BXT-MTB-117 150mm AM bike

[daifanshi]

Thats the "updated" AM831: http://chinertown.com/index.php/topic,3593.0.html
Original: http://chinertown.com/index.php/topic,3172.1245.html

Some are happy some are not.

Has it been confirmed these are the same mold for the rear? The specified bushing sizes for the BXT MTB-117 (24/24mm) and the Tideace/Haideli AM831 (30/22mm) are not the same.   The front triangle is obviously different which likely explains the 30mm vs 24mm bushing, but the rear is different too.  Or does the actual measured come out the same?

Also, the derailleur hangers don't appear to be the same.

[Spoker]

I seem to be on the same track when it comes to warranty on the frame.

[vintagemx.bt]

It seems have some update on BXT 117 frame.
Initial version was similar to tidace AM831:

[vintagemx.bt]

Upgraded version use links with through axles:

[vintagemx.bt]

Link axle was the main issue of similar tidace am831 frame...

[FullCarbonAlchemist]

Those swing links look much more solid. My first impression of the 831 — before we even knew about the flex/play issue — was that its links looked like they’d have questionable longevity.

[promoto]

My 831 with the upgraded rear triangle is holding up fine with around 1300 miles of trails with jumps drops and janky rocks and roots, Turned out to be a great frame in the end, still love mine

[daifanshi]

Those swing links look much more solid. My first impression of the 831 — before we even knew about the flex/play issue — was that its links looked like they’d have questionable longevity.

My son built up this frame (BXT MTB-117).  I can confirm that all the pivots are now thru axle.  I have attached a picture of the top pivot.  It's massively overbuilt.

A few things to note:

1.  The rear post mounts are default for 180mm rotors (not 160mm as shown on the specs.)
2.  Internal routing was fiddly and in the the case of the rear hydraulic hose, a little tight at the head tube.  Either the opening diameter was undersized, or there was a burr in there. We needed to open up the hole a little.
3.  24mm bushings for the shock pivots.  Some places still show 22mm.
4.  I do not know why some people seem to think this is some updated version of the Tideace AM831.  The dropouts, bushing sizes, BB mounting standard, and general look are not the same as the latest generation of the AM831.  The front triangle on the BXT is missing the dated "camel hump".  This bump might have been cool in 2015, but not today...
5.  My son is notoriously hard on his bikes and so far there are no issues with flex or failures (but he is under 140lbs so YMMV.)

[Jotegr]

Well that looks way better than the AM831

[Chewy]

Anyone else running this frame?
Seems like the best value chinese carbon frame at the moment - $1150 AUD delivered off aliexpress.

Can a 180mm dropper be used on a large frame?

[daifanshi]

Anyone else running this frame?
Seems like the best value chinese carbon frame at the moment - $1150 AUD delivered off aliexpress.

Can a 180mm dropper be used on a large frame?

The seat tube is interrupted by the shock.  You might be able to fit a 180mm if you are long legged.  My son has a 150mm on his and can probably fit a 170mm.   

[grinchy]

I placed an order for the BXT-MTB-117 a couple weeks ago. After a few days of the typical questions (verify color, size, address my Q on weight and layup) it's gone into the production schedule with around a 10 day paint timing.
It's definitely not the AM831, I was quoted 3300g weight. The AM831 was running around 2400g. I don't love that it is this heavy, but I think this is a result of the previous stiffness issues with AM831 and the solution was to lay up a lot more carbon. The Hightower CC is 2890g with shock, so around 2500g no shock. At 800g more, the BXT is edging into the HighTower AL frames' weight, which are around 3800g.
Even with the heavier frame my build out using mostly hand-me-down parts and a X2 Pro rear looks to be around 31.5lb, so respectable. This is using i35 alloy rims.

As long as it's not rolling weight it isn't too much of a big deal, what doesn't kill us will make us stronger

[grinchy]

I finished my BXT-MTB-117 (v3) build. It's sweet. Only very minor issues (no directions on the washer 'direction' on the upper pivot lower bolt, one cable housing point on the HT was too tight for the brake housing).

I don't have a lot of miles, but no reason to believe any issues coming.

Mine was about 3100g (fully painted in white gloss). I weighed everything and documented the build on MTBR here:
https://www.mtbr.com/threads/hightowur-v2-open-mold-carbon-build.1222774

[grinchy]

My size L measures around 11.5" of seat tube depth. I did have some minor resistance to putting the seat post all the way in, but I couldn't see any flash so kept on pushing and steady pressure got past the tight spot (which was around 10" down.)

I can fit all of a 170mm PNW loam dropper in the seat tube.

[TIMDOR576]

Thanks for all the info and build documentation! I'm in the market for something in the 130-150mm travel range and might go with this frame.
Grinchy, your BXT experience wasn't bad? I think that's my biggest concern right now.