Chinese Carbon MTB Forums
News:
Happy Holidays!
See likes
See likes given/taken
| Post info | No. of Likes |
|---|---|
|
Re: Why are road bikes more popular than mountain biking?
It's actually other way around where I live - MTBs are far more popular than road bikes, even among people who ride in the city
December 30, 2023, 08:16:17 AM |
1 |
|
Re: Consensus on replica frames ??
There is a lot of space between a frame being safe to ride and being the quality you see even on second tier frames from the big brands. It’s worth thinking about the economics of a replica frame selling for $500 painted up as a Factor or Pinarello. I know that it would cost me about $2000-$3000 USD to get a contract manufacturer to make, design a layup for and test a handlebar. I would guess that a frame would be on the order $10k-$12k. It’s probably a breakeven at 50 units at a factory cost of $300 and 30 at less than $200 to make money on a replica frame. To sell 30 frames, you probably need them to pass basic fatigue and safety tests to make sure you can sell even that many. Your don't have much additional budget for development so other than a 3d scan of each frame size to get the shape right and some basic cad work to smooth out the details from the relatively low resolution of that scan, and then work to get the layup good enough to pass the testing. There isn't much budget for additional work. While external tube shape is the majority of the strength of a tube, thickness still matters for stiffness. Because you are using lower quality materials you will end up with thicker tubes, a really stiff bike, and a heavier frame. Its probably been tested enough that it wont break, but will also likely inherit the flaws of the original design because on the outside, it needs to look like the same. In the case of Factor, they replaced their headset assemblies and changed the design since the Ostro VAM was pulled from competition in 2021 due to sheared steerer tubes. Are you getting the corrected versions of the parts on the Ostro VAM replica? Are the parts even of sufficient quality to avoid the problems that led to the re-design? Can these replica makers get the details of a C shaped steerer right enough to be reliable in the long run? What about the headset and derailleur hanger hardware? Potential headset issues also track with the flaws seen on Cervelo replicas which also use a non-round steerer. The Pinarello Dogma F suffers from a surprisingly high incidence of cracked seatstays and chainstays as a result of the asymmetric design. The Velobuild version also seems to have this problem. Plus you get bonus headset problems. An open mold is usually a little more expensive. But, because it's a clean sheet design, they are going to design it in CAD and run the basic FEA stuff and use the results to iterate the design. They have both a good understanding of where / how to adjust the layup and the freedom to change tube shapes to get the performance they are looking for. It looks more generic, but the engineer and designers are incentivized to maximize compatibility with 3rd party components and make the best riding bike they can within their budget because they are looking to secure sales for dozens of bikes with multiple small brands. As a result, these bikes almost always use forks with round steerers and common headset sizes that are easier to design, to make to a high standard, and possible to source from 3rd parties. A branded version of one of these open mold frames from a brand that does development like a Cinelli or a Guerciotti might ask for layup adjustment, will do some additional QC and swap out the generic hardware for branded FSA or Deda versions. They might stick them in a wind tunnel to help find the right handlebar and wheels to sell with the frame. They might also swap the fork. These bikes win big races at the U23 and junior levels, cost 3x as much, but generally speaking most reviewers will say they fall short of the mid-range bikes from the big brands. Is the replica safe to ride? Probably, but the commercial motivations are totally different and there is a reason why the open mold is more likely to have the details sorted. So yes, there is an inherent reason why the replica is likely to be a worse bike. January 01, 2024, 04:19:05 PM |
1 |
|
Titanium custom gravel build
Almost ready
January 21, 2024, 07:53:17 AM |
1 |
|
Re: Seka Spear
IDK there was a lot of mod cleanup on that WW thread, so its hard to look at it now and see who is really at fault. One thing I find interesting between Elilee, Seka, and Bross is the insistence that the geometries are more friendly to Asian people. As a result they claim to have made the bikes taller and with less reach. I question if that actually makes sense if the the thesis is that legs are shorter and torsos are longer. If that were the case a rider with the same back and arm angles should have a lower seat height, lower stack and a longer reach. Unfortunately Seka's race geometry is only equivalent to a Tarmac geo. Realistically, it seems like these brands are largely making endurance bikes that look like race bikes, which is probably a good commercial decision for them. As someone who also has shorter legs and a longer torso, a size 49 SL7 was cramped with weird weight distribution while a size 52 fits with the 110 -12 stem but barely as it bordered on too long and too high with the available bars for that bike. In hindsight a narrow bar like the Aerocoach Ornix + a 120mm or even 130mm stem would have probably fixed it but those weren't available then. This is why my road bike is currently a self designed Ti thing made by XACD. April 30, 2024, 10:46:22 AM |
1 |
|
Re: Lightcarbon: New LCR017-D (or Yishun R1058-D)
