Main bearings...Whats the verdict?

coastie, there is a lenthy topic on this and IMO you will never get a sraight answer from anyone.I used what i would call a pro engine builder who specializes in single cylinder motors and put *** rollers in as this is what he does with all the race motards that run bearings.

Hey Coops,

Have you experienced any problems with your ball bearings?

I remember an old motto - it if ain't broke don't fix it :wink:

New ball bearings are easy to fit, with some heat. Heat the cases and they should just nicely drop out. Reheat the cases and drop the new ones in with perhaps another reheat to make sure they're set OK. Then install your crank (but without smacking witha hammer, just push or press).

Ball bearings are decent solution and they are fine, in my opinion. But of course that is never a guarantee.....

And by the way, there will not be a verdict on here at least. I think the true solution is way beyond the resources most of us on this forum have available to us and it will ultimately lie with those that have the necessary R & D facilities.

All the best,
Simon

Coastie,

If it were me I'd simply go down to my bearing shop and ask for a pair of premium quality 6206 C3 (or even a C4) from the likes of SKF - they've always done me absolutely fine and they don't cost the earth either.

Or even the same as you have just taken out...

Hope this helps,
Simon

IF IT HAS ROLLERS PUT ROLLERS BACK IF IT HAS BALLS PUT BALSS BACK,THE MORE BALLS THE BETTER AS LOAD IS SPREAD OVER A GFREATR SURFACE AREA ,ALSO I WOULD THINK BALL TYPE BEARINGS ARE BETTER PURELY BECAUSE ALL JAPS USE THEM AND YOU DONT SUFFER THE CROWD EFFECT OF ROLLERS ALSO THERE MAYBE SOME MODS DONE TO YOURS THAT YOU DONT KNOW ABOUTTHIS MAY CAUSE PROBLEMS IF YOUY DONT FIT LIKE FOR LIKE ,THIS BIT SHOULD BE IN CAPS MAKE SURE YOU USE METAL CASED BEARINGS NOT NYLON (I MEAN THE BIT SEPERATING THE BALLS)AS NYLON ONES ARE WHAT APRILLIA USE AND FAIL ALL THE TIME I HAVE REPLACED THESE AND METAL ONES ARE A LITTLE MORE NOISEY BUT LAST FOR EVER (WELL A LOT LONGER THAN NYLON ONES),,, FEEL FREE TO IGNOR THIS IF YOU GET A BETTER SUGESTION AS I AM A LITTLE DRUNK ,BUT I DO HAVE 12 YEARS EXPERIENCE IN THE BIKE TRADE .......THE CHOICE IS YOURS!!!PS SORRY ABOUT THE CAPS EVERY WHERE

Coatie ,at the end of the day all i did was replace what I took out rollers with rollers the only thing that changed was the bearing manufacture for me and the fact that the crank was balanced more acurately than the factory would do it.