Author Topic: Long Teng / Mondince aero frame FM126  (Read 240175 times)

Tpower59

Re: Long Teng / Mondince aero frame FM126
« Reply #465 on: July 02, 2026, 12:20:48 PM »
Ok I haven't ridden it much, but I've finally stopped spilling mineral oil everywhere and have it assembled.
58cm and whatever they call the lighter weight option, which is irrelevant as I painted it.

Good first impressions once the correct pieces have actually been delivered. In hindsight, I can't be upset for the delay, it was my choice to be the trial subject for a new frame. Wrong battery holder, wrong bearings, and wrong crown race made me realize how different of an experience buying a frame direct from a factory is. I'm a little surprised that the person manufacturing the frame didn't want to assemble one and take it for a spin, honestly. I still stand by my decision to buy a frame without reviews, as I bought this knowing that the frame would kind of be a gamble. I didn't go for a expensive or ultralight build as a result. I got everything together for just under $2000, buying parts over time since last November. 8.4kg as pictured (cage and computer mounts, pedals).

I did my own version of the stiffness on the wall test, which seems consistent with what's been described. I'm more of an endurance/long distance rider, so I might not actually be able to hit the watts on the road to notice, but I'll update when I've done a sprint workout. My specialized diverge (fact 9r carbon) flexed quite a bit more using the same test, but that bike is known to be quite soft and since there is so much more clearance, I am more worried about the fm126.

I had my LBS cut the fork before I got the correct crown race and lower bearing, which means the fork is just a bit too long. I'll probably have to find a spacer, but if anyone has a link to a slightly lifted top tap on Aliexpress, I'd appreciate the link!   :D

Nice Decathlon Van China
You forgot to tell us your riding impressions

ausmtb8989

Re: Long Teng / Mondince aero frame FM126
« Reply #466 on: July 04, 2026, 02:08:40 AM »
All right, then let’s get back to our highly scientific work. This time, I didn’t lean the rear wheel against the wall or the doorframe, but rather the frame’s axle itself. That means the rear wheel is essentially removed from the equation. Then I asked the Gemini AI how much the bottom bracket deforms relative to the ground. The result is that the bottom bracket of the FM126 shifts about twice as much in the horizontal direction.
As I am in the market for a Chiner frame build, I was interested in this frame till this video i shown.  It really appears to be a noodle frame.  I tried this same test with my old 2013 Giant TCR Advanced SL, and get at most 1mm deflection between wheel and seat stay, and this is using the force of my knees to try to get movement.

Leon1234

Re: Long Teng / Mondince aero frame FM126
« Reply #467 on: July 06, 2026, 06:23:52 AM »
Just an interesting site note: While i was checking the china bikes facebook forum i noticed that someone posted the fm126 frame under a different brand. The brand light-cycling also sells the mondice frames from their website but looks like they are more focused on the b2c and mondice more b2b.

https://light-cycling.com/?v=5f02f0889301

kungie

Re: Long Teng / Mondince aero frame FM126
« Reply #468 on: July 07, 2026, 08:06:54 AM »
Nice Decathlon Van China
You forgot to tell us your riding impressions

Not sure if I should be proud or embarrassed :)

Bike is good, but again, with the asterisk for flex on chainstays. I have ridden it a few times. No surprises on comfort given the SL8 geometry. I rode it 150km yesterday and the positioning and comfort was great. I really like it and am happy. I knew this frame would be a gamble, so I think it is fitting squarely into my expectations. I still want to try some more out of the saddle efforts, but I suspect the real test will be feedback after getting into some quicker group rides (which I haven't been doing lately).

I'm a bit hesitant to my authoritative statements on the frame, as I don't have a lot of experience with carbon road framesets. It feels less stable/premium than a trek madone sl8. Hard efforts feel a little unstable, but it could certainly be me adjusting to a racier road bike. Wish I could provide more, but that's probably all I can say until I get more chances to go fast on it.

Serge_K

Re: Long Teng / Mondince aero frame FM126
« Reply #469 on: July 07, 2026, 09:55:20 AM »
Not sure if I should be proud or embarrassed :)

Bike is good, but again, with the asterisk for flex on chainstays. I have ridden it a few times. No surprises on comfort given the SL8 geometry. I rode it 150km yesterday and the positioning and comfort was great. I really like it and am happy. I knew this frame would be a gamble, so I think it is fitting squarely into my expectations. I still want to try some more out of the saddle efforts, but I suspect the real test will be feedback after getting into some quicker group rides (which I haven't been doing lately).

