin, due to combustion loads only? Peak cylinder pressure is likely to be around 750 psi; given the above bore, the force on the wristpin and crankpin works out to 8950 pounds.

 

Of course you won't see peak torque if you're down around 2-3K RPM, but you might see 2/3 of it, still quite a bit more bearing load than what you'd get from inertial loads if the engine was running at high RPM.

[Mark_Turner]

Geez Mitch, what are you some kind of a rocket scientist? People on this board sure know how to make a average guy like me feel stupid!

 

Leaving tomorrow to ride from Cleveland to Deals Gap and then onto the outer banks of NC. Will be back in ten days!!

Yippee!!!!

 

Mark

[ShovelStrokeEd]

Actually, I think Mitch is a diesel scientist or maybe better an internal combustion engine scientist but a scientist he is. One with a knack to getting to the heart of the matter thanks to his discipline.

 

Nice explanation, whoever you are today.

[movinguy]

Guy at the dealer told me I should keep the K1200RS in the power band between 5k-7k or I'm lugging it. Runs great up there but the guy I bought it from put a Two Brothers header and pipe on it and it's LOUD . . .

[Lawman]

Anyone have any hard data to offer on the subject?

 

No real-world durability data, but here's some calculations for your consideration.

 

R1100RT engine, specs from the manual:

bore = 3.898 inches

stroke = 2.776 inches

conrod length = 4.921 inches

 

Suppose we run the engine at 7000 RPM. what is the force on the wristpin and crankpin, due to inertial loads only, as the engine goes through TDC?

 

At 7000 RPM, the crankpin's centripetal acceleration is 1930 g's, and the conrod's end-to-end acceleration is 548 g's. So the total piston accel is 2478 g's; if the piston weighs 1/2 pound, then the force on the wristpin is 1239 pounds. If the rod weighs 1 pound, then the force on the crankpin is 1239 + (548 * 1) = 1787 pounds.

 

Now suppose we run the engine at WOT. What is the force on the wristpin and crankpin, due to combustion loads only? Peak cylinder pressure is likely to be around 750 psi; given the above bore, the force on the wristpin and crankpin works out to 8950 pounds.

 

Of course you won't see peak torque if you're down around 2-3K RPM, but you might see 2/3 of it, still quite a bit more bearing load than what you'd get from inertial loads if the engine was running at high RPM.

 

What Mitch said.

[Bill J]

Guy at the dealer told me I should keep the K1200RS in the power band between 5k-7k or I'm lugging it. Runs great up there but the guy I bought it from put a Two Brothers header and pipe on it and it's LOUD . . .

 

What guy...a mechanic? I'm no mechanical engineer, but I have do ride a K-bike. Riding below 5,000 is not lugging the engine. The bike may not like full throttle at 2,000 RPM in 6th gear, but it doesn't have to be above 5,000 RPM all the time.

 

BTW, I like the sound of the stock exhaust, and the bike starts to make musical sounds around 5,000 RPM. I'll bet you can find someone who'll trade you a stock exhaust for your 2 Bros .