The Shiny New AM831 Group Buy (A) Thread!

[Snacks]

So after you took them out you confirm that original bearings are cheap?To me they are too loose and they roll too easy being new. Do you rember the size, is it a standard SKF/other manufacturer size?
OEM BB has another problem: no lip to hammer it out, you can just hit the bearing, but if the bearing will come out it will be basically impossible to remove the cup from the frame I think.

They're actually not bad but since I had the bb out of the frame it was easier to work the bearings out. so I swapped them right away. They are standard 6806 bearings,  I believe.  I'm on a business trip but I can check when I get home.

[FlaMtnBkr]

I have had press fit BB but haven't had to mess with them, but it sure does seem tight. Though I guess it has to be. I don't see how it would be possible without a bearing press. I got a ZTTO thread together BB and it seemed slightly smaller diameter though I didn't measure, and has 2 o-rings on each side so a softer material helps tighten things up without being real tight. Since both sides thread together it acts like a press and stays held together so it doesn't need to be really tight.

At least from what I can tell messing with both, which makes me glad I got the threaded type.

I also got a 7120 crank which has to spacers and the instructions say for a PF92 BB to put one on each side. But this left the non drive arm with the axle only about half way in which didn't seem right not having the splines fully engage each other. So I removed the spacer on the drive side which made the non drive look correct so I'm not sure why it didn't need both unless the thread together BB is a bit wider than an actual PF BB? This placed the bolts on the chainring fairly close to the frame but a few mm clearance which seems about perfect for that crank. The teeth have a bit more clearance being 32 teeth and I would think I could go up 2 or 4 teeth without a problem.

I'm still deciding what I'm going to do for frame and paint protection but I got some materials today and will come up with something. I still need to double check my wheels dish and finish them up while bringing up to final tension. After that it should be done in a few hours. Though I do want to come up with a fender to protect the rear linkage and back of the shock. It's hard to see but some of the linkage bearings are very exposed.

Good luck and hopefully we start seeing some finished build pics and ride reports. I'm really tired so I apologize if this is wordy or hard to read. I type fast and not checking for mistakes right now...

[StefanB]

I'm going to use a threaded/press-fit, ceramic bearing from Zitto. I haven't tried these before so I can only hope the quality is ok.

[darius72]

Stefan, I see same color and same progress as me more or less  .
BB issue: I think the threaded BB is the way to go, maybe I will install the stock BB with no inner spacer, just to be sure that I could remove it later; ZTTO BB looks good but aliexpress transit time is approx 15 days : otherwise I see in german online shop token makes same threaded BB, just slightly more expensive.
Chainline issue: the difference between shimano XT 8100 and 8120 (or slx 7100 and 7120) is that the first have a chainline of 52 mm and a QR factor of 172 mm, the second has a 55 mm chainline and QR of 178 mm; the "20" series achieve this with a 6 mm longer spindle and adding a 3 mm spacer each side to keep simmetry; on this frame it looks like the 52 mm chainline barely clears the frame: possible solution is adding spacers to BB or to  crank spindle in driver side; this will creat asymmetry in QR factor, but 1-2 mm I think won't be noticeable. As a general rule the more inner the chainline the better it is.

[Thrill21]

Stefan, I see same color and same progress as me more or less  .
BB issue: I think the threaded BB is the way to go, maybe I will install the stock BB with no inner spacer, just to be sure that I could remove it later; ZTTO BB looks good but aliexpress transit time is approx 15 days : otherwise I see in german online shop token makes same threaded BB, just slightly more expensive.
Chainline issue: the difference between shimano XT 8100 and 8120 (or slx 7100 and 7120) is that the first have a chainline of 52 mm and a QR factor of 172 mm, the second has a 55 mm chainline and QR of 178 mm; the "20" series achieve this with a 6 mm longer spindle and adding a 3 mm spacer each side to keep simmetry; on this frame it looks like the 52 mm chainline barely clears the frame: possible solution is adding spacers to BB or to  crank spindle in driver side; this will creat asymmetry in QR factor, but 1-2 mm I think won't be noticeable. As a general rule the more inner the chainline the better it is.

Included with the frame purchase is the BB and spacer which looks like a 3mm. Would that not help clearance for chainring? I'll be installing tonight and having a look at that...

[Confused]

ZTTO thread together bottom bracket and replacing their bearings with SKY/Enduro/something of known quality will get a solid option much cheaper than wheels mfg.

[darius72]

Included with the frame purchase is the BB and spacer which looks like a 3mm. Would that not help clearance for chainring? I'll be installing tonight and having a look at that...