I'm a bit hesitant to my authoritative statements on the frame, as I don't have a lot of experience with carbon road framesets. It feels less stable/premium than a trek madone sl8. Hard efforts feel a little unstable, but it could certainly be me adjusting to a racier road bike. Wish I could provide more, but that's probably all I can say until I get more chances to go fast on it.

Take your time and dont feel pressured to come up with some review before you've actually had time to review the frame properly.
I would ruthlessly tell Jack that his frame is a noodle and that's completely unacceptable, if you feel it's soft indeed. He dismissed the guy who first did the chainstay flex test here, saying it's normal. That's typical Chinese behavior of not admitting mistakes. But if several people say the same thing, hopefully they'll get their act together.
I stopped interacting with Jack because i lost all interest the moment the frame stopped being 35C compatible (he effectively kind of lied, as far as i can tell), so i have no horse in this race left. Otherwise i'd be on his back.
Almost nobody's going to buy an aero looking frame if it's proven to be flexy AF. If Jack can't understand that then he shouldnt be in this business. ISO tests are a joke, every frame passes ISO, it means almost nothing.

Leon1234

Re: Long Teng / Mondince aero frame FM126
« Reply #470 on: July 13, 2026, 06:09:53 AM »
I was just told by the light cycling contact that they have a new layup with a 130N/mm BB stiffness. Sounds a bit like bullshit to me :D


For comparission this table with different bikes from the nero show (althought the tourmagazine is using a different test as far as i know):
« Last Edit: July 13, 2026, 07:57:56 AM by Leon1234 »

bigApple

Re: Long Teng / Mondince aero frame FM126
« Reply #471 on: July 13, 2026, 09:31:39 AM »
If this is real, i am really pissed. But i actually can not imagine they improved the bb stiffness that much.

Dareios

Re: Long Teng / Mondince aero frame FM126
« Reply #472 on: July 13, 2026, 10:19:08 AM »
If this is real, i am really pissed. But i actually can not imagine they improved the bb stiffness that much.
Also, who needs that much BB stiffness?
I'm pretty sure that would be well above the point of diminishing returns.

Serge_K

Re: Long Teng / Mondince aero frame FM126
« Reply #473 on: July 13, 2026, 10:54:16 AM »
I was just told by the light cycling contact that they have a new layup with a 130N/mm BB stiffness. Sounds a bit like bullshit to me :D


For comparission this table with different bikes from the nero show (althought the tourmagazine is using a different test as far as i know):

Who is "the light cycling contact"? Is that someone at Mondince?

Leon1234

Re: Long Teng / Mondince aero frame FM126
« Reply #474 on: July 13, 2026, 02:18:54 PM »
Also, who needs that much BB stiffness?
I'm pretty sure that would be well above the point of diminishing returns.

I think there are two different approaches to measure the stiffness. The one from tour magazine which are the numbers in the screenshot and a more conventional/basic way where 130N/mm is sort of a benchmark so maybe they are just claiming some number that is used as a benchmark.

Leon1234

Re: Long Teng / Mondince aero frame FM126
« Reply #475 on: July 13, 2026, 02:20:37 PM »
Who is "the light cycling contact"? Is that someone at Mondince?

No I just wrote to a WhatsApp number that is mentioned on the light-cycling website. I also asked what the difference is between the companies and as suspected Mondice = B2B and Light Cycling = B2C.They also changed the model names on their website in the last few days so they are not the same names as mondice anymore.

Serge_K

Re: Long Teng / Mondince aero frame FM126
« Reply #476 on: July 14, 2026, 09:11:31 AM »
No I just wrote to a WhatsApp number that is mentioned on the light-cycling website. I also asked what the difference is between the companies and as suspected Mondice = B2B and Light Cycling = B2C.They also changed the model names on their website in the last few days so they are not the same names as mondice anymore.

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.

Leon1234

Re: Long Teng / Mondince aero frame FM126
« Reply #477 on: July 14, 2026, 11:45:06 AM »
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.

I definitely would only buy the frame from mondice directly, just found it interesting. As they (Light Cycling) still have the mondice logo in the pictures (at least the m on the headtube) i think its the same frame. And i still think the flex is a big issue so i wont be buying anytime soon, at least for my power it dont think it makes sense.

pscrs

Re: Long Teng / Mondince aero frame FM126
« Reply #478 on: July 17, 2026, 09:03:39 AM »
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.

bigApple

Re: Long Teng / Mondince aero frame FM126
« Reply #479 on: July 17, 2026, 09:32:26 AM »
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.