Took me a bit longer to make this post. Overall experience has been really good. The fit of everything was spot on. Full build came in at 15.2 lbs without pedals (size 52). For being that light, I am also surprised at how stiff it feels in accelerations. My order was handled well and had great communication. I really like the color but it is more purple than I expected, but it looks great. You can see in the sunlight it has the orangish chameleon, but the purple is the dominant color. Paint selection was LCB-02HS. Current setup is gp5000 28mm, but have a second wheelset with 32mm gp5000. One bummer is the width of handlebar options. I went with the 40 x 110 handlebar and I have been running narrower bars and would have selected narrower, if available. I will quickly address some of the items on this thread: My frame has a drain hole under the BB I will say that the layup feels pretty thin below the bottle cage on the downtube. It is a larger tube size, but the wall thickness feels thin. Brake caliper mounts are faced Rear thru axle does require more torque than other frames (but doesn't appear to be any thread damage, so I don't know, not really an issue to me, but a previous poster described this). I had to cut the seat tube to get my fit right, but just 1/2" or so. I also ran into an issue with the seatpost clamp. After riding I needed to adjust, and upon retorque the clamp to 6nm something with the pins that hold the bolt broke. I have contacted LC and will update with how quickly they respond. I am pretty sure their clamp is a tried and true design across other frames, so I am not quite sure. I want to tear it apart to see whats going on but it is kind of a captive part. May 13, 2024, 09:24:21 AM |
1 |
Re: Seka Spear
I've been wondering why I have not been able to hit the sort of speeds on descents with my current bike compared to bikes in the past (I had taken a break from cycling for about 5 years). I weigh about 10 lbs more, my kit is much more aero nowadays, my helmet is aero, my wheels are 45mm deep instead of 25-28mm depth, my bike weighs about 3 pounds more, I typically carry a lot more food and water and I'm still not hitting the speeds I had been. Learning about the differences in Chinese geo vs Western geo yesterday when reading about these frames made me realize the frame I'm on now is much more 'western' and the frames I had been riding previously were Chinese geo. So all those new advantages in weight, equipment aero are nothing compared to the more aggressive body position Chinese frames will put you in. Something I found interesting. I'm typically topping out at 4-5mph less on many of my regular descents in a tuck now vs a tuck then. Just to point out, the prevailing trend is to fit higher stack, longer reach, narrower handlebar, minimum saddle setback, shorter cranks. Basically to try and achieve the same (or more aggressive) hip angle as you'd get from the old slam-that-stem bike-fit, but move the arms and hands further up to make the aero hoods position easier. (see Victor Campenaerts's latest Orbea Orca video) I've been racing for 16 years and have adopted the new fit trends, and can attest that since then I'm typically topping out 1-2mph higher, and easily setting PRs on flatter/rolling segments, despite being fatter and slower than I was a few years ago before making these changes on my new bike. If you find yourself going slower on a modern bike I really suggest you go over your handlebar position and try to get longer and narrower. My Seka's Exceed geometry has a fairly high stack (although is now actually quite normal compared to Cannondale's S6E, or the Tarmac).But a big knock I'll give it is the short reach and relatively laid back seat tube angle. To achieve the "modern" bike fit, I have struggled to fit a properly long stem, and have to slam my saddle all the way forward on a zero-setback seatpost. The Spear seems to have at least addressed these two shortcomings with slightly longer reach and steeper seat tube. Quote Have to wonder how much of these new crop of "high dollar budget" frames are just dumping loads of cash into presentation/marketing/website and are basically the same deal as other frames more in the 700-900 dollar range. As a Seka owner that's fairly active on the WW thread, I'm convinced you're paying for higher quality finishing kit, paint, warranty, and a genuinely better frame. Better doesn't mean perfect--I indeed am one of the people who suffered from the loose seatpost issue, as well as an unrelated frame-creaking issue that required warranty replacement. Take a look at Ribble, similar price-point, but there's a well-known WW thread documenting some pretty terrible quality issues. If you look at the competition there really aren't many/any options offering a 700g aero-optimized/tested standalone frame at this price point. My big concern is that the price point is getting so high that you might as well buy a domestic name-brand frame. Building up a Spear with Ultegra Di2 would run something like $6000-7000? You can get a new Cannondale S6E with Ultegra for less. I think Seka realizes this, which is why I believe Seka isn't pushing hard on selling in the western market. June 13, 2024, 12:10:32 PM |
1 |
|
Re: Seka Spear
I'd add Elilee Blize in there too which is around $1700 USD (judging off Australian prices) and 780g. They claim that it has been aero tested. There's also the XXE version at 680g and $2500 USD
June 13, 2024, 09:04:26 PM |
1 |
Re: Seka Spear
Can we make a list of these 700-800g +/- aero high dollar Chinese brand frames?Owner of the Agile here; below are the pictures of the actual weights of the fork, seatpost, and frame in size 51. I had YOELEO R12 previously, and the Agile is much more comfortable and "lively." A full video review is coming soon; the written one is already on my website. 
