Wearing-In Your RT
by Richard D. Frantz 



This article has been written primarily for owners of the BMW R1100RT motorcycle. The specific mileages, engine speeds, and oil types mentioned apply directly to it, and the other members of the oil-cooled boxer-engined family.

However, the dynamic factors, the general nature, and the specific methods, if not the precise operating magnitudes apply to all new motor vehicles. Parts is parts.

You should follow the the recommendations of the manufacturer of YOUR vehicle. But, understand,  the process outlined herein is most likely MORE STRINGENT than those recommendations. Consequently, these recommendations suggest, but not direct you to be MORE CAREFUL than manufacturers generally direct. Lucky for you, huh?


First, I want to state that I HATE the term Break-In. I don't want ANYTHING on my vehicles BROKEN. Worn: Yes. Broken: No. What we're after is to WEAR the new parts down so they mate well - WITHOUT damaging the vehicle.

"Wear-In" helps us focus on the POSITIVE aspects of the process, and the desired eventual result.

The new vehicle process is to WEAR-IN the parts efficiently. One "runs" the vehicle, so Run-In is appropriate too.

The treatment a new vehicle receives is a large determinant in the quality of service it returns across its life span. It's perhaps an even more important factor than which oil is used and how often it's changed (within reason), or how "hard" its driven across that time.

The motive parts of modern vehicles are constructed from materials, and receive surface treatments, that make them very durable. But, the condition of those surfaces after they are machined, and even polished, is still much rougher than is optimum for both ultimate performance and longevity. If the roughness is not removed, or, God forbid, enhanced, the vehicles will return poor service, and require much earlier rebuilding or replacement.

The Wear-In process is designed to remove that roughness in order to produce the lowest friction, and thus wear, during the heart of the vehicle's life. This initial operation must be done in a way that does not promote damage.

Across the years, countless experts have clearly stated the Policies you'll encounter here. Yet for some reason, they don't get clearly, and consistently communicated to the vehicle operating public.

I've listened to some folks tell of buying their new car, truck, or motorcycle, and then just driving off and continuing to run it "like they always do", and "nothing bad ever happened". Their Ducati got traded in at 40,000 miles, or their F-150 at 80,000, or their Toyota at 100,000 because "well, it was getting a little 'old'".

I buy new vehicles every two years or so. BUT, these "passing fancies" live with one or more units from the motorcycle, car, truck categories that are TWENTY-FIVE YEARS OLD. Their AVERAGE mileage is TWO HUNDRED THOUSAND MILES. I don't intend to rebuild their engines, or to replace any of them soon either.

Certainly, good results like that stem from a good care program overall. But "overall" includes the "start of cycle" part, and that had to have been good too.

Here's what it was.

Adding Oil:

When new, tolerances in the engine and drivetrain are larger and less precise than when Worn-In. Some believe they are tighter (and some in fact are). Measurements taken SEEM to confirm this. WhatÕs happening is that roughness, UNEVENNESS of the surfaces exist after machining, and even honing an lapping. The SUM of the tolerance between ENTIRE surfaces is greater than the measurement because of bumps being read rather than the true matching surfaces.

In particular, your cylinder bores are not round. Whether they ever get to be round, we know that right now, the rings are not fully touching the bore EVENLY. SameÕs true with the valves vs. the valve guides and oil seals. You WILL use oil.

However, were the oil level to drop to a critical level, UNWANTED contact of surfaces could occur. The subsequent galling is irreversible.

Check your oil every 50 miles
After running 50 miles, let the bike sit on the centerstand on a level surface for about 10 minutes and check the oil level in that stupid window. Add oil to its CENTER POINT. Higher oil levels do NO good. The oil is wasted because it is ejected - probably coating your catalyst and the Oxygen Sensor. Poor running results.

Too high an oil level has also been linked to rear crankshaft seal failures in the R1100's. That's not uncommon in other vehicles as well. It's just easier to do on the BMW's because of the poor oil level measuring device the factory did provide, and the clear and precise directions it didn't supply.

In the BMW R1100's the oil capacity is four quarts. The majority of that is used for cooling rather than lubrication, and there's more than needed for both. Consequently, running with an oil level a LITTLE low causes no problems.

