Long Teng / Mondince aero frame FM126

[pscrs]

Excellent description—that really nails it when it comes to the riding feel. I feel exactly the same way about steering precision and bottom bracket stiffness. I think the frame’s head tube stiffness is outstanding, in contrast to the bottom bracket.

Agreed I do think the front of the bike feels stiffer than the back for sure, that huge fork and deep head tube help a lot. Really splitting hairs here the section of the fork is wide Id have likes to seen some thinner profiles on those tubes along with the really deep fork, probably.

I do think it does handle really well just a bit underwhelming out the saddle but again the way it rides is way better than than the flex when leaning on it suggests it might. It's still a good bike in all honesty. I like to think my comments would be the same even if I didn't know about the stiffness concerns, which to be honest I was really worried about before receiving the frame. 

I'll make sure to come back with some longer term comments.

[Leon1234]

I am still on the edge about which frame to get. I really prefer the design and look of the mondice over something like the lcr020 or even the new xmcs. Currently I have no real time pressure to decide but I would really like to build up a new bike this year

[Serge_K]

I am still on the edge about which frame to get. I really prefer the design and look of the mondice over something like the lcr020 or even the new xmcs. Currently I have no real time pressure to decide but I would really like to build up a new bike this year

If you have time on your side, waiting before you buy this frame could mean a better layup. It's an open mould, if enough people complain about the BB stiffness, at some point they'll change it.
You could also email Jack to complain about it directly.
I think the reviewer hit the nail on the head: the down tube may be so slim that it's laterally soft. Chinese sellers do not usually ride bikes, and they don't have the watts anyway to push the equipment, and do not usually do layup iterations based on human feedback. There are iso norms and they solve for that.
Anecdotally, the aerotrace from velobuild just lost 150g from using a different layup and T1000.
If you buy now, you're a very early adopter. Pretty much a beta tester.
One of the reasons these frames are cheaper is that early customers are beta testers. But that part is never advertised

[BeR]

Be very careful. Never heard of them. Where did you find them? The website is not serious, and the company (empty shell, really) is 1y old only. Wont call it a scam, but i think i can vibe code the same shit in one afternoon and i m pretty sure registering a HK company costs a few hundred bucks and is dead easy.
https://www.ltddir.com/companies/light-cycling-sports-equipment-co-limited/
They are like velobuild, in that they're clearly a broker. But velobuild has built a reputation after trading for years and years.
If you're going to buy the 126, you're better off buying from the factory (long teng, Alisa will sell it to you if you ask) or Mondince (long teng related party) than from these people. Without hard evidence, i also wouldnt believe they changed the layup, as Mondince brushed off the topic as a non issue. If it's another factory using the moulds, then idk if they share the layup schedule (it is an open mould frame).
Honestly i'd stay away. Unless and until Jack shows that the frame is sprint friendly, i dont think it makes sense to buy that frame. And apparently, he doesnt seem to care.
I also note that some users (like BeR) have reported not noticing anything wrong with the frame flexing at the BB, but why take the risk? My 268 doesnt have nearly the same flex (i repeated the door test) and i can't see any scenario where it would make sense to take such a risk. To be clear, sprinting is one thing, but if you're bombing down a descent at 70+kmh, and you're doing hairpins, the idea of a pool noodle is straight up terrifying (you want something that tracks, not fuzzy lines). If your FTP is low, you dont sprint, you dont race, you ride on the flat, then you're fine, but it's still not a good reason to buy something that's potentially truly impaired.

After reading this post, I wanted to find out more, so I looked into this seller (Light Cycling). I’ve been chatting with him a lot lately, and honestly, he is super responsive and answers absolutely every question.

 First thing: I really think that this is not a scam. To clear things up, He sells the exact same frames produced by Long Teng.

So, the real question is: Why choose Light Cycling ? In my opinion, there are three main reasons:
1) More choice is always a good thing: We already know these frames are high quality, so having another reliable alternative on the market is great for us.
2) A focus on custom paint: This seller really wants to stand out by offering high-quality, unique paint jobs. He’s currently working hard on this project and should be sharing photos within the next month to show what he can do.
3) A new mold in the works: He also aims to develop a brand-new road bike mold. If the seller listens to our feedback, we could end up with a frame that perfectly matches current market expectations.

