OS55 rear bearing problem.

As some of you know my new OS 55 let go the other day during break in,the rear bearing was shot.
I've had confirmation that it's being replaced under warranty and they said the metal bearing retainer had come apart.
Doing a little search online I'm not the only one.See this thread.
http://www.helifreak.com/showthread.php?t=174607
I'm not sure what to do,whether to try a YS56 or to change the rear bearing to something else before break in.
Any thoughts?
Thanks.
Danny.

If the metal retainer is breaking up, that would point to one (or more) of these things being the cause:

Not enough lubrication.
Too much speed
Too much load.
Rubbish quality bearings.

The first three are design issues (provided you are operating the engine as per the destructions). The last one smacks of the accountants running the engineering department (don't get me started!).

It's good that OS are replacing it under warranty, but I would be concerned about when it will let go again. If it is a couple of months into its life, would they replace it under warranty again?

Andy

Ceramic bearings may help a bit, but if the design issue is a lack (or too much) lubrication at certain operating conditions, they will still go pop sooner or later!

What would really help, is if we could see the broken bits. You can tell a LOT by inspecting things like worn bearings, broken bits of metal etc.....

Andy

To look at the balls were still in the cage but there was a couple of jagged edges on the outside of the cage and at first I didn't see that the retainer was missing untill they told me.
The conrod looked like someone had grabbed it with long nose pliers and the backplate had scratches where the conrod had been spinning.
It sounded mega rough from the first startup.
I wonder why they changed from the plastic retainer on the 50 to metal on the 55.
I'd like to try a YS 56 but it's not cheap at £225.
Dave have you tried Boca bearings before?Are they any good?
Thanks
Danny.

Wise words from Andy regarding reasons for failure. It does suggest to me lube failure AND cage failure.
At least it's being replaced free under warranty.

I hope that means they give you a new replacement engine FOC. So many of the other parts must also have been damaged by all the debris flying round, it is really beyond repair.

Whilst in warranty, if you dismantle it at all. you'r on your own. So if it's OK after the exchange you had a lucky escape.

Crimped pressed steel cages are a cheap, popular (and nasty) way of keeping your balls apart ! There are better methods for high speed applications like the nylon moulded spacer cage you mentioned.