Across the short 600 mile span the Wear-In oil is present, seldom does a rider consume enough to warrant addition. However, my VIGOROUS application of the process, and its conduct in the hilly, and winding roads of King Canyon and Sequoia National Parks meant I was under deceleration much more than is normal. My oil level reached the minimum.

BMW placed a very LIGHT weight oil in the crankcase, and possibly the transmission and rear drive. It's purpose is to ALLOW the moving parts to achieve contact, or at least high pressure. They WANT things sliding around over one another so the Wearing-In process occurs more quickly.

The materials, and surface treatments they use are somewhat harder (at least more durable) than is common in the motorcycle industry. This promotes longevity of the product. This also LENGTHENS the Wear-In time. With time comes the probability an injurious or destructive event might occur.

The lighter oil speeds the process. It also carries away the worn off metal better, and allows the oil filter to remove it more easily. Mixing some OTHER kind of oil defeats the purpose.

As well, ANY other oil is NOT LIKELY to be compatible with the Wear-In oil. It may not mix properly, and run through the engine as gobs that DISRUPT the average tolerances, and then allow a "slam down" contact to occur.

As well, its "wear saving" additives (not present in the Wear-In oil) WILL get deposited on working surfaces. Again, this slows the Wear-In process and leaves us liable to damage.

If you think you MIGHT be under deceleration much of the time, get a pint of compatible oil from your dealer.

Throttle Handling:

The general admonitions to "Avoid constant throttle settings", and "Change speeds often", fall short of communicating what the operator should do and HOW.

Most people focus upon NOT HURTING the machine during Wear-In. Good, but not Best.

Instead, there are things to do that ASSIST the Wear-In process, and thus decisively improve the machine's characteristics further down the road.

Avoid large throttle openings
With any running, those rough places will wear down, and better mating of all the shearing and sliding surfaces will take place. However, in the case of the cylinders, HIGH INTERNAL PRESSURES, as with low-speed, full-throttle operation, RAM one or more of those rough spots into either the rings or cylinder walls, and SCAR IT. ThatÕs true for any of the mating surfaces too.

Were that to occur, it might take the normal wear of 100,000 miles to Òpolish it outÓ - if ever. In the case of the cylinders, power would be lower, and oil consumption higher as gasses and oil escape through the gaps. In the case of gears, vibration and whine would persists.

AGGRESSIVELY alter the throttle position AS OFTEN AS POSSIBLE
At a given load and speed, matching parts wear across a given area. A different speed means a different area is involved. Consider that at 50 HP the piston and rings are driven down X inches. At 75 HP they're driven down farther because the applied force compresses the piston and rod, and stretches the crank throw. It also slams the crank harder into the journal bearing. Different places get touched. Minutely, but definitely.

If we run the engine at a constant RPM only THAT area gets "wiped" and worn. Later, if we run it faster, the rings will have to "climb a hill" to get out of the smoothly worn rut. As they do, inertia will cause them to reduce pressure on the cylinder walls, or separate entirely. Blow-by occurs, and power is lost. But worse, gas cutting, "etching", occurs on on both surfaces. Now the rings will NEVER seat, and the condition will worsen.

That's avoidable by revving the engine UPWARD with a "high" throttle setting, not just "rolling" the engine up to some higher speed. The "high" throttle opening produces a high internal cylinder pressure, forcing the rings against the cylinder walls. That promotes sealing that prevents gas cutting, and also enhances the wearing contact we're striving to achieve.

When the higher RPM has been reached - HOLD IT THERE MOMENTARILY. Keeping it there, in this new, "poor contact" area leaves us open to gas cutting and mechanical galling. So don't tarry. But DO get up there - and POLISH.

Then, CLOSE THE THROTTLE FULLY to decelerate to a lower RPM. This creates the lowest possible pressure in the cylinders, which will DRAW OIL UPWARD to lubricate and clean the "new area".

Closing the throttle also produces the greatest DECELERATION. That means the driveline component matching surfaces, get to visit "new areas" on the OTHER side of the scale. Thus they run more smoothly in the "common" range you'll use in your mature vehicle.

To repeat: CONSTANTLY, that is EVERY MINUTE you're on the road, Rev Up Smartly; Hold; Close Down FULLY.

Run from 3000, up to 3,500, and back to 3000 RPM. Repeat, repeat, repeat, ad infinitum.

If you notice this disturbs or irritates drivers behind you, change lanes, or pull over and allow them to pass. IT'S YOUR VEHICLE. Get it running right for its LIFETIME.

