For most people, running in a new bike is a terrible frustration.  There they are, on their brand new shiny bike, (and, by the very nature of it being new, usually faster than their last bike), but instead of being able to open it up and revel in the power,  they have to run it in.  And, because they've just spent a lot of money, they really want to do this properly.

Now, an awful lot of crap is talked about running in.  Most attitudes and opinions about it were formed decades ago, when materials were poor, oil was worse, and engineering less sophisticated.  Many people say things like "I'm running it in carefully, I don't want to risk blowing it up".  Well (and this is never likely to be demonstrated, but all the same) I reckon it would be just about impossible to blow up a bike by not running it in.  I offer as justification for this the following :

• materials technology has come a long way in the past 20~30 years 
• modern oils have travelled a similar distance 
• modern production engineering tolerances have got much closer 
• ever heard of anyone running in a car?

If you have a bike which is an old design (say a Harley, or Moto Guzzi), then you probably should run it in carefully (they used to say that a Harley wasn't properly run in until it had 5000 miles on it, which just goes to show how crap their manufacturing is, in my opinion).  On a modern engine, however, the old rules no longer apply.

So, here is the Champ Top Ten Rules to a happy running in period.

1. Always make sure the engine is warm.  Design tolerances are calculated when everything is at its operating temperature, and has expanded accordingly.  Putting load on an engine before everything is hot means you are running outside these tolerances.  This is a rule for the whole life of the bike, not just for the running in period.

2. Vary the revs.  It's tempting to sit at the manufacturers quoted rev limit, just to get the miles done.  This does more harm than good.  Ideally you should keep alternating between putting load on the engine (accelerating) and taking the load off (decelerating). In fact, shutting the throttle hard and making it overrun will suck oil up the bores. And keep going up and down the gear box too - remember, you are running that in as well. For this reason, city riding is ideal for running in.

3. Do treat it gently for the first 100 miles.  You have to scrub in the tyres too, remember.

4. After the first 100 miles, start to work it harder.  The whole point is to 'knock off' any high points on all the new shiny bits of metal in your engine - you need to load it to do this.  When the engine is good and warm (e.g. you've done 20 miles), let it rev progressively higher, but not initially on full throttle.  Remember, the stress on the engine is due to the size of the bangs in the combustion chamber, as well as how fast they happen.  Limit the size of these bangs by using less than full throttle.  An engine at 6000 revs and full throttle is probably under more load than one at 9000 revs on half throttle.

5. Gradually increase the way you load the engine as the miles rack up, so that by the end of the running in period, you are almost running full throttle at max revs.  Of course, on a full on sports bike, the opportunities to do this on the road are limited, and may not happen that often during the rest of the bike's life.  Conversely, a 125 may be run flat out every day on the way to work.

6. Pay attention to how the engine feels.  Some people say that they can tell when an engine feels "tight", and treat it accordingly.  (Personally, I'm not sure I really believe this, especially if it's on a type of engine you've never ridden before).

7. Don't molly coddle the engine.  If you run it in too careful, the bores in the cylinder can get 'glazed' - they are too smooth, and the oil doesn't stick to them - instead it slides straight past the rings and out the exhaust, meaning that your engine burns oil.  The cure? Remove the barrels and rough them up with emery paper. This is expensive,  means your new bike has it's engine pulled to bits, and all because you were too careful.

8 Get it over with.  Most manufacturers still quote a 1000 mile running in period.  I reckon 500 miles is more than enough.

9. Do not delay the first service.  After running in, your oil will be full of all the tiny bits of metal that have been worn off.  The first service will probably be the most important that you have.  And it's usually free too.

10. Now go and give it a damn good thrashing.

(Disclaimer : if your engine *does* blow up, it's definitely not my fault, ok?)