aikendrum’s FM015 build

A reader (Thanks aikendrum!) sent in the details and pictures of his matte-black FM015:
Upgrading from a flat road road bike (CRX1) I simply could not find a happy medium with factory built road bikes on the market – I wanted something fast light and within budget – the closest I came was the Felt AR4/F4.
After searching for carbon frames I stumbled upon the forums at roadbikereview.com there I made the discovery regarding Hong Fu – it took me quite some time to gain confidence in purchasing from a Chinese unbranded manufacturer however the more threads I read the more confident I became.

aikendrum's FM015

I settled on the FM-015 which appeared to fit the bill, SRAM force components and Ritchie accessories.
Final Build List is as follows;
1x HF-FM015 Carbon Frame (3K Black Matte Finish)
1 x HF-FK007 Carbon Fork to match FM015 frame
1 x HF-HB003 Carbon Drop Handlebars – Aero styling.
1x SRAM 2010 Force Groupset 175mm Crank, 11-23
1 x Hope Single Bolt Seat Post Clamp Black 34.9   —> to be replaced with 1 x Thomson Seat Collar Black 34.9
1 x Ritchey Pro Carbon Matrix 4-Axis 44 Oversized Stem Carbon 110mm
1 x Fizik MicroTex Bar Tape Black
1 x Ritchey Pro Carbon Seat Post Carbon (Red Logo) 300 x 31.6
1 x Ritchey Pro Biomax Saddle Black (Red Logo)
1 x SRAM S27AL Competition Clincher Wheelset Black SRAM Freehub
2 x Continental Grand Prix SuperSonic Road Tyre  700×23 (150g each!)
1 x Zefal Tyre Liners for MTB, Road and Hybrid Bikes Grey
2 x Continental Quality Road Inner Tube Presta 42mm 700×18-25
Pedals will be Speedplay Zeros.
Notes:
  • 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!
I have now put approx 1000km on my new Carbon HF bike and it’s a sweet ride – accelaration is awesome – the SRAM 27AL wheelset combined with light tyres make easy work of hills.
Overall weight is currently 7.4Kg without pedals – once I get the Speedplay zeros I expect it will fall into the 7.6Kg range.
(edit – seatpost collar was stated as 31.8, should have been 34.9)

3K or 12K Carbon?

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 carbon 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 and 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.

3K carbon fiber weave. It is impossible to weave 12K fiber as tightly as this because it will not flex into the tight circumferences required.

12K carbon eave close up

3K Carbon Weave close up

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.

FM001 Carbon Bike Frame

The FM001 was the original HongFu bike frame and is still available. It can be ordered in 3K, 12K or unidirectional carbon and I think it’s a very good looking frame (although I don’t like the fork in the picture below).

FM001 Frame Image

52cm geometry:

FM001 52 cm bike frame

54cm geometry:

FM001 54cm Frame Geometry

Sizing chart:

FM001 Sizing

Why buy a cheap carbon frame

I think the reason most people buy a cheap carbon frame from ebay or whereever is that they cost less than non-generic brands. Usually buyers have already owned a bike for a few years and are looking to upgrade and find the economics of saving 50% on the frame difficult to argue with.

Often that means being able to afford a groupset higher than they would otherwise (Ultegra instead of 105 is something that seems to be common) or the ability to purchase the exact parts they want (many would like to experiment with a SRAM build, but can’t find one in a bikeshop they like.)

One question many people ask when they discover carbon frames are available for under $400 is “are they safe”? I don’t think anyone can answer that in every case – it really is a case of buyer-beware.

There seems to be plenty of evidence that the well known generic frames (ie, the Hong-Fu/Greatkeen FM004, FM015 & FM028)  are no less reliable than any common brand. The RoadbikeReview.com forums have threads going back to 2008 about them with no cases of broken frames.

The other argument against them used to be that people thought they were just copies of generic frames. Fortunately it looks like this argument is dying out as people realize that – while some frames do have some superficial resemblance to other well known frames, they also have enough differences to make it impossible that they are copies. After all, many bike frames look pretty similar if you take the paint off.

At the moment it is increasingly common for people to find FM frames being house-branded by large bike shop chains or mail-order resellers. Ultimately, if you are concerned about the reliability of one of these frames that may be the best of both worlds for you.

FM028 Bike Frame Geometry

Here is the Hong Fu FM028 carbon bike frame geometry chart for 50cm, 52 cm, 54 cm and 56 cm frames. (Thanks to some readers for the 50cm, 52cm and 54 cm drawings. Does anyone have any other sizes? [email protected])

50cm:

52 cm:

FM028 52 cm frame

56 cm

FM028 56cm Frame Geometry

54 cm:

FM028 54cm Frame Geometry

I also found a sizing chart from an ebay listing that appears to be for the FM028:

size 500 520 540 560 580 600
seat tube 500 520 540 560 580 600
seatpost 200 200 200 200 200 200
top tube 521 534 543.1 560 573 586
seat angle 74.6 74.2 73.7 73.3 73 73.1
head angle 72.1 72.8 72.6 73.5 73.8 73.9
head tube 130 140 150 170 190 210
chain stay 410 410 410 410 410 410
fork length 367.8 367.8 367.8 367.8 367.8 367.8
wheel base 972.1 975.1 981.1 985.2 991.7 1003.4

Geometry for HongFu FM015

Here are the geometry charts for the HongFu FM015 bike frames, in the 53 cm, 55 cm & 58 cm sizes. (Update: A reader sent in the non-integrated seatpost drawing and a sizing chart. Thanks! Update 2: And now we have a 51cm drawing.)

51 cm:

FM015 51 cm bike frame with integrated seat post

53 cm:

FM015 53 cm frame geometry

55 cm:

FM015 55 cm frame geometry

55 cm (non integrated seatpost):

FM015 55cm frame (non-integrated seatpost)

58 cm:

FM015 58 cm frame geometry

Here is a sizing chart:

Sizing chart for FM015

Ebay Seller: anybaby8088

anybaby8088 is one of the better know ebay sellers of carbon fiber road frames. A number of people from the roadbikereview.com forums have purchased from them (him? her?) without problems. (Update: A reader has commented that anybaby8088 is the ebay account of Jenny from Hong-Fu, who most people deal with when buying bikes from the Hong-Fu website)

anybaby8088 usually has the Hong Fu FM004 and FM0015 frames for sale, but also has some other interesting frames.

This one is known as the FUll CARBON FIBER MONOCOQUE ROAD RACING BIKE FRAME, and is available in 3K or 12K weave.

Carbon Frame from seller anybaby8088

This carbon TT frame looks similar to the Hong Fu FM029 TT frame:

Carbon Fiber Timetrial frame from seller anybaby8088

Hong Fu FM004

The Hong Fu FM004 is an older (compared to the FM015) frame from Hong Fu. It remains popular because of its different fit and riding characteristics.

FM004 without Integrated Seatpost

FM004 with integrated seatpost