The Shiny New AM831 Group Buy (A) Thread!

[xtinction]

I was trying to reply to a post but managed to not get it quoted. He was suggesting that they had made changes to the layup of the carbon to make it stiffer, before this new triangle was designed. I was just trying to say that even if it was stiffer, if nothing was done like the double bearings, there would still be a design flaw. It wasn't about the new triangle. Sorry if that was confusing and I'll try to edit in the missing quote.

No worries man . I was just a little confused hahahah . thanks for your clarification

[FlaMtnBkr]

I'm trying to stay positive but that's pretty hard at this point.

Has anyone asked about a refund? Just about ready to walk away from all this...

[Stef Biggel]

If the bearings are still pressed in from the inside with no way to retain them,, and there are 2 bolts, one on each side, then there is still a design flaw even if lateral flex is reduced.

....

I think in the through-hole axis construction with two bearing each side it will be possible to put a thin barrel spaccer between link and first triangle bearing. In this case Link, Axis and inner part of the bearing moving simulary and there shouldn't be any rubbing on the frame.   

[cybrsrce]

If the bearings are still pressed in from the inside with no way to retain them,, and there are 2 bolts, one on each side, then there is still a design flaw even if lateral flex is reduced.

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. 

It doesn't seem like as many people are having shifting problems, but the derailleur hanger is built outside of Sram's 12 speed design specs. For some it may shift ok now, but I have to think it could be better if within specs. And what will happen once things start to wear? I don't know, but I do know mine doesn't shift worth a....hoot, and no combination of adjustments will make it any better.

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 gave the frame a chance and would love it if it worked as intended, but I will not be spending any more money on it when I still don't know if I will have a rideable bike.

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.

[xtinction]

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.

Thank you for taking the leap of faith my brother. I've been so worried about ruining the frame with riding it ( heavy rider here) that ive been putting off building my bike so it will be great to see if the fix really solve the issue.

[deucelee]

Heidei really needs to look at some successful examples of business crisis management.  What they're doing is NOT a good example.  At the very minimium, they should sponsor JJJ's fix for us AND offer the new triangle at half off.  What would be ideal and even better is if the new triangle is sent out for free to those that are still under the 1yr warranty period.  Most of these chinese bike frames from aliexpress have a 2yr warranty anyway.

This forum are a dedicated group of buyers who are NOT afraid to try out chinese frames while their friends are all "oh hell no" to chinese frames.  That means this group of buyers will be the people that try to persuade their friends to buy frames such as this.  This is not good business crisis management.  I'm not blaming Eddy directly cus maybe he's just being a spokes person for the company.  Their director's and CEO's need to realize that if they want to keep the ball going for sales on the ground, they need to handle this much better.   

[Nekross32]

Actually this design flaw bite me in the ass, i broke my collarbone on a berm due to the flex, i usually rip those. Im not a heavy rider 85 kg fully kited. And i was charged the same price for a new rear triangle. I feel this is the worst way to handle this situation.

[deucelee]

Actually this design flaw bite me in the ass, i broke my collarbone on a berm due to the flex, i usually rip those. Im not a heavy rider 85 kg fully kited. And i was charged the same price for a new rear triangle. I feel this is the worst way to handle this situation.

Wow dude that sucks big time If they're in the US, they'd be getting sued for sure.  There's still time to right this ship but completely agree, this is a terrible way to do business crisis management. I hope they see your post and that opens their eyes on the dangers of their product as is.  I understand it's going to cost them a lot of $ but hey, folks could have spent their hard earned money elsewhere if they knew this kind of circus would happen.  Fix the issue correctly and have a brighter future or don't fix the issue correctly and it will be a example that will be used for years to come.

[cybrsrce]

Actually this design flaw bite me in the ass, i broke my collarbone on a berm due to the flex, i usually rip those. Im not a heavy rider 85 kg fully kited. And i was charged the same price for a new rear triangle. I feel this is the worst way to handle this situation.

Ooof, that sucks.  Can you tell us a some more about how it happened?  Just curious if you explain the sensation in a similar way.

What bike did you come from before the 831? 

[Nekross32]

My previous bikes are a Polygon Siskiu T8 and a Rocky Mountain Slayer.

I feel the rear is slipping and not following the path that i expected and sometimes i feel the rear tyre under load rubbing in the chainstay. Personally the frame feels nervous for me

[JJJ]

Finally we got the solution of the flexing of the frame FS-AM831.
The upgrated of the new mold of triangle, if you need it, contact us.