Anyway, I recommend reaching out to him if you're in the market for a new frame. The best way is to message him directly and form your own opinion.

Personnaly, I think that I will try to order a frame from them. I will keep you inform.

Because this topic is about the FM126, I will also post this message under "Vendor Discussion & Reviews".

[bigApple]

Another shock is on the way. The seat tube of my frame is starting to crack. Let's see what Jack has to say about it. The pattern of the crack and the view of the seat tube from above show that it's not just the paint—it's clearly the carbon structure, unfortunately.

[Serge_K]

Another shock is on the way. The seat tube of my frame is starting to crack. Let's see what Jack has to say about it. The pattern of the crack and the view of the seat tube from above show that it's not just the paint—it's clearly the carbon structure, unfortunately.

That's a high stress area and it does like a structural crack given it propagates on 2 sides. I remember that velobuild users (pinarello clone) managed to DIY repairs in that area, but you should absolutely get a replacement. The good news is you'll probably pay for shipping for a new frame, get to keep that one, and with a 30 dollar repair kit, you can end up with 2 frames (you might have to order a new fork and seat post, as I wouldn't send you an extra fork and seat post if I were them). If you're bothered by the flex at the chainstays, keep in mind they're somehow tied to long teng, so you could potentially get a different frame that's proven (like the 266 or 301 or whatever). I don't recommend my 268 anymore because it's from 2021, but it's still my daily driver and I'm finding it very hard to justify changing it.

[bigApple]

Jack wants to send me a new frame. I'm curious to see if it works out and if anything has changed about the frame compared to the first versions.

[Leon1234]

Jack wants to send me a new frame. I'm curious to see if it works out and if anything has changed about the frame compared to the first versions.

That will be quite interesting but i doubt that they already changed the layup.

[Spongel]

Hello guys,

stepping in right in now as I am much much interested in this frame and have some serious thought we can discuss about.

Backstory: Just built a Mondince FM336 Gravelbike a month ago. Loved the process, love the riding. But its a gravel bike and it has its own use case which is not speeding on roads. It performs great on gravel. I initially chose size L and think its a very good match. So far I am very pleased with mondince.

Because I also want to do some races and/or triathlons in the future I am thinking about building up a road bike. I asked Jack if he has a road frame and answered with "yes, the fm126". Then I offered, I could produce a buy and build process video on youtube for this particular frame. His answer was, that he can send me the frame for 450€ only - but I have to mention Mondince as brand (no details yet actually in which way he wants me to place the brand).

Keeping the 450€ in Mind its almost a no-brainer. But there is this flexy BB issue which could be kind of dangerous for me: 185cm tall, 90kg heavy.

Do you think I should still consider this frame? Another way to go would be the LCR018D (but its more of a allroad endurance and not meant for racing), the not yet released LCR020 or the fully built up Seraph TT-X71.

I read so many threads about all those frames and the more you read the more issues you find. Its frustrating diving into a rabbit hole and overthink stuff   

Loooking forward to your replies!

[Serge_K]

Hello guys,

stepping in right in now as I am much much interested in this frame and have some serious thought we can discuss about.

Backstory: Just built a Mondince FM336 Gravelbike a month ago. Loved the process, love the riding. But its a gravel bike and it has its own use case which is not speeding on roads. It performs great on gravel. I initially chose size L and think its a very good match. So far I am very pleased with mondince.

Because I also want to do some races and/or triathlons in the future I am thinking about building up a road bike. I asked Jack if he has a road frame and answered with "yes, the fm126". Then I offered, I could produce a buy and build process video on youtube for this particular frame. His answer was, that he can send me the frame for 450€ only - but I have to mention Mondince as brand (no details yet actually in which way he wants me to place the brand).

Keeping the 450€ in Mind its almost a no-brainer. But there is this flexy BB issue which could be kind of dangerous for me: 185cm tall, 90kg heavy.

