I snapped mine being kack-handed and now the bolts keep loosening. What’s it called and where could I buy one?

It’s just there to hold the crank on if the bolts loosen, you don’t need it (unless the bolts loosen). None of my bikes have them fitted.

http://techdocs.shimano.com/techdocs/techdocs_search_results.jsp

should find it here and the part number
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FC/EV-FC-M583-K-2686_v1_m56577569830625626.pdf

the LX calls it a plate so enter your crank number and you should find it then google is your friend

Its just a marker to make sure the crank is on axle far enough. The small metal pin engages in the hole in the axle when the crank is on enough.
The crank shouldn’t fall off unless both bolts loosen and the end cap falls off.

http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FC/EV-FC-M583-K-2686_v1_m56577569830625626.pdf

in which case
Y-1FU 98120

http://www.ukbikestore.co.uk/product/118/1fu_9812/shimano-fc-m580-m660-security-plate.html

no idea how interchangeable but that is the same as the LX listed above

Thanks chaps 🙂

There is one on eBay http://www.ebay.co.uk/itm/SHIMANO-HOLLOWTECH-II-CHAINSET-SECURITY-PLATE-NEW-DH-TRIAL-XT-SLX-LX-DEORE-/200777986092

On eBay for twice the price I’ve seen in two different online shops 🙂

😳

Thanks chaps

FFS I did all the work and thanks everyone 👿
at least it is cheap eh…just like you etc
For clarity I am just joking, happy to help

And a big, extra-special man-cuddle to Junkyard.

one thing

you do know it has no bearing on the cranks loosening ?

if your cranks are coming loose then bigger powers are at work !

It’s just there to hold the crank on if the bolts loosen

I thought this but was correct by a LBS tech who said they were for setting the correct pre-load tension.

Having said that, they tightened the pre-load bolt far beyond the recommended torque.

Thanks 8)

Hold on, there’s no free postage option for that item 😉

No one likes a show off
Chapeau 😀

I think it was an atempt by the big S to overcome poor D.I.Y installation.

Either way it isnt needed if you can tighten two set screws. Tighten to correct torque and dont worry about it.

Seen those silly plastic things they put on the caliper mounting bolts? You dont need them either, Just mechanical sympathy and a good set of allen keys.