Author Topic: The Shiny New AM831 Group Buy (A) Thread!  (Read 178307 times)

FlaMtnBkr

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1065 on: December 14, 2021, 12:36:31 PM »
There are better designs but I wouldn't consider it a flaw.  I ended up tapping the upper link and the bolts tighten without washers, that is a QA problem.  Do they stay tight? Yes.  Do I like that the carbon is a bushing? No.  I still ride it 2-3x per week as-is, excessive flex and all. 

Yours is, this is most likely a QA issue again.  Mine shifts super smooth but I also checked it while building and have had to straighten it twice.  I ordered a few extra with the frame and you can grab them from Ali, I wouldn't write it off until you replace it or straightened it if you haven't already.  I know, it is money you shouldn't have to spend and you can try to push Eddy to send you a new one.

I paid for the new triangle, I'll be the guinea pig.  If it makes the frame great then it is still a bargain at 1/3 the cost of a Hightower CC.  If not, I (we) gambled and lost.

I guess it depends on your definition of a flaw. Does bad design that introduces flex and frame wear sound better? From an engineering standpoint, it is a flawed design. I don't think you will find many other bikes where the frame and fastener is forced to act as a bearing/bushing as opposed to the actual bearing next to it. And that's just the one pivot.

I have made sure my hanger is straight and replaced it with one of 3 spares I ordered. But they are all the same so I didn't expect much and it did nothing to help. I provided the drawing from Sram and anyone is free to measure theirs to see if it's within spec, but it's not. Looking at the drawing, these hangers have a x=15 and an L=27mm. When 1mm of B screw adjustment can have a large impact on shifting performance, thats a big difference from what the hanger should be. And as Sram states at the bottom of the pic, anything outside of those dimensions can effect shifting performance. If others are OK with it out of spec that's their choice, but it shouldn't be. And a QA issue would be tenths or hundredths of a mm, so the hanger just has the wrong dimensions.

I thought I was buying a working frame and didn't see anything about gambling. It also took more than a year longer for it to be ready and I think most of us assumed they were sorting out these kinds of details. But I guess we all have different expectations when buying something. But could you imagine Santa Cruz releasing this frame to the public?

Stef Biggel

Re: AM831 bottom link design
« Reply #1066 on: December 14, 2021, 02:06:13 PM »

Here is the picture. Not sure if a clearance in the higher range of the tolerance (like on the left side) can be compensated by pulling the two stays together in that area. And by pulling together the stays with a smaller clearance, the eyelets will flex inward, breaking the parallelism between the bearings. Compensating a large clearance is not guaranteed, but there will be no bolt head rubbing as in v1.



I will measure when the frame is arrived, but there are shim washers A2 DIN988 from 0.1 to 1mm 15mm x 21mm … this should work.
« Last Edit: December 14, 2021, 02:12:15 PM by Stef Biggel »

zilcho

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1067 on: December 14, 2021, 03:22:06 PM »
I thought I was buying a working frame and didn't see anything about gambling. It also took more than a year longer for it to be ready and I think most of us assumed they were sorting out these kinds of details. But I guess we all have different expectations when buying something. But could you imagine Santa Cruz releasing this frame to the public?

Before the frames began to ship we knew about the issue with the fork crown hitting the downtube, already calling in to question the design quality. How is that not taking a gamble? If you haven't noticed, the entire world is behind on delivering products over the past two years, and frame manufacturers pushing back release dates is par for the course, even before covid. This direct to consumer business model is a side hustle for them with the majority of direct to consumer sales going through AliExpres/Baba, but still nothing compared to OEM sales for most of them. THEY AREN'T Santa Cruz! That's why this frame cost you less than $1,000! The quality of the product is debatable (outside of this frame), but you are not going to get the same customer service as a Western brand that values is reputation.

This forum has a few thousand registered accounts and who knows how many are actually active or have bought any frame recently. Compare that to that number of frames sold from all of the pop-up shops on Ali all selling the same frames and showing hundreds of units sold. To think you have some sort of position to make demands because of this forum and group buy is just asinine. With how much so of yall are posting now I would have assumed you did your due diligence about the process and expectations of buying a frame direct from China. You shouldn't have to settle for a defect but that was the risk in jumping in for the cheaper pricing with an untested frame, the first Chinese frame I'm aware to use VPP, from a vendor that wasn't considered to be in the top list to begin with.

I realize yall probably don't want to hear any of that but this thread has become a bunch of Karen's demanding the manager. Instead of crying "poor me, I paid money", why not use your collective numbers to go through the proper channels (payment providers) and try to get results. It's obvious Eddy doesn't read everything here, or even have much say in things, and it's crazy to think they're going to ship these for free worldwide without some pressure.