GRADUALLY  increase maximum engine/vehicle speed GRADIENTLY throughout the process
What we're trying to achieve is a sort of "groove" where matching surfaces "come to meet and play" during NORMAL operating loads. We want those surfaces as SMOOTH as possible. That will provide "smooth operation", and low vibration, of course.

But, it also will provide the best sealing, and the best "lubrication bed". Sealing will reduce fluid passage and/or consumption. Fluids include the combustion gasses (blow-by: gas cutting), and oil (blow-by: oil loss). A smooth lubrication bed allows those tiny strings of oil molecules to run out onto the floor, all join hands, and act like a trampoline to keep matching parts from contacting each other.

Were one to wear-in the surface area associated with "3000 to 4000 RPM", and then suddenly run the engine at 5000 RPM, it would "jump the slope" as mentioned earlier. MUCH better to "slowly eat away" at the ridge that has formed just beyond the 4000 RPM spots.

Cut the ridge away slowly. Then cut some more, and so on. A relatively good model might be:

Vehicle Mileage Maximum RPM
0 - 200 3500
Up to 600 4000
Up to 1200 4250
Up to 2400 4500
Up to 3000 5000
Up to 4000 5500
Up to 6000 6000
Up to 9000 6500
Up to 12000 7000
Beyond 12000 YELLOW Line

You might consider that a LONG time to Wear-In a vehicle. My justification for that program stems from a Porsche owner who raced in the SCCA South-East region in the 1960's. Porsche made him a deal on the newly introduced 911, that he would drive on the street, AND in competition. This Wear-In program allowed him to continue to RACE his vehicle all the way to the 100,000 mile mark. Ultimately, with a single engine rebuild, he ran and raced the car to 200,000 + miles. No transmission rebuild either.

The second justification comes from my racing cars. I Wear-In my Ford V-8 motors for 100 hours before they're installed in the race car - about 8,000 miles. They last over 60 hours of racing. That's 2.5 Le Mans races, guys!!! The savings in rebuild cost (US$15,000 - $25,000) allowed me to buy the needed track time, and a "mule" for the Wear-In, as well as testing components and settings. Roushe hates it. But my cat loves the extra cat food I can buy.

You'll notice in the chart that the mileage SPAN at a given RPM increases. That's because you will have changed out the Wear-In oil, and the heavier oil will decrease the pressure and contact of matching surfaces, thus slowing the wear process. Your "high" throttle acceleration will overcome that thicker oil barrier and continue the Wear-In process.

Then, because the surfaces are more highly smoothed during any increment of the process than if done for a lesser duration, the wear rate slows down, and finally reaches a point where you can happily run the engine a full throttle up to Yellow Line CONSTANTLY, and not experience much wear at all. That's what RACING is like,

Don't quit the process too soon
My V-4 Honda 1100cc Sabre has 225,000 miles on it. When the heads were removed to do a valve job recently, the cylinder bores looked like those of a typical 20,000 mile vehicle. Good oil and frequent oil changes helped. But, my Operation Policy is the strongest reason for such good condition.

Despite having a 10,000 RPM Red Line, I never operate the engine over 7,000 RPM. My normal shift point is 4,000 RPM, and 5,000 when I'm in a hurry. At those engine speeds, I can walk away from ANYBODY'S BMW R1100RT on torque alone

HOWEVER, when I ride I STILL set aside SOME time to run it up and down the rev range as if I were Wearing-In a new motor.


I notice that every time I take my BMW R1100RT up on Angeles Crest (our local Nurburgring), when I come back, it's running more smoothly, and quietly. Up there: One third of the time I'm under nearly full throttle; One third of the time I'm at constant throttle; One third of the time I'm at closed throttle. Decelerate up to the turn - Constant throttle on toward the apex - Full throttle out of the corner. Hours on end. Boy am I lucky.

One More Thing:

Warm Up
Typical advice about an air or oil cooled engine is to start it and drive off,  then drive moderately until operating temperature is reached. That's supposed to get the engine to operating temperature most quickly, and thus expand things to their best tolerances. Less wear that way.


Tests show that running an engine at about 1250 rpm, with no forward (cooling) motion, warms it up fastest IN A MANNER that produces the LEAST WEAR. This is according to the engine builders for MG and Jaguar, circa 1968.

