Dumb question incoming: does anyone know what the heck this is?

I was cleaning my drive train, specifically the cassette, when this plastic thing fell off. (At first I thought it was a huge piece of gunk lol.) Is it part of the rear derailleur or something?

Thanks,
That's exactly the kind of info I was looking for. It seems like I'll probably be okay with the 52 then. What length of stem did you go with?

This frame seems to fit the bill for what I'm looking for. Also Alisa said that the thru axle issue has been completely solved as soon as someone brought it up.

I don’t have a slammed cockpit (just thinking about that makes my back and shoulders ache…), with about 4mm drop from my saddle to stem. I have a 100mm stem, 110mm would have been fine too. I think with my size, the 52 is just right. With a 50, I suspect I might be a bit too far forward in terms of weight distribution.

I should ask Alisa to send me the right through axle!

I was curious if we could get any ride reports from the members who built up the frame?
I'm heavily considering getting this frame in the near future and was just wondering how it felt ok the road and if anyone could compare it to any other mainstream bikes they've ridden?

Also how offset is the seatpost that it comes with. I've been trying to figure out what size frame to buy. With the offset post I'm leaning towards 50/52. I am 170cm tall with a 79cm inseam?

I'll share some impressions. I'm only at around 500km logged on the bike and I'm comparing this to my previous bike, which is an older 2013 Scott CR1 Pro, so take this FWIW.

- Handling is neutral, as you'd expect from its geometry. It's not a twitchy race or crit bike, but it's responsive enough and confident through corners and on twisty descents. This is something I appreciate, coming from my jittery Scott.

- Ride quality is pretty compliant. I can feel the road but much less of the impact vs. my Scott, if that makes any sense. I have 32mm tires (on wheels with steel - not carbon - spokes) so I'm sure that contributes to the ride quality.

- It's pretty fast. Compared to my Scott, I average 1 - 1.5 km/h faster on my endurance rides. I haven't done too many high intensity efforts but I expect the aero qualities to shine through even more when I do.  I don't know if this is just about the frame from an aero perspective: I put on narrower 38cm bars and 45mm wheels, so it's probably the overall package.

- I took the bike on a local climb that averages ~7.5%, where aerodynamics don't come into play, and set a PB (even though I've done mostly base miles recently). This bike is pretty close in weight to my Scott, so it wasn't about weight savings. On steeper climbs, it's more about power and rolling resistance. Frame stiffness (and that ginormous T47 BB) probably helps with more efficient power application, and my new-ish GP5000 with TPU tubes contribute on the rolling resistance front. So the whole bike probably contributes to added speed on climbs, not just the frame.

- Acceleration is pretty good. I mentioned before that on my first few rides through traffic, I had to soft pedal a few times when I found myself getting up to speed a bit quicker than what I was used to.

So, overall, I think the ride is pretty much the all-arounder that it's billed as. I've been pretty happy with it. I haven't ridden other Chinese frames or more modern big brand frames to make those comparisons, but I think what Peak Torque said in one of his videos is probably right: once you get these Chinese frames built up, it's hard to tell them apart.

The seat post offset is around 20mm but you can ask LT to confirm.

I'm 174cm with 78cm inseam and got the 52, which fits me pretty well. I almost got the 50 because I was also a bit worried about the seat post offset impact on reach, but the 52 worked out well for me with the narrower bars helping to reduce the reach a bit to fit me.

Hope this helps!

This thru axle gives 3mm more capacity. It fits if you trust 2mm is enough.

https://www.aliexpress.com/item/1005007535904782.html

Is the problem that the thru axle is too long? Or is the problem that the threaded part is too short?  If I use the washer/spacer as LT advised, does this create any potential issues for rider safety or frame integrity?  Thanks for your patience on this .

@kwantani I believe it's a standard "M2" washer with 20mm outer diameter and 12mm inner diameter. I called around and one LBS has it, I'm also going to check some hardware stores. I'll give this a try and see what happens, but if the thru axle is the root issue, the washer is a temporary solution until I replace the thru axle.

Looks like the axle does not thread in enough, guessing the spacer would solve it.
But you can find out yourself easily, what happens if you insert another set of wheels?
Any bearing play in the wheelset (maybe test on another bike)?

I only have this bike and wheelset  

I do plan to try the washer. I’ve read elsewhere that others have the same problem, hope this solves it.

This frame is super intriguing but I'm struggling with the Trek headtube lol. Does the frame look... good/fast in person? I know it's subjective, but does it pass the vibe check? Also is there a tangible ridge down the center of the seatpost?

Yes there is a ridge down the seat post.

As far as looks, yeah this is completely subjective but here is my completely subjective take: it does look "fast" because of its aero profile which is the same/similar profile of just about any other aero optimized frame: over-sized tubes, dropped seat stays, sloping top tube and an exposed aero seat post, and especially if you go for an integrated cockpit with narrow bars, disc brakes and deeper rims.  But does it look "good"?  I'm less of a fan of the kitchen counter-top wide downtube, and am more into more classic looking frames with reasonably sized oval tubes. So that's why my next project is probably going to be something more Crux and Aethos like, or maybe even a Chinese Ti frame.

for my cover, there's nothing need to be "aligned", the cover closed and locked snugly. Just with bare hand I can lift the cover so easily. Mostly likely the whole piece will fell off easily over a bump. Currently I'm tying a velcro strap over the downtube to strap it down just with a piece of mine.

UPDATE: Long Teng now blamed the excessive paint on the edge of the cover  and downtube that prevent the cover to be locked securely, want me to use a rasp to grind off the excessive paint on the edge along the cover and the downtube opening 

Well, here is how mine looks: https://youtu.be/eT8vtAXO97c?si=5btSdcJY2rwItIvu (internal storage updates at 7:15). It's not a big issue for me, fortunately.