Do you think I should still consider this frame? Another way to go would be the LCR018D (but its more of a allroad endurance and not meant for racing), the not yet released LCR020 or the fully built up Seraph TT-X71.

I read so many threads about all those frames and the more you read the more issues you find. Its frustrating diving into a rabbit hole and overthink stuff   

Loooking forward to your replies!

I would flag to him your concern. And tell him that if the area isn't stiffened you'll do a ride review and you'll probably find the frame so soft it's unnerving.
If you only make a video about the build and don't say anything about riding quality then we'll all collectively hate you and call you a shill
Myself, I wouldn't buy one, I'm 85kg. There are plenty of options that are known not to have that problem. Plenty of scenarios, especially descending, when you want a frame to behave reliably. If you have to slow way down because it feels weird when you're balancing your weight side to side, better buying something else. Safety and enjoyment do matter more than 200 euro.

[Spongel]

I would flag to him your concern. And tell him that if the area isn't stiffened you'll do a ride review and you'll probably find the frame so soft it's unnerving.
If you only make a video about the build and don't say anything about riding quality then we'll all collectively hate you and call you a shill
Myself, I wouldn't buy one, I'm 85kg. There are plenty of options that are known not to have that problem. Plenty of scenarios, especially descending, when you want a frame to behave reliably. If you have to slow way down because it feels weird when you're balancing your weight side to side, better buying something else. Safety and enjoyment do matter more than 200 euro.

Fair enough haha 

I got some interesting news for all of us who are interested in the frame. I shooted Jack some Questions:

"1. Some riders reported noticeable BB/downtube flex in wall tests vs other frames. Did you change the layup or tube design since then? Is the current batch updated? Do you have a BB stiffness value (N/mm) — not just "passed ISO"?
2. I saw a report of a seat tube crack after a few weeks. Was the cause found — one-off or known issue? I'm ~93 kg with a strong sprint. Is the frame rated for that? What's the rider weight limit?
3. For size 58 shipping now: which head tube angle (73° or 74°) and which crown race version (old/updated)?
4. Real tire clearance for size 58 in mm? Does a 32 mm tire fit with room on a 25 mm internal-width rim?
5. Realistic production + shipping time for size 58 in my paint choice?
6. Which frame would I get when paying the Euro450 - normal, super light or ultra light? And is a custom paintjob included?
7. When you say I need to share our website link on my social media I understand, that I link your website in the video description and mark the video as an Ad - is that right?"

He answered:

"1.We have improved this stiffness issue.
2.it may manufacture issue. We have provided a new frame for him;
3.We will provide new crown race.
4.it is designed for 32mm tire.
5.We have size 58cm in stock. And it will need 18 days to do the painting;
6.we just have one version now. Super light one;
7.yes, show our website and leave feedback about this model"

Think the most important part is question 1. Since we dont have any new orders yet we cant confirm that I guess

[bigApple]

The correct answer is: “We're trying to provide him with a new frame.”

I don't have it yet.
But so far, Jack has been very reliable when it comes to things like sending the new fork crown.

When the time comes, I'll be able to directly compare whether a new layup has actually improved the frame's stiffness.

[Tpower59]

Really impatient to know if the new version fixes this ! Could replace my TT-X68 with this

[Xtakayamax]

So, I finally received mine after quite a bit of back and forth with mondince after having a custom paint that went not to plan. After a fair bit of negotiation I paid a  bit extra to go for the UL version (basically to make sure i was getting a fresh frame) in raw carbon (the frame weight with hard ware (no headset) and thru axle still in came to 950g for a 54 considering this is a raw carbon gloss finish claimed weights are just not representative but this is still reasonably light all the same)   and I did get the mondince branding which honestly looks much better than expected in person.

