Local bike shops can generally readily provide high volume MTB parts ex stock but a lot of the low volume items are not stocked and are better purchased on line.

Below are some of the suppliers I have found useful for sourcing some of those more obsure parts such as frame bearings or just general parts such as fork and rear shock maintenance kits plus a few others I haven't used as noted in the comments.

If you have a reasonable level of experience on the tools, most of these tasks can be readily undertaken - particularly with the ready access we now have to video demonstrations on YouTube. If you're not so handy with the tools, head on down to the local bike shop and see what they can do.

I have no commercial affiliations with the suppliers below.

Australian Supplier Links - Click On Images To Access

I haven't used this shop but they have a reasonable amount of MTB oriented stock. Online shopping available. Click on image

Traditionally a road bike shop, Cecil Walker has a good range of MTB components particularly for drivetrain components. Online shopping available.

DIY MTB has a good range of bearings, fork and rear shock seals and fluids. Online shopping available.

My local bike shop in Caulfield. Always helpful and can order stock in as required. Online shopping available.

USe ths shop as my go to shop. Great range and prompt delivery typically. Online shopping available.

Pushys have a large variety of bikes and parts including suspension seals, brake parts, etc. Online shopping available.

Great bike shop out in the back streets of Fitzroy oriented mainly towards mountain and cyclocross bikes. Grabbed a frame from these guys and price was the equivalent of the USA price which saved me carting one home. Can build up bikes or supply kits of components if you want to have a go yourself.

TBSM has a good range of bike parts and fork and rear shock servicing. Online shopping available.

TFM has a good range of bike parts. Online shopping available.

Jump on the mailing list to get some great bargains on tyres, tools, clothing, etc with free shipping offers from Velogear. These are regularly updated and some good bargains come past. Online shopping available.

International Supplier Links - Click On Images To Access

Wide range of items. Online shopping available.

Wide range of items. Online shopping available.

Good place to get frame pivot and other bearings. Online shopping available.