June 13, 2024, 11:42:29 PM |
1 |
|
Re: Hygge Aero Carbon Frame
3000 km update. I have no issues with frame stiffness, a flexy handlebar with 30mm Grand Prix 5000 S TR feels very good, especially on a bumps. I've hit some potholes and poorly constructed storm drains (well below the asphalt level) at high speed without any damage to the rims, handlebar, or frame, only get pain in my palms and wrists. The headset is also holding up well, with no play or marks on the steerer tube. The seatpost, tightened to 5 Nm, hasn't slipped at all. As for the ZTTO hybrid brakes, well, they work. They're slightly better than my old rim brakes with SwissStop FlashPro Yellow King and Elite ENT wheels. However i can't recommend them. The force that needs to be applied to the brake lever to stop almost the same as on the rim brakes, and pistons doesn't work evenly. One piston barely moves, and there's some flex in the lever arm that pushes the hydraulic cylinder. In my opinion, mechanical calipers like Avid BB5 or BB7 would be a better choice. The brakes also squeal at low speeds. I suspect this is due to the cheap pads (only $4 for two pairs). I've tried cleaning the rotors and pads, but the squealing persists. As a result, I've ordered Ashima ceramic pads, hoping they'll solve the problem. I swapped the crankset to a Shimano 105 because the ZTTO BB for a 30mm spindle started clicking after 1,000 km. Since I already had a Shimano BB and cranks, I decided to save money by not buying a new BB for the 30mm spindle. To shave off some weight, I replaced the 105 chainrings and bolts with Ultegra ones. This brought the total crankset weight down from 750g to 698g. Interestingly, the 105 and Ultegra cranks without chainrings weigh the same. Finally, I experienced some clicking noises from the rear axle. This happened when I switched the bike back and forth between a trainer and the rear wheel without properly cleaning the dropouts. Thankfully, a thorough cleaning solved the issue. I'm unsure if this is normal or not, as I never encountered it with quick-release skewers. June 14, 2024, 06:23:48 AM |
1 |
Re: Hygge Aero Carbon Frame
Do you think the brake performance is being hindered by the internal cable routing? No, I don't think internal routing significantly affects braking performance. As long as the pads haven't touched the disc, there's minimal resistance in the system. I use Jagwire KEB-SL brake housings. While they're definitely a pain to route due to their stiffness, they perform well overall. That being said, these hydraulic disc brakes with internal routing feel similar to rim brakes, but with much more bite. With my old rim brakes on carbon rims, it was difficult to stop effectively on steep downhills (-15% grade). I could feel the pads smearing on the rim, and applying more pressure on the lever wouldn't increase braking power beyond a certain point. This isn't an issue with the disc brakes. I suspect the ZTTO caliper's lever arm isn't very stiff. I can see some movement in the arm when I squeeze the brake lever after the pads make full contact with the rotor. Shifting also works flawlessly. In fact, I'd say the front derailleur performs even better than on my previous bike with the same groupset but semi-internal routing. This improvement is likely due to the full-length housing. June 14, 2024, 09:46:27 AM |
1 |