My Chain Tension Plate... BMW part number 33177650081... which BMW calls a "Supporting Plate" in the parts fiche... went belly-up on my last trip. As you can see from the pictures below, the innards pulled out.

The field repair was to simply take the broken-off piece and use it as a washer on the outside of the plate. It looked like hell, but it worked.

A new plate from BMW is about $11 online. $11 for what though? A poorly designed POS aluminum plate that breaks? I don't think so...

I got to looking at the TT version... Chain Tension Plates F650GS, Part Number: 051-1206... about $30 for two plates. These are made from steel and have a nice finish on them. There are also holes on the tabs so you can screw the chain tensioner to the swing arm; you'd have to drill the holes in the swing arm and find the appropriately sized bolts though... I chose not to do this yet.

Here are some pictures of the failed BMW one and the TT one...

It comes with two bolts to replace the stock bolts, but I like the Torx bolts, so I kept them.

Looks like this installed...

The only minor complaint I could come up with is where the tabs mount to the plate. You can see it in the imperfection in the first and last pictures, but it's really nothing.