I personally have 4 Chinese cf frames, but one was a warranty replacement for a 'mysterious' cracked seat stay.

The first one was an unknown model and make. Got it before I actually found this site. Anyway I bought it because it was sold for like $200 or so because the supplier send the wrong size. So instead of spending on shipping back the frame it was just sold cheap. I rode it for some 4,000km over a couple of years and decomissioned it in favor of a 29+ bike. Funny thing about it was after disassembling it, I found out the there was a pretty large crack, actually a hole on the underside of the chainstay (driveside) close to the BB. Looks like bashed in, I'm guessing I must have hit a rock pretty bad at some point. But I honestly don't know how long it has been like that. Just lucky it didn't had a catastrophic fail while I was riding it. The thing is, after watching a lot of 'how to repair cf bike parts' in youtube, I know it can be repaired and plan to... if only I don't procastinate.

Second was a road bike from Carbon Speed. After about a year, I had a mysterious crack on the seatstay. It was under warranty & was promptly replaced. It is currently still in great condition but don't get lot of action as I've gravitated toward my 29+ & gravel bikes. The cracked frame, I actually had it DIY repaired for like $5. Converted it into a single speed and had put another thousand km on it. Like the road bike, it doesn't see a lot of action nowadays but it is still in running condition. So that's second & fourth. I also have a pair of cf road rims from Carbon Speed that have seen over 3 thousand kilometers and are still in great condition.

Third one is a 29+ HT that I set up as a full rigid. Also from Carbon Speed. A Trek Stache copy. It is still running but I've been getting an annoying creaking sound on the BB on every climb. I suspect a hairline crack near the BB. I will decomission it for a while as I'm planning to do some experiment with my new 29er titanium bike that is currently in the building process. Hopefully solve the creaking problem as well. To date, this is my most 'fun' bike.

As an aside, my CS cf frames & rims had outlived Carbon Speed. It is sad to see Peter (owner of Carbon Speed) leaving the bike industry for another business venture.

While I had these cracks and creaks, I can't really complain much, for the price, these bikes have served me well. Better than I expected if I may say so. While I've no plans of ditching carbon fiber bikes I have to say that I am gravitating towards titanium frames. It's more of a personal preference than I have issues with cf. And if all the stars aligned, I can actually rebuild or reactivated them & have 5 bikes today with another on the way. 

Btw, my signature shows a brief history of bikes I owned.

@carbonanza, that's a pretty cool looking Garbaruk chainring. I've personally used the much cheaper Chinese Deckas and sort of in between (price-wise) Stone chainrings and wonder how the quality compare to these Russians (or Czech?) Garbaruk.

Alright! Alright! Alright!

1. Contact Waltly, they will help you fill out the necessary numbers. In my case, the most crucial info was the fork length & offset. You can also change the figures as you progress. They will ask for a 50% downpayment before they officially begin with the project planning. Plus the planning stage can take a few weeks.

2. You can just tell them the chainline value you want. While your CAD drawing would help, it is not required. I didn't have that, I just list down the numbers, accompanied by pictures of Niner SIR frame & it's geo-chart. Any numbers I didn't list that they required, they asked. If I don't know, they suggest but I decide. They will come up with the drawing for you to check & approve. And every time you have a revision, the drawings will be updated accordingly.

4. They will inform you if the 40T is doable with respect to your tire size & chainstay length.

3., 5. & 6. I'm afraid I'm not technical or knowledgeable enough to answer these questions.

7. I never asked them but I believe they have a default derailure hanger based on your chosen dropout. They might have options for you to choose. In my case, I was deadset with the sliding dropout with those brackets... so I didn't bother to ask.

8. Top tube mounts for bags aren't a bad idea. It gives you more options for choices of bags (I do see a lots of bolt-on bags on the market nowadays) and mounting strategies. The only hitch I see is bolt-on bags looks/works better on flat top tube. Perhaps you can ask Waltly if they could use oval top tube or offer a square-ish tube. After all, Litespeed Ultimate Gravel Ti Bike is sporting a square-ish top tube.

9. I believe it is worth it. The only reason I didn't have them on my 'Niner SIR' was because I already have a gravel bike with those features. I pretty much already defined their roles. And I believe these added features won't cost too much. It'll probably fit in the basic rate. In fact, I'd go ahead & ask if they can build the rack for that frame.


Suggestions:
1. You could consider your max tire to allow you to slap on a 27.5+ tires. I had consider the idea but having rode a 29+ and extremely loved it, I know I want a dedicate 29+. But just a thought.

2. You might want to tell them if you want polished or brushed or sand blasted (?) finish. While I didn't ask, I have a feeling you can have mixed-finish.

3. If you have pictures of features you like/want, show it to them. They will let you know if it's doable or not. Heck, we took a month of trying to make that 420 chainstay length on a 29+ frame work but we couldn't. What I mean is, they will try to give you what you want. You may not always get it but at least it wasn't without some effort.

Absolute Black's offer to chain lubricant... Graphene.

https://www.cyclingnews.com/amp/news/absoluteblack-launches-new-graphene-chain-lube-with-huge-longevity-and-efficiency-claims/

I don't see in the picture an opening for the belt.
Do you think it is a breakable belt, I've seen some picture once, but don't know if it as reliable as a regular belt.

The Commencal Acid is not belt driven, the photo just wasn't of the best quality. I've personally seen the bike locally, iirc, it was a $300-350 fixed gear bike. Kind'a heavy for a fixed gear but I just loved the design.

Some detail shots of the frame.

It's my second custom titanium frame from Chinese company Waltly Titanium. That should be enough to say that I was very happy with the first one.

This project was finalized around March 24th. But Amy of Waltly and I had been on the planning state since Feb 11. The main reason for the long planning was because my original project was a 29 plus bike but we hit a lot of bumps and what I wanted & would not compromise... a rather short chainstay, was as of now, not doable. I can't fault them at that as I am aware it wasn't going to be an easy task to do with titanium. Still we went at it for about a month until I settled with my fallback design, which is a 29er largely based on a Niner S.I.R. 9. Also holidays in China got in the way too. In the end, all I can say is Amy had extraordinary patience & very accomodating.

While the frame was finished and shipped to me as early as May 9th, it is only today that I received it. The long delay was caused by the COVID-19 lockdown. But it's here now and I'm pretty excited.

I'm sure the first thing you'd want to know is the weight. Well, it's actually lighter than I expect it would be (which was over 2kg) but it tip the scale at 1.952kg (this includes the pair of brake/TA/dropout brackets but without TA).

(Edit) 1.952kg also includes seatpost collar.

These were the features I wanted for this custom bike frame:
1. tire clearance for 29x2.35
2. boost rear hub (12x148) thru axle
3. 44/56mm head tube for tapered fork (1-1/8" - 1-1/2”)
4. internal cabling (brake hose, rear shifter cable & dropper post)
5. sliding dropout for post mount brake
6. seatpost 31.6mm
7. 3 bottle cage mounts
8. water drain hole under BB & chainstay
9. curved seat tube (like Niner SIR)
10. oval chainstay tubes
11. threaded bottom bracket BSA (English 73mm)
12. Ti tubes with polished finish
13. set rider weight w/ gears at 200lbs (91kg), I'm 165lbs (75kg)
14. 40T chainring