JJJ

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1068 on: December 14, 2021, 03:30:00 PM »
THEY AREN'T Santa Cruz! That's why this frame cost you less than $1,000! The quality of the product is debatable (outside of this frame), but you are not going to get the same customer service as a Western brand that values is reputation.

In summary, as some of us said here, we gambled and lost  ;D

cybrsrce

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1069 on: December 14, 2021, 03:30:45 PM »
I guess it depends on your definition of a flaw. Does bad design that introduces flex and frame wear sound better? From an engineering standpoint, it is a flawed design. I don't think you will find many other bikes where the frame and fastener is forced to act as a bearing/bushing as opposed to the actual bearing next to it. And that's just the one pivot.

See now, I have little to no chainstay movement and no frame rub.  With the bolts tight my seatstays roll and that is it.  Net result is that the rear tire is super unpredictable in flat turns and berms.  Carbon layup shortcoming for a force that isn't tested is what I believe is my frame problem.  Yeah, bolt on carbon is not optimal but I don't think it will cause a destructive event, I could be wrong.  I concede that you are right, it is a flaw - we just have differing degrees of it.

Quote
I have made sure my hanger is straight and replaced it with one of 3 spares I ordered. But they are all the same so I didn't expect much and it did nothing to help. I provided the drawing from Sram and anyone is free to measure theirs to see if it's within spec, but it's not. Looking at the drawing, these hangers have a x=15 and an L=27mm. When 1mm of B screw adjustment can have a large impact on shifting performance, thats a big difference from what the hanger should be. And as Sram states at the bottom of the pic, anything outside of those dimensions can effect shifting performance. If others are OK with it out of spec that's their choice, but it shouldn't be. And a QA issue would be tenths or hundredths of a mm, so the hanger just has the wrong dimensions.

I'll have to measure mine, I never though to check those dimensions since it setup in minutes and I've only had to straighten it from me bashing into things.  Direct from China QA is stamping them out, giving it an eyeball, and throwing it into a good pile or bad pile so I wouldn't be surprised if they're all just like yours.  We made enough noise for the triangle to be redesigned, we can get support together for this as well.

Quote
I thought I was buying a working frame and didn't see anything about gambling. It also took more than a year longer for it to be ready and I think most of us assumed they were sorting out these kinds of details. But I guess we all have different expectations when buying something. But could you imagine Santa Cruz releasing this frame to the public?

Unfortunately all of the frames talked about on this site are a gamble.  This one more so because it is an unfamiliar design unless the mold maker is the OEM for Santa Cruz.  If so shame on them, they have all the IP - steal better... (j/k)  The difference between these frames and the ones coming out of the same factories headed to Santa Cruz is that they have their own QA/QC onsite making sure only the best units get shipped.

Don't get me wrong here, I am on your side - the upgraded triangle should be a nominal fee to cover paint and shipping for as many revisions as it takes to get it to a universally accepted level.  This is the first frame with issues of the many I've built from various direct vendors and I'm not excited about it, I just except that I roll the dice every time I buy one.

JJJ

Re: AM831 bottom link design
« Reply #1070 on: December 14, 2021, 03:40:02 PM »
I will measure when the frame is arrived, but there are shim washers A2 DIN988 from 0.1 to 1mm 15mm x 21mm … this should work.

There is still another issue with this through-axle design. You can't put a spacer between the inner races of the bearings that can take the pressure of the bolt (unless you take out a bearing to slip in the spacer), so there is a great uncertainty on how tight you can torque the bolt. You can go as far as the flex of the stays and then the eyelets permits. If the stays do flex a bit and there is zero clearance (or you have filled the clearance with shims), you're going to start flexing the eyelets and ruin the bearings.
« Last Edit: December 14, 2021, 03:44:29 PM by JJJ »

cybrsrce

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1071 on: December 14, 2021, 03:52:10 PM »
Before the frames began to ship we knew about the issue with the fork crown hitting the downtube, already calling in to question the design quality. How is that not taking a gamble? If you haven't noticed, the entire world is behind on delivering products over the past two years, and frame manufacturers pushing back release dates is par for the course, even before covid. This direct to consumer business model is a side hustle for them with the majority of direct to consumer sales going through AliExpres/Baba, but still nothing compared to OEM sales for most of them. THEY AREN'T Santa Cruz! That's why this frame cost you less than $1,000! The quality of the product is debatable (outside of this frame), but you are not going to get the same customer service as a Western brand that values is reputation.

This forum has a few thousand registered accounts and who knows how many are actually active or have bought any frame recently. Compare that to that number of frames sold from all of the pop-up shops on Ali all selling the same frames and showing hundreds of units sold. To think you have some sort of position to make demands because of this forum and group buy is just asinine. With how much so of yall are posting now I would have assumed you did your due diligence about the process and expectations of buying a frame direct from China. You shouldn't have to settle for a defect but that was the risk in jumping in for the cheaper pricing with an untested frame, the first Chinese frame I'm aware to use VPP, from a vendor that wasn't considered to be in the top list to begin with.

