The Shiny New AM831 Group Buy (A) Thread!

[FlaMtnBkr]

Mine is shifting perfectly with Shimano 12 speed and a 51 cassette. This may just be your setup which I would say is a good thing as you just need to work it out.  The frame play...well that is definitely a bigger issue.

I also have Shimano 12 speed with a 10-51 cassette and I've tried everything. I described it probably in the last 10 or 12 pages if interested. The hanger is definitely out of the limits of Sram's current specs for a hanger. It's not a ton but as precise and temperamental as the B screw adjustment needs to be, it's enough to cause problems. Adding 2 links to the chain allows the derailleur to rotate back into the correct angle and b screw adjustment and shifting got a lot better. But in the high gears the chain is too long so the derailleur is in wrong position and doesn't provide enough tension.

I've also gone above and below each adjustment trying to find some combination of adjustments that will work but nothing does and it's always noisy and "searching". I can show how it's out of spec but it probably doesn't matter because your shifting is either good or it isn't. Not that I have a solution, but it might be worth keeping in mind if someone ever has shifting problems they can't figure out. Anyways...

[FlaMtnBkr]

JJJ,

What software are you using for those drawings?

[JJJ]

JJJ,

What software are you using for those drawings?

Just Inkscape, no CAD software

[FlaMtnBkr]

Been a while since I've messed with that. Can you make a drawing or 'part' that you can move in relation to others, similar to 3D CAD? If not, seems like each drawing would take a while? I think it's still on my PC and will have to look at it again...

[JJJ]

Been a while since I've messed with that. Can you make a drawing or 'part' that you can move in relation to others, similar to 3D CAD? If not, seems like each drawing would take a while? I think it's still on my PC and will have to look at it again...

It's 2D vector drawing software, so you can group shapes, duplicate them and move them around. The second drawing was very easy to make from the first.

[scourge]

This is my first Chinese frame. Has something like this occurred with a frame before? Did the manufacturer do anything about it?

[cybrsrce]

Yes, I guess you're unlucky there. My bearings don't move in and out of the eyelet... yet. But I do have some traces of rubbing from the screw head.

That was the reason for my inside washer, it wasn't making good contact with just the one under the head of the bolt and was making a clicking sound. (http://chinertown.com/index.php/topic,3445.msg31880.html#msg31880)

I've attached a potential fix, using a second ball bearing on the outside. It does need crafting a custom screw, though.

I like that idea.

[Gigelz]

i like the idea to activate paypal...

[JJJ]

That was the reason for my inside washer, it wasn't making good contact with just the one under the head of the bolt and was making a clicking sound. (http://chinertown.com/index.php/topic,3445.msg31880.html#msg31880)

Oh, I hadn't seen that properly: so you have a 1.5 mm washer on each shoulder of the screw. IMHO you should file off 2 mm from the end of the screw instead, so that the smaller shoulder contacts the inner race of the bearing, and then you need no washers, except maybe a thin one under the head of the screw to protect from rubbing. Otherwise you have the inner race resting on the thread instead of the intended cylindrical portion. And is that grease on the screw? I believe that's one reason why your screw tends to loosen - I'd degrease the screw and add thread lock.

[Snacks]

When speaking to Eddy about this I was told shorter screws didn't work for them to fix the flex and they had to fix the mould for the rear triangle to get rid of the flex

[JJJ]

When speaking to Eddy about this I was told shorter screws didn't work for them to fix the flex and they had to fix the mould for the rear triangle to get rid of the flex

Is Eddy a technician? I'd rather say a middleman who probably didn't fully understand the issue. Regarding cybrsrce's case, he first needs to have the screw shoulder contact the inner race metal on metal, and have the race seated properly on a cylinder. That will contribute to reducing the flex, for sure.

[Snacks]

Is Eddy a technician? I'd rather say a middleman who probably didn't fully understand the issue. Regarding cybrsrce's case, he first needs to have the screw shoulder contact the inner race metal on metal, and have the race seated properly on a cylinder. That will contribute to reducing the flex, for sure.

no he is definitely not but speaks on their behalf. he hasnt answered any of my questions without conferring with the engineers first or at least thats what im being told.

[cybrsrce]

Oh, I hadn't seen that properly: so you have a 1.5 mm washer on each shoulder of the screw. IMHO you should file off 2 mm from the end of the screw instead, so that the smaller shoulder contacts the inner race of the bearing, and then you need no washers, except maybe a thin one under the head of the screw to protect from rubbing. Otherwise you have the inner race resting on the thread instead of the intended cylindrical portion. And is that grease on the screw? I believe that's one reason why your screw tends to loosen - I'd degrease the screw and add thread lock.

That reminds me that I ordered a chamfering tool to clean it up after cutting or filing if it came to that.  Need to see where that is.  I'm not sure why the threads are shiny in my picture but they're dry and they don't come loose, little wins I guess.

[sips56]

Maybe this was covered, but did anyone find a US based source for the Derailer hanger and more importantly the nut the axle bolts into?

[FlaMtnBkr]

I don't know if it fits, but Cube brand bikes has some models with a derailleur hanger that looks the same. I don't know if it will definitely work or how hard it is to find, but would at least be something to search for. Also, the threaded part should come with the hanger and be part of a set that sandwiches part of the frame in the middle and has a screw that holds everything in place.