In 1982 I bought two Honda Civic CRX's, for my (ex)wife and myself. We drove the same route to work  (a tough mountain commute), except for the last 7 miles. Hers needed an engine rebuild at 80,000 miles. Mine was traded-in at 125,000 miles with no rebuild.

Religiously, I warmed my engine up before driving off. She didn't.

Whether new, or mature, engines wear less destructively if warmed up properly before normal operation.


Ensure you always operate with a sufficient quantity of Wear-In oil ONLY. Then, after the first oil change, keep the crankcase/sump filled with CLEAN oil AT THE PROPER LEVEL.

CONSTANTLY rev to the Current RPM Limit under "high" throttle, hold the RPM level for about 10 seconds, and then close the throttle FULLY until the starting RPM is reached. Constantly means ALL THE TIME.

Increase the Current RPM Limit GRADUALLY across the Wear-In period.

Continue the Wear-In actions across the life of your vehicle.

Warm your vehicle up at 1250 RPM, at least until a minute after your temperature gauge begins to register, and then drive moderately until full operating temperature is reached.

These actions will provide the longest and most satisfying maturity for your vehicle


This article does not contain much in the way of numbers, nor graphs. It doesnÕt even state the sources for the ideas I tried across 40 years. IÕm not able to provide comparative engine measurements (I only have the "Good" ones), but I will share with you that I went to the engineers at the BMW automobile and motorcycle factories, and to their Le Mans Prototype racing team. I showed them the Mechanical Factors in the article and asked:

"What is false in these statements?"

"What is wrong in the recommendations?"

"What do you disagree with?"

There was only one disagreement with my statements: Following BMWÕs short statement of actions to follow during "Break-In" yielded the range of life span to the motorcycles that was a manifest fact (and in itself, highly laudable). But, they agreed that longer life spans would PROBABLY result if the stated recommendations were followed.

This ALSO included my recommendations about Warm-Up. BMWÕs manual paints a picture of a motorcycle idling away to the point of CATCHING FIRE. I doubt ANYBODY would warm up a motorcycle THAT long. In fact, MY recommendation was to warm the vehicle before riding only to the point of the temperature gauge beginning to register (probably about 120F to 150F degrees). If your BMW catches fire at THAT temperature, your problems are far beyond your warm-up technique.

Trying to justify my opinions, I suggested to the engineers that greater Smoothness of operation should result. That was met with, "YouÕll never be able to prove that."

"The Facts" of my article, or "Mechanical Factors" as I referred to them earlier, really do take place, and (I hope) as described in the article, are understandable things to most readers. ThatÕs really how it works, and the engineers agree. "How hard" and "how smooth" the delivered parts are determines how much of them are going on. But they do go on, and as described.

A reader has taken particular issue with "high throttle openings at low RPM" stating they could be damaging. I agree. I believe his issue stems from my reference in the article to "high" throttle settings when accelerating to "The Current RPM limit".

I wrestled for a means to describe what I meant by "high", and couldnÕt find an accurate "numerical" magnitude I could express. I ended up contrasting it to "simply rolling on the throttle" hoping the reader would see THAT as kind of "prissy and without authority". Also, there is a specific recommendation in the article AGAINST "High Throttle Openings". What weÕre after is to "Produce a NOTICABLE load on the engine, that will distinctly INCREASE the internal cylinder pressure." Please note the increase in pressure on parts ATTAINABLE by ANY throttle opening pales in comparison with the FORCE achievable, the SQUARE, with a velocity increase.

In the end, I failed to express that clearly, and the reader was right to object. I "know" how far to open the throttle, and can show you. I just canÕt express it in words yet. I apologize.

The REAL genesis for the offered recommendations comes from Pratt & Whitney and Rolls Royce. I dealt with factory reps from both since I grew up on an airport that housed an aircraft engine overhaul facility for both engine types. Both used chromed bores and rings, common to earlier BMW motorcycles. This is how these engines are STILL run in on an engine stand, and then in the aircraft. Remember these folks are at HUGE liability should their engines fail.

The follow-on, the CONTINUATION of my opinions stems from attending an engine assembly class conducted by a NASCAR engine supplier (who must remain unnamed) who uses, letÕs say, very similar part coatings and surface treatments to those used in BMW motorcycles.

© 2000 Richard D. Frantz, reprinted with permission.