I realize yall probably don't want to hear any of that but this thread has become a bunch of Karen's demanding the manager. Instead of crying "poor me, I paid money", why not use your collective numbers to go through the proper channels (payment providers) and try to get results. It's obvious Eddy doesn't read everything here, or even have much say in things, and it's crazy to think they're going to ship these for free worldwide without some pressure.

"SB130 frame is $4k?  It isn't even available in Yeti turquoise."
Over to chinertown.com:
"What is that?!  Kinda looks like a Santa Cruz, that is really nice!  How much?  {throws money at Eddy}"

That was my process for this frame, I didn't even Do My OwN rEsEaRcH!?!?!  I am doubling down though (quartering?) and sticking with it!

Stef Biggel

Re: AM831 bottom link design
« Reply #1072 on: December 14, 2021, 10:58:15 PM »
There is still another issue with this through-axle design. You can't put a spacer between the inner races of the bearings that can take the pressure of the bolt (unless you take out a bearing to slip in the spacer), so there is a great uncertainty on how tight you can torque the bolt. You can go as far as the flex of the stays and then the eyelets permits. If the stays do flex a bit and there is zero clearance (or you have filled the clearance with shims), you're going to start flexing the eyelets and ruin the bearings.

Yes JJJ, you are right. In this construction it is not possible to give force over the axis without damage the outer bearings. It must be filled by spacers very correctly. This is the big disadvantage to bearings in the link.

JJJ

Re: AM831 bottom link design
« Reply #1073 on: December 15, 2021, 02:00:57 AM »
Yes JJJ, you are right. In this construction it is not possible to give force over the axis without damage the outer bearings. It must be filled by spacers very correctly. This is the big disadvantage to bearings in the link.

Unless they provide a spacer to go between the bearings, that you would have to slip in by removing one bearing, I would not trust this through-axle design!

Stef Biggel

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1074 on: December 15, 2021, 02:14:06 AM »
Yes, i see. I'm nearly sure we have to remove one bearing in the new contruction and fill in a spacer. I will write it to eddy but not beeing to optimistic that it changes anything.

Stef Biggel

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1075 on: December 15, 2021, 06:38:56 AM »
I'd written Eddy my idea to eliminate the play between Link and triangle (see my atteched PDF). Maybe it will be worth for something.
« Last Edit: December 15, 2021, 06:41:56 AM by Stef Biggel »

JJJ

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1076 on: December 15, 2021, 06:45:36 AM »
I'd written Eddy my idea to eliminate the play between Link and triangle (see my atteched PDF). Maybe it will be worth for something.

That seems to be the upper link, which should be alright now with the two bearings in the triangle eyelet. The previous discussions were about the new lower link through-axle design. However you point out that there should be a spacer between the two bearings, or some other means to not crush them when tightening the bolt.
« Last Edit: December 15, 2021, 06:49:30 AM by JJJ »

darius72

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1077 on: December 15, 2021, 07:22:49 AM »
I've just sent the 10 eur to JJJ for the bolts; the solution is a patch over but mechanically is brilliant, it should be fine. The Haideli solution is expensive and to me looks not ideal; as stated before the Santa cruz scheme is ideal, I also don't understand why they didn't copy it, normally the chinese are very good in copying.
Concerning the lower link it could be affected by the same problem in theory, but after locking the upper one with the new bolts I think the chances that lateral forces could move the bearings are minimal; what do you think JJJ?
Thanks again for the precious work

Stef Biggel

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1078 on: December 15, 2021, 07:30:57 AM »
That seems to be the upper link, which should be alright now with the two bearings in the triangle eyelet. The previous discussions were about the new lower link through-axle design. However you point out that there should be a spacer between the two bearings, or some other means to not crush them when tightening the bolt.

You're right, this is the upper Link. I thinking about, also use a Axel on this, like SC do.


JJJ

Re: The Shiny New AM831 Group Buy (A) Thread!
« Reply #1079 on: December 15, 2021, 07:46:55 AM »
Concerning the lower link it could be affected by the same problem in theory, but after locking the upper one with the new bolts I think the chances that lateral forces could move the bearings are minimal; what do you think JJJ?

I don't like that lower link, but I prefer V1 to V2. The lower link V1 is not as bad as the upper link, because the bearings are rigidly coupled to each other in aluminum, and the carbon chain stays are in a region where they will not flex much relative to each other, guaranteeing a substantially constant width in the link area, i.e. the flex won't tend to pull out the bearings from their recesses as much as in the upper link.