Got a non series M521 Octalink set up on an 2008 Rockhopper which i’ve not seen before. Googling suggests newer Octalink should be “self removing” whatever that is, and then there is a tool available anything from £11 up to a Shimano badged £40 jobby, which seems OTT.

Do i need a special tool to remove the cranks and BB? Removing the crank nut and rubber washer and i’m non the wiser.

Mine need a standard crank removal tool. eh bit that pushes onthe end of the spindle needs to be wide enough not to go down the hollow spindle – or use a couple of 5ps as they are the right size

top end versions* had self extracting crank bolts, lower did not. If you’ve got a square taper crank extractor you can bodge something together with a 5p piece if you’re careful otherwise proper extractor (or extractor bolts or take it down LBS)

*not 100% about this actually, I got 2 xt octa cranks but only 1 pr of extractor bolts

A standard puller disappears into the hole. The hole gets narrower but not soon enough for the puller. I drop a small socket (like 6mm-ish) into the hole and use a standard puller.

5p sounds like a good idea.

I tried the “5p method”. Result was a bent 5p. Buy the shimano adaptor that allows you to use a square taper extractor. SJS cycles sell them.

For the cranks
http://www.chainreactioncycles.com/Models.aspx?ModelID=4939
or
http://www.chainreactioncycles.com/Models.aspx?ModelID=34314

for the BB
http://www.chainreactioncycles.com/Models.aspx?ModelID=689
http://www.chainreactioncycles.com/Models.aspx?ModelID=14914

Choices based on price only.

I used to use a rear mech pivot bolt in the hole which worked nicely – just get a toughened steel bolt to put in the axle hole (just big enough to fit into the crank recess) if you dont want to but the HTI tool?

Cheers all for the info.

I presume once removed the bottom bracket shell can take `standard’ XT BB cups and M770 crankset?

Yes your Standard BB shell will take these new fangled external cups, why heaven only knows:-)

Been impressed with Octalink although this particular bike has not been really ragged over 3 years.