The spacer in the BB is 2.5 mm and in theory should NOT be installed; to space out the chainring you can space the BB or space out the spindle of the crank; to me the second sound like a better option. Both of them will creat QR asimmetry.

[darius72]

Update: I installed the stock BB with no inner spacer, just to have more chances to remove it later; I plan to order thread in BB, ZTTO or token; if aliexpress is involved is going to take a while.
Chainline: I installed the 52 mm Xt crank, as said before the clearance with the lower frame is minimal, I measured it is 0.8 mm; I think it could stay like this, moving the crank out will harm the chainline: like this is aligned on the 4th gear from the smallest. I think 0.8 mm flex on the chainring will not happen.
Geometry: I put on fork and wheels to work on geometry: my handlebar hasn't much rise, maybe just 20-30 mm, but I feel like adding a lot of spacers under the handlebar, up to 5 cm: is it normal?

[cybrsrce]

Chainline: I installed the 52 mm Xt crank, as said before the clearance with the lower frame is minimal, I measured it is 0.8 mm; I think it could stay like this, moving the crank out will harm the chainline: like this is aligned on the 4th gear from the smallest. I think 0.8 mm flex on the chainring will not happen.

That is pretty tight.  1mm spacer maybe just to give you a little more safety?  You never know how things are going to flex and it probably isn't worth taking some chunks out of your frame.

Geometry: I put on fork and wheels to work on geometry: my handlebar hasn't much rise, maybe just 20-30 mm, but I feel like adding a lot of spacers under the handlebar, up to 5 cm: is it normal?

More important how it feels than looks.  Are you talking about the 30mm of spacers and the stem in that picture (looks great) or adding up to 5cm worth of spacers under the stem?  Most forks have a recommendation of 30-50mm max of spacers.  Raising the bars from there would be high angle stems or, preferably, higher rise bars.   

[darius72]

Yeahhh one mm spacer on the crank spindle is a good idea; I will look for it; In my opinion doesn't worth to use shimano 7120/8120 55 mm chainline: more clearance but worse chainline. The problem is from shimano chainring inner bolts as noted before, probably an aftermarket chainring will have much more clearance.
Under the stem I put 4 cm spacers in the photo and then even 5 cm and it feels ok; for sure with no spacers is too low and looking at the other builds photos everybody used at least some spacer under the stem. Sure it is very difficult to have an idea now with the suspension not properly tuned and with the bike static. Anyway better to cut the fork stem high and have more possibilities later.

[Jal]

I have already received the frame as well. I like it. Apart from small details that could be improved, the frame seems strong and well built. As it's unpainted, I will try to improve those details before finishing it. The bad news is that the Fox 36 (current year model) hits the frame despite being a size L. The air cap barely rubs, but the Grip 2's adjustment dial hits clearly. I think the 6mm spacer from Cane Creek will provide enough clearance. With how complex it is to make a frame like this, I can't believe how they can have such a basic design fault...

[darius72]

I have already received the frame as well. I like it. Apart from small details that could be improved, the frame seems strong and well built. As it's unpainted, I will try to improve those details before finishing it. The bad news is that the Fox 36 (current year model) hits the frame despite being a size L. The air cap barely rubs, but the Grip 2's adjustment dial hits clearly. I think the 6mm spacer from Cane Creek will provide enough clearance. With how complex it is to make a frame like this, I can't believe how they can have such a basic design fault...

Jal, the 3 mm cane creek spacer is enough.

[xtinction]

Something to note about installing a ztto bb

1) it really tight in my frame could be paint over spray or something but i had to use a bb press to get the non drive side in first.

2) as the non drive side is in and if you use the bb tool that is included with the ztto bb  to tighten the drive side bb in be prepared to be the quite long and have a frustrating time trying to aline the tool with the groves of the bb

3) i opted to use a bb cup tool so it was alittle easier but the paint work on the frame is quite thin and scratches off quite easily.

Tldr: if u want perfect paint work, stick with the regular pressfit bb. If u want an easier time with the ztto bb get urself a bb tool that cups over the whole bb.

[darius72]

Question: with cane creek 3 mm spacer do I still need the stock headset lower bearing base? i think the answer is yes, everything looks more stable

[slo]

No, the cane creek is a crown race that is 3mm thicker. You do not need the one that comes with the headset.

With the included headset the Lyrik Ultimate was just about rubbing the frame size large downtube. I installed the Cane Creek +3mm crown race and now have over 3mm clearance.