I received both seat posts and most hard ware in black as well as gold which is great as I have loads of spares. Headset bearings the crown race didn't present an issue on my frame at all (so that appears corrected for me too as well as others). The frame appeared to be well made from what i could see shining a torch in there and construction all round pretty solid. I used the 8mm bearing on the top and the 7mm on the bottom, the fits of the headset bearings in the seats were reasonably tight so not super easy to remove by hand, this is good a sloppy headset bearing fit can lead to issues down the line. I did end up facing both front and rear brake mounts however they really both only needed a touch up and would have been able to get a good brake set up without. Same goes for the t47 threads that I chased but honestly i picked up so little material that a BB would've gone in fine without.

The build itself was really straight forward with the fork routing fully guided chich made life really easy. The di2 mount for the seatpost worked great and wasn't particularly fiddly to install. NB for those this eurostyle brake orientation. The entry hole in the steerer is firmly on the right hand side and depending what kind of set up you have if you have to cross the hoses inside the frame rather than in the bars or stem, like I had to since I was using the PRO headset and stem system youll likely getting biased steering. As a result for this build I went back to a UK orientation (left hand lever rear brake)
Only big comment I have is that currently I have is that on 52t rings im quite close to the top of what the fd allows - I want to move to bigger rings asap but I may need to do a bit of thinking about what will actually work for me considering this limitation.

Like other people have noticed that bottom bracket area does flex, I think theres two problems theres a huge amount of material above the bb this kind of does nothing and i youre looking at the bb it is not encased by that shape (I hope that makes sense) I think as a result the bb area is not as stiff due to this and a really narrow down tube i think if they had effectively moved that large area above the bb down and were willing to widen the down tube as it meets the bb it wouldn't be so bad. The chain stays whilst quite tall are really thin. Head tube is actually quite a bit more hourglass shaped than pictures suggest, I don't think the super narrow down tube is necessarily a bad design choice either. I know a lot of people here want more tyre clearance but I would've like to have seen tyres tun closer to the down tube and the back of the seat tube. There's far too much daylight in those areas for my liking oif were wanting to make a "fast" bike.

Honestly the bike felt fast, on my old 2018 scott foil i had a really fast set up and this will be my reference point. On open flat sections and down hills the bike really did feel like it wanted to pick up speed and hold it nicely. Geo wise just going off the charts i think these should've been fairly similar bikes the mondince is 5mm shorter 3.5mm lower. That being said head and seat angles are quite different. This bike felt short in comparison to the foil and i'll likely bump up to a 130mm stem at some point, I probably should've gone for the 56 (i'm a real 54/56 straddler) on this one. Despite the stiffness concerns people have the bike so far after three rides handles really well i'm super happy to take risks in corners on this thing without second guessing myself. Which I think brings me on to the stiffness thing, I honestly dont think its as bad as people say it is (NB im about 75kg and riding the 54 i suspect it might be worse for taller, heavier riders). It honestly feels fine - buut not excellent whilst it doesn't bother me my foil was really stiff and I loved it, that bike felt alive out the saddle and up hill. By comparison this bike doesn't feel quite as lively, but im not about to condemn it either. People still waiting on one, its likely to not be anywhere near as bad as you might think, people thinking of pulling the trigger honestly so far its a good bike I'm really enjoying it and I dont think id necessarily discourage anyone. Herein lies the issue though, with the Velobuild Aerotrace having just been put on a diet and Light Carbon about to release the LCR 020 D I think this becomes super hard to recommend considering those options exist, and honestly if I wasn't desperate to get my hands on a new frame after selling my foil I may well have waited for either of those. In all I paid i think if i recall £630 for the UL frame and shipping for that kind of money i do think it's worth a shot.

Thats an excellent description. couldn't be better than this, thank you for taking the time.
Do you feel that the flex is only on the BB? how about the front end of the bike? as a 190cm with 79kg I am a bit afraid that there is too much leverage on the whole bike as tubes get longer and I would feel it more flex than people riding smaller frames, specially on the front end which bothers me the most on other bikes I had in the past.
Also, are those wheels from them or from somewhere else? the build is looking fantastic.

[bigApple]

Hey guys, got mine replacement frame today.
I can see they improved things.
E.g. the mounting of the bottle cage screws inside the downtube.
Unfortunately the frame is broken, see the Video.
Transportbox is not damaged, so i guess it happened before packaging.
Very frustrating.