Hongfu FM079

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

gilles75 wrote:
Sun Mar 11, 2018 12:08 pm
Did you replace the Saevid Alien by the Lupina for weight reduction only, or for comfort reasons?
Neither. I had an open mold Toupe-like 143mm saddles on MTB/road bikes till recently. In 2016, I purchased an Alien for the road bike and did not notice any additional discomfort compared to the previous saddle, it was fine. Then last year I've bought a Darimo T1 for my MTB, but the open mold saddle was incompatible due to short rails, so I used an Alien instead. That left me without a saddle on the road bike, so I decided to try a 135mm Lupina, I always wanted something from Berk. Unfortunately, all of this happened almost before winter, so I did not have much rides on Lupina yet, but what I can remember was pretty much OK and the marginal weight saving (~10g) was a nice bonus. If I were you, I'd take my anecdote experience with a grain of salt, I am in no way an expert in saddle comparison.

gilles75
Posts: 13
Joined: Sun Mar 01, 2015 3:52 am

by gilles75

Klaster1 wrote:Bad news, the fork sits a tad too deep inside the head tube: with slack bearing preload it rotates freely, but after a bit of preload the fork crown rubs the cup slightly. All of this happens with a tall Neco lower bearing. The FSA ACB bearing I was planning to use has a stack lower by about 2mm, as things are now I won't be able to use it at all.
IMG_20180311_165442.jpg
I see at least two ways to solve the issue:
1. File down the bottom headset cup a bit. I'd rather not, also heavy bearing.
2. Make a bearing spacer. This way I can use FSA ACB too. The spacer should be ~3.2g if made from aluminium.

Any ideas about the spacer, did anyone try that, maybe there are similar products available?
headset bearing spacer.png
Your spacer solution looks like something that will work. 7075-T6 alum alloy would be very good for this application, but 6061-T6 is more widely available and is also very good.
I would make sure to use carbon assembly paste between the steer tube and stem and torque stem bolts to spec(4-5 Nm). I suspect that a spacer could make any lack of preload feel worse (allow more fork movements).
This fork weight is very good for a disk brake fork.

by Weenie


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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

As promised, here's the weight of BR-RS785 furniture to compare with RX4. The Shimano is lighter. I've also added the complete build list with scale shots of almost all components, except for those that require disassembly. Unfortunately, I've lost a bunch of older photos a while ago.
Attachments
IMG_20180312_204739.jpg
BR-RS785 furniture weight
IMG_20180310_131344.jpg
Hope RX4-SH furniture weight

joejack951
Posts: 451
Joined: Fri Feb 18, 2005 6:50 pm
Location: Wilmington, DE

by joejack951

Klaster1 wrote:
Sun Mar 11, 2018 8:37 am
Nice, the frame weights 982g, 60g less than my estimation and about 80g more than a 49cm from this thread. That includes FD/RD hangers and Shimano FD spacer plate. The headset cups and BB shell are bonded aluminium, there's a decent amount to save with BB30 and CF cups, I wonder if FM079F received these upgrades.
My 2016 FM079-F has a bonded aluminum BB30 shell. My size 50cm frame weighs 1060 grams including every piece of hardware shipped with it (water bottle cage bolts and all).

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

joejