When PD-M540 pedal bearings wear out, can you replace with XT or XTR parts? Better?

[morkys]

Just like the subject line says. Wondering if the XT or XTR bearings are better than the M540 so when your 540 bearings wear out, can you "upgrade" to the better bearings?

[SimpleJon]

Get from a bearing supplier that's all Shimano do - I usually just buy bags of 100 Gr10 SS bearings for the required bike sizes. Note the lower number of the grade of a bearing the better quality it is. Gr 10 is more than adequate for stuff like pedals and wheel bearings.

[morkys]

The 540/770/970 all use a similar cartidge bearing or cartridge style. I don't think they are sealed but I can't recall. Anyhow. Thanks for the info re the grade of bearing. Wait, so lower number equals better or other way around.

[Slash5]

Yes but doesn't look any better/different.
http://techdocs.shimano.com/media/te...9830625590.pdf
Shows interchangeable between 540, 959, 970.

[SimpleJon]

Just overhauled my XT clipless pedals - not sure which model number and they are loose cup n cone bearings not cartridge type.

The lower the grade number the finer the manufacturing tolerances more spherical they are - i think they go from 1000 to 3 or something. the price starts ramping up quite drastically below grade 10, (all the bearings below 10 at our local shop are ceramic not steel). Grade 25 are OK for bikes too - I think that's what dura ace and campy spec in their hubs, the only reason I got grade 10 was because - the local supplier doesn't stock the Grade 25 ones I wanted. You can use either grade 440C stainless steel or chromed steel balls

[morkys]

Ok, thanks. I guess I'll remember for when the time comes.