Kai kindly sent in his completed bike: a FM015 built with what looks to be SRAM Rival, and great paintwork.
A reader (thanks Graham!) was kind enough to email me a spreadsheet he’d been working on cataloging all the unbranded carbon bike frame sellers, their AliBaba and Ebay stores and what frames they sell.
Obviously this is a big job, so I’ve turned it into a Google spreadsheet so that everyone can add their knowledge.
Please add everything you know about each seller. If there is something you aren’t sure about or (you think you broke the spreadsheet ) drop me an email and I’ll try and fix it: [email protected]
To edit it go here, or just view it below:
Thanks to a kind reader, I’ve been able to post new geometry diagrams for the following frames:
If you have any further diagrams (for these or other frames) I’d love to hear from you. Pics of your built up bikes (and details of the builds) would be great too: [email protected]
Has anyone build one of the mountain bike or TT frames? I seem to see a lot less of them.
A reader sent in the drawing for a 57cm FM006 frame (thanks!). If you have any other sizes, please send them in ([email protected])
Chain Reaction Cycles currently has a clearence on Vitus frames
with some pretty good discounts (over 80% in some cases).
Most of their frames are alloy, but both the Zenium VR and (I think) theÂ Zenium R‘sÂ have carbon seat stays (which is one of the more effective ways to get the vibration absorbion of carbon).
It’s the prices that make these worth looking at though. The Zenium R
is priced from $149 (+$23 shipping to the US), andÂ the Zenium VR is from $170. Those prices are pretty competitive with anything you’ll find on ebay, and in this case you getÂ a well known reseller backing it up.
I really like the look of the Zenium VR frameset, too.
Given that it’s pretty hard to walk into most bike shops and try out a HongFu bike frame (ignoring the many bike shops selling them as their own brand for the moment) it seemed useful to try and help out with sizing the frames as much as possible.
One recent innovation in sizing frames has been using Stack and Reach measurements because these can easily be compared across frames and sizes.
Most geometry charts still don’t come with Stack and Reach measurements yet, so I’ve created a calculator, preloaded with the FM015 & FM028 geometry.
Try it out now and let me know what you think: Frame Size Calculator
Discuss this at the new Bike Sizing Forum.
- The “SRAM GXP Bottom Bracket Cup Set English Thread” which comes as part of the SRAM Force Groupset is as soft as butter (for want of another word!) be super careful when applying torque to the cup ensuring your wrench does not slip off causing cosmetic damage in the least or mechanical in the worst case. I had this issue and even though it didn’t affect the performance I replaced it with a new Cup Set ~ AUD$29.13 from Wiggle
- Hongfu sell a Seatpost (1 xHF-SP003 $38.00) – it appears their is no adjustment for the pitch – mine was pitched at about 5-10deg to the horizontal – no good I simply could not use it – no great loss at US$38 but just be warned.
- The HF-SPC001 seat post clamp works well but is heavy and can be opened by hand – I initially replaced this with a Hope clamp as above however this is made of a very weak aluminium and I ended up splitting the bolt – Hope sent me a replacement no questions asked and I am currently using it but would like to replace it with the more robust Thomson Seat Collar.
- I used the Neco headset from Hongfu, so far so good – I didn’t have too many issues installing it but used a different technique (Not PVC) for installing the race onto the fork. I used a plank of wood – drilled a 2-3inch hole, supported the plank of wood between two chairs, placed the race onto the fork and banged the race down onto the fork through the hole as opposed to the PVC method where you may be putting excess pressure on the fork and will have to support he fork somehow. (comprendez vous?)
- My frame did not come with any cable barrel adjusters – I purchased these from my LBS.
- No issue with the FM015 Top tube internal cabling however I found the SRAM rubber gromits used between the end of the gear/brake cable and top cap made the brake/grear change spongy – I ended up not installing these – I will have to be vigilant of water ingress but so far so good
- Underneath the BB there is a plastic gear guide – this was screwed into place with a factory screw and didn’t look very durable – I replaced this with a decent Stainless Steel screw for good measure.
- The 3K black Matte finish is better than I expected – it’s actually a paint finish ontop of the raw carbon so water et al beads off without worry. I have protected the underside of the down tube with psuedo 3M Helicopter tape – stones flicking off the front tyre made quite a noise however produced no noticable marks – the 3M tape is just for insurance!
Most cheap carbon bike frames come in both 3K or 12K versions. Many people ask which is best.
Firstly, what is the difference between the two types?
Carbon fiber is made of thin carbon “threads”, each of which is made from even smaller carbonÂ filaments. 3K or 12K refers to the number of filaments per thread – ie, 3ooo or 12ooo filaments per-thread.
Originally, most carbon fiber was woven using 3K fiber. During the early to mid 2000′s, though raw carbon fiber increased in price as more and more of it was consumed in military and aerospace applications.
New carbon fiber manufactures developed processes to use 12K fiber instead of 3K. This new fiber could be manufactured cheaper, but had the disadvantage of being more difficult to handle andÂ mold, especially on tight circumferences
as well as being not as strong as 3K filaments. For example, cstsales.com lists the strength of 3K fiber at 7400 ft/lb while 12K is listed at 1800 ft/lb. (Edit – it has been pointed out that these measurements are actually for weight per length, not strength at all. Doh!)
Now, most handling problems have been overcome and for bicycle frames the molding problems are not an issue. The finish on the frames looks different though, because 12K filaments cannot be woven as tightly as 3K fiber.
Unfortunately, for most bike frames it can be difficult to know how much of the frame is manufactured from each type of carbon fiber. Carbon fiber frames are manufactured by laying down layers of fiber weave with resin, and we can only see the outer, cosmetic layer. Without destructive testing and/or a forensic investigation of a cut up frame it’s impossible to know what (if any) effect weave has on a frame’s riding characteristics.
In conclusion, you are probably best off buying the type you like the look of, or whatever is available.
Update: I found this document from hexcel which lists the strength of various fiber type. It gives some useful information, but really shows how the exact grade of fiber used has a much bigger effect than if it is 3K or 12K.
The FM027 (aka TP-R813) Â is one of the newer frames available. I haven’t seen any built up yet, but judging from the curves in the seatstays it should be a pretty comfortable bike to ride.
55 cm Frame Geometry: