Worn out M900 cassette

[Benandemu]

Sounds strange, but I've got a really good one that's missing half a dozen of its little screws. It came as a package of two M900 cassettes ages ago, but it was too good to kill, and I actually do need it now.
The thought of modifying some other screws doesn't really turn me on at the moment (the ones that Shimano used are a particular pitch, length, material, and angle), so I'm opting for the lazy route first.

Can anyone help please?

 

[FluffyChicken]

Re:

SPD plate screws are the same. Iirc they are a standard machine screw when I went looking
M4?, just need to find the flatter recessed heads.

The hard part is fixing the rear recessed chainring bolt thing.

 

[ishaw]

I've got one with the same issue. Spd bolts are too big if memory serves. How many screws do you need as happy to send it on if there are enough for you.

 

[Benandemu]

I'll have a look in the morning and report back on its exact status.
Thanks gents.

 

[Benandemu]

Well, I should have dismantled it before posting this up really.
Why somebody has taken it apart in the past is difficult to understand, but they've managed to snap the heads off 8 of the little screws. It wasn't clear to see this when the cassette was built. I've removed 8 other screws successfully, and these can be used again with a dab of threadlock. The rings are fine, but the carrier is probably beyond saving as it would be a horror to remove those 8 little studs buried in their captive threads.
So, I can either take yours and make one good cassette, or potentially you could now take mine and make one. I need an M900 cassette either way and still don't want to kill this one as I'm hopeful someone can make something from the bits of this.

 

[FluffyChicken]

Re:

I think I have 3 of these from BitD which are on my scrounge and repair parts list, the threadlock should be loosened with propanone/acetone to make it easier to undo.

They where often attempted to be removed as the top ring/rings came loose and also sometimes the lower rings would. So the only way to get to them is take off the rest.
I gave up after it kept happening with mine and went to M737s as I also gained 11T setups.

32 or 28 top?

 

[one-eyed_jim]

It's too late for your cassette now, but for future reference, these cassettes are assembled using a strong threadlock that softens substantially with heat. Heat also expands the aluminium spider. Plunge the whole thing into very hot water for a minute or so, and the bolts come out quite easily. Twist them too hard without softening the threadlock and the heads tend to shear off.

I've got a set of these bolts somewhere, but there's no guarantee I could find them this year.

 

[Benandemu]

It's a 32 tooth type P cassette.
The carrier is dead, but I'm hopeful that the rings could live again on a worn out cassette, by swapping over the rings.