FWIW, I also have a 1x ten speed with an 11-42 cassette with a Shimano Deore Shadow RD, although mine is labeled RD-M592. It was originally servicing an 11-36 cassette, which I replaced when I began riding in the mountains. Although Shimano rates the derailleur only for up to 36 teeth, I had zero problems adjusting it to accommodate the 11-42, and I didn't need or use a Wolf Tooth Link. I simply adjusted the B-screw and the indexing, and it's been excellent. I question whether you really need such a link when you install the new cassette. An unneeded link could add unneeded flex, but I'm not an expert. Full disclosure: my ride is an ICE recumbent trike, but it's a straight forward mtb cassette, derailleur and bar end shifter. Please report your installation results.

Don't know if the RD-M786 is supported by the GL. See below from WT's, from their website. Go to their site for full details & install instructions.

Yes, mounting with the original B-link puts the RD in a quite different position. Older style RDs did actuate differently in different parts of the 'extension range', don't know for sure if 'Shadow' RDs work the same.

Agree. Seems like the WT Goat Link was installed in 2018 and has worked until recently. Questioning the compatibility with the derailleur now seems like a red herring.

Replace the cassette, you dumb cheap bastard. 😉

I am, I am! fleabay shipping says est Tue 14th

thx for reporting, but that pic looks like you do have ONE extender, unless that connector with the elliptical dimple is part of the original RD?

From the original thread where I posted about buying this used bike, here's a photo of how the drivetrain looked as I received it



NOTE pre-goatlink in the back, smaller cassette, and double in the front

Not the clearest picture, but you can see 2 'knuckles' instead of the now 3

nvm, pictures online of my M786 show 2 knuckles OEM, I don't know if that's considered an extender already as part of the original design

No, not an extender, that is just the normal mount, what is called the B-link.

That is removed and replaced with the GL when trying to extend the range, (if the model is compatible). See the Wolf Tooth instructions.

hmmm I guess I didn't follow the wolf tooth instructions. I'm hesitant to fix what aint broke, but if the swapped in new cassette doesn't shift great, it's good to know I've got an option I can try

Found the instructions.

I think I will go ahead and remove the B-link -- I guess the WTGL is just that few mm longer as a replacement B-link that it makes a difference?

Yes, just a little longer and a change in the angle. The GL is rotated a little more downward than the standard B-link.

That's part of the original RD. I've never bought an extender. I replaced the derailleur hanger once, and it's the piece going from the dimpled doodad to the dropout.

I thought you were going to notice that my chain was incorrectly threaded from the top jockey wheel to the bottom one. I noticed it while looking at the picture last night. I could have sworn I did it correctly when I recently replaced the chain. My brain doesn't work so well, sometimes, so keep that in mind if you're tempted to follow my advice.

lol I'm sorry I did not notice that for you! But I'm glad that taking a pic to post here gave you the opportunity to get a closer look yourself!

Everything is sorted. The other thread helped me deal with the notched freehub when swapping the cassette, and I set the RD up with the goatlink replacing the b-link as intended, rather than extending. Also I got my front brake back from the shop -- trying to clean the pistons, I pushed a piston out too far, lost all the fluid, and was not skilled enough to recover.

So now I have a whole, well-running mountain bike agan: new chain, new cassette, rejiggered RD, two brakes which are smooth, quiet, effective, and feel equal in the two hands.

Went out with the wife for a great ride at Mt Laguna -- my favorite trails in San Diego: the lovely shaded gentle climb of Agua Dulce, the swooping banked downhill switchbacks of Gatos Ravine, and the gloriously flowy singletrack on the west side of the meadow loop. Only downside is it takes over an hour of driving to get there. If the job I'm angling for comes through and I move out of state, that may be the last time ever.

Was this ever answered?

no, the thread very quickly focused on

If you have any tips I'd love to hear them!

Nope! I am just as curious as to the answer as you probably are.

One thing I kind of taught myself is to look very closely at the chain while turning the crank slowly, watch to see if any of the links get grabbed by the next larger cog at all -- if so, dial the adjuster barrel to the right until that just barely stops happening

The answer was to consider wear.

As a general comment, derailleurs are designed for a certain cassette slope. So if you need a hanger extension to clear the low cog, you aren't changing the slant the derailleur works on, you're just lowering away from all the cogs. That's why the high gears (small cogs) can become harder to shift - you've moved the entire derailleur away from the small cogs. The only reason it works as all is due to the power of HG cogs.

"Believe it or not, this is after my wife kindly volunteered to wash my bike"

Forget all that chain wrap and B-screw crap. I want to know how to do this!

lol step one you have to have a wife who is even more into mountain biking (and better at it) than yourself. I have no idea how I got so lucky, so I can't help you there