I always believed in doing soft engine break-in's with little bursts of higher RPM's (hard break-in) for just seconds at a time. I've done that with my cars and bikes and haven't had any problems. No oil burning or anything awkward going on.
I think you'll find people who do "Hard break-in's" typically don't keep their bikes long enough to notice any problems with what they've done during the break-in period. Now if you ask the people who bought someones "Hard Broke in used bike" you'd probably see a bunch of unhappy customers.
Follow the instructions in the manual and you'll have a nice bike for your own use and something mechanically sound if you sell it.
This ol debate again. To me it just seems like a matter of preference. I've read that there aren't really an noticeable differences between the two. I'm a bit of a worrier so I tend to go soft at first and eventual start hitting it hard after some time has passed.
I do a lot of compression braking to seat the rings on the ride home from the dealer (~30 miles) with the engine up to 85% of red line. Oil change. More "ride it almost like you stole it" for another 100-150 miles with lots of engine braking and another oil change. More riding and a 3rd oil change at 600 miles.
Do the 600 mile maintenance (especially the valve clearance check) and ride the bike.
My 2009 CRF230L was broken in that way and has over 10,000 trouble-free miles. Admittedly, it is an older design, but that bike is used for trail riding and is worked harder than any normal pavement bike.
edit: I did have to weld the subframe back onto the frame, but that isn't a break in issue, I have used the bike rather vigorously. ;-)
Hard break in. I don't run it at redline and I do vary the speed at first. Other than that I ride it like I stole it. No babying on my part and thus I have never encountered bike issues due to mamby pandy break-ins
I've seen a lot do soft break in but i have always driven it with high spirits from the beginning but not like an idiot. The most crucial part i find is the first oil change. I find usually with new bikes you will find more metals and composites from the first oil change but after that is out of the way. Its smooth sailing.
I highly recommend a hard break-in.
This is what I always do with a bike ( new or rebuilt )
A gentle warm up for that very first drive.
The first 20 miles are the most important ones. After those 20 miles the rings won't be seating anymore. ( If they, do they would not make it to the first service if they wear down quickly)
So warm up , and then ride it like u stole it. Use the full rev range in as many gears as possible.
A race track is perfect for this, lots of braking and accelerating.
After that first drive, change oil + filter while its still hot.
Then use normally, the break-in is done for the piston-rings.
I have done this to many 2-stroke bikes and to a good deal of 4-stroke bikes.
The results are always good, good power and no oil consumption.
I can understand why the factory want everyone to take it very gentle the first 1000 km's, but the chances are u will be breeding a oil-consuming, gutless bike.
edit: I have alot of respect for those who do break in their bike softly, I cannot imagine not going over 5000/6000 rpm for hundreds of km's. I can see the people then asking "how's the new bike?" -"I don't know , I haven't gone above 4k rpm and 3d gear yet...."
I always run engines in the same way, put a tip-ex mark at 1/4 throttle and use up to that for the first hundred miles then put a mark at 1/3 rd then 1/2 and by that time they are usually run in, never had any mechanical problems and they all perform as they should,
never make the engine labour, let it spin, a nice twisty up n down road is ideal with lots of speed changes and engine braking down the hills, may sound boring but you will end with a better smoother and more powerful engine.
Hard break in is fine it your not keeping it and I suspect it's why some seem to have oil burning on engines were no one else as I have seen microscopic pics of engines broken both ways as a test and the hard ones looked as though the metal had been smeared rather than polished.
Ask 10 riders for there advice on this and you will get 10 different answers.
I've said this 100 times before and I'll say it again. I have built hundreds of engines for bikes sleds and ATVs. Both race and street engines and I have never in my life "broken in" an engine with the exception of breaking in a new cam for 20 mins and have never had a failure. I have seen proof of making less power by "breaking in" an engine vs beating on it.
Easy break-in. All the important hard parts haven't lapped themselves in yet on a new engine.
Pistons and rings need to wear-in, valves need to seat-in, bearings need to run-in, and transmission gears and bearings need to lap-in.
No wear patterns are established on a brand new engine.
Not a good idea to hammer on a fresh engine.
Only exception is a competition race motor that gets fully blueprinted during assembly, and tuned on a dyno.
Those engines get swapped out and rebuilt constantly. They are not built for longevity. So you can't really do an "easy" break-in on them.
Easy or hard break-in, the engine will live or it won't.
You can run a new engine hard right out of the gate, and it will probably be fine.
If all the clearances are good, and assembly was done properly.
I prefer to do an easy break-in. I don't want to hammer the parts until I feel they have some kind of an established wear-pattern on them.
Plus, it gives me a chance to listen to the engine awhile, and watch for oil/coolant leaks along the way.
No reason to baby it until the first service. I'd say do 200-300 miles easy. Then start progressively working it harder as you approach the first service interval.
Do the first service, including the valve adjustment, then you should be okay to let her rip!
I'm at 240 miles on mine, and I still haven't given it full throttle, or any high RPM's.
I keep the RPM's under 6k.
When it gets over 300 miles, I will run it a little harder.