breaking it in

[TM]

To me it's pretty obvious why the manufactures don't recommend a break-in like Motomans. They don't want to get sued by people involved in accidents with their products (expensive, both in money & reputation), better safe than sorry. I think the break-in is more for the driver (need to learn the new bike/model), than the actual vehicle. And a chance for the manufacturer to correct defects/errors originating from the assembly at the first service (oil, filter, check nuts & bolts).
Still, I see no argument against Motomans specific statements? :roll:

PokenH00D: "Most of his stuff just makes so much sense when you look at it from a practical/commonsense view" I certainly agree

TM, I find it difficult to believe any motorcycle (or car) company is worried about law suits resulting from a recommended break-in procedure that says there are no set rpm limits, particularly to the point that they are willing to ensure their motorcycles will suffer from reduced reliability and performance.

Motoman says;

“The honed crosshatch pattern in the cylinder bore acts like a file to allow the rings to wear. The rings quickly wear down the "peaks" of this roughness, regardless of how hard the engine is run. There's a very small window of opportunity to get the rings to seal really well ... the first 20 miles !! If the rings aren't forced against the walls soon enough, they'll use up the roughness before they fully seat. Once that happens there is no solution but to re hone the cylinders, install new rings and start over again.”

I don’t see the logic in these claims. If I am filing a surface smooth, it doesn’t matter whether I operate the file fast or slow or with high force or low force. It just affects how long it will take. A file doesn’t mysteriously wear out prematurely if you don’t use it fast or hard enough. How can the honed surfaces lose all their roughness without having done the same amount of work on the rings, simply because it was done slower?

Now let’s suppose for a minute that Motoman was correct about this running in with maximum force on the rings concept. Cylinder pressure is not proportional to engine speed, but torque. Max torque on the S3 is at only 5100 rpm and about 80% of maximum torque is available at 4000rpm, i.e. right around the recommended running-in rpms. Gee, maybe Triumph might know something about engines afterall...

[gr8shandini]

The thing you have to remember is that owner's manuals are written for complete idiots who are, unfortunately, still allowed to purchase motorcyles. It's far easer to say "stay under xxxx RPM until xxx miles" then to give the OK to occasional full throttle romps to redline, limited amounts of time at high revs, and the remainder at the more sedate portions of the spectrum.

[crudmop]

1 other thing to consider:

Most manufacturers follow a similar breakin procedure - mileage might vary, time might vary, but they are all similar. If following a manufacturer break-in procedure was horrible, causing premature ring wear, blockback, oil burning, or whatever, then it would suggest that ALL bikes following this procedure could conceivably been broken in wrong, and ALL bikes, or a good number of them, would have engine issues early on that would require serious repair. This would cost the manufacturer MILLIONS in warranty claims, etc, if you take a fair percentage of those which demonstrated problems while under warranty. Would the manufacturer suggest a breakin procedure which would all but guarantee them having to spend millions fixing the problems they caused?

Motoman makes some interesting points - but until that guy tells you that he will replace your motor for free if it goes south, I'd take his suggestions with a grain of salt.

[Diego]

> The thing you have to remember is that owner's manuals are written for complete idiots .... It's far easer to say "stay under xxxx RPM until xxx miles" then to give the OK to occasional full throttle romps to redline, limited amounts of time at high revs, and the remainder at the more sedate portions of the spectrum.

:???: Doesn't seem any easier to me.

Actually, Triumph is pretty clear about no full throttle "romps" with the break in oil. Knowing that there are idiots who will do it anyway, it would literally be easiest for them to say nothing at all about break in and just hope for the best. Ease isn't the issue. Optimizing the trade-offs between ultimate performance, engine longevity, and minimal break in interval are what they concern themselves with, and rightly so, IMO.

[TM]

On 2005-06-23 07:35, Fangit wrote:
[snip]
How can the honed surfaces lose all their roughness without having done the same amount of work on the rings, simply because it was done slower?

"How Do Rings Seal Against Tremendous Combustion Pressure ??
From the actual gas pressure itself !! It passes over the top of the ring, and gets behind it to force it outward against the cylinder wall. The problem is that new rings are far from perfect and they must be worn in quite a bit in order to completely seal all the way around the bore. If the gas pressure is strong enough during the engine's first miles of operation (open that throttle !!!), then the entire ring will wear into the cylinder surface, to seal the combustion pressure as well as possible."

Now let’s suppose for a minute that Motoman was correct about this running in with maximum force on the rings concept. Cylinder pressure is not proportional to engine speed, but torque. Max torque on the S3 is at only 5100 rpm and about 80% of maximum torque is available at 4000rpm, i.e. right around the recommended running-in rpms. Gee, maybe Triumph might know something about engines afterall...

So, where have I stated that the Triumph-manual was wrong? I only suggested reading MotoMans article about break-in and make your own conclusion.