Eddy@haidelibicycle.com

We also found that JJJ have the idea of the bolts to solve the problem, really thanks for his help and effort.
But that's would not be our solution and cannot ensure it would be works.

Thanks for all the supporting and understanding.
Feel free to contact me via email.

All the new order would be use the new mold.

OK, I'm looking at the bottom link design now. Not fantastic, and the new through-axle "fix" is no better. Duh  I really don't understand why they didn't clone the SC links!! OK, maybe, the SC through axles are a little sophisticated with tapered expandable portions...

I need to come up with pictures to explain better. The problem is that the bearings are mounted into eyelets that will flex inward under axial forces. With V1, as the eyelets flex, the bearings are slightly pulled out of their recesses by the bolts. The issue is not dramatic if the clearance between the bearings and the triangle walls is near zero or even negative, meaning you insert the link between the triangle walls with some force. You then rely on the rigidity of the eyelets to keep the clearance near zero under axial forces.

If there is clearance, it will be filled by the eyelet flex and shifting out the bearings upon tightening the bolts. As long as the press-fit force of the bearings remains, any axial play will be subject to a lot of resistance, which is alright.

With V2, there is nothing exerting axial force on the bearings to keep them against a wall. If there is clearance, the link will shift freely from one wall of the triangle to the other. It could be assumed that the clearance is eaten up by tightening the hell out of the through-bolt, causing the chainstays to flex against the link, but this is unlikely, given the very thick carbon in the area... So you better hope there is zero or slightly negative clearance in your case.
 

[Stef Biggel]

Hey JJJ, why you can‘t push the inner bearing in the pocket by puting a Spacer in the Gab between Link and Triangle. Than the Bearing can be pushed by the tension of the Axis?

[JJJ]

Hey JJJ, why you can‘t push the inner bearing in the pocket by puting a Spacer in the Gab between Link and Triangle. Than the Bearing can be pushed by the tension of the Axis?

The problem is that the clearance depends on manufacturing tolerances. Some will have zero, others will have more. So everyone would have to play around with a set of shims of varying thicknesses, whereas such issues can and should be fixed by design.

[Stef Biggel]

Sure! But fortunately if there is only a tolerance of up to 0,5mm it can be solved by torquing the Axis force more. There should be enough flexibility in the Triangle. This woun’t work in v1 because of the rubbing screw. In Your solution it should also work.

Yes may they should copy the SC Link. But maybe there is a reason why they don’t do we don’t know.

[JJJ]

OK, I'm looking at the bottom link design now. Not fantastic, and the new through-axle "fix" is no better. Duh  I really don't understand why they didn't clone the SC links!! OK, maybe, the SC through axles are a little sophisticated with tapered expandable portions...

This how SC do it. The pink bolt has an expandable head. It is screwed tight pinching the inner races of the bearings against the right carbon stay through the yellow spacer. The outer bearing races are held in opposition in the link. Then the orange tapered bolt is screwed into the pink bolt head, expanding the bolt head in the recess of the left carbon stay. No clearance remains, no matter what the distance was between the two carbon stays.

I need to come up with pictures to explain better. The problem is that the bearings are mounted into eyelets that will flex inward under axial forces. With V1, as the eyelets flex, the bearings are slightly pulled out of their recesses by the bolts. The issue is not dramatic if the clearance between the bearings and the triangle walls is near zero or even negative, meaning you insert the link between the triangle walls with some force. You then rely on the rigidity of the eyelets to keep the clearance near zero under axial forces.

If there is clearance, it will be filled by the eyelet flex and shifting out the bearings upon tightening the bolts. As long as the press-fit force of the bearings remains, any axial play will be subject to a lot of resistance, which is alright.

Here is the picture. There is a 1mm clearance that is filled on the left side by pushing the bearing out of its recess by tightening the bolt. The bearings will shift in and out of their recesses as the eyelets flex. In fact, the issue is similar to that of the upper link - the bolt heads might end up rubbing against the aluminum if the clearance is big.

With V2, there is nothing exerting axial force on the bearings to keep them against a wall. If there is clearance, the link will shift freely from one wall of the triangle to the other. It could be assumed that the clearance is eaten up by tightening the hell out of the through-bolt, causing the chainstays to flex against the link, but this is unlikely, given the very thick carbon in the area... So you better hope there is zero or slightly negative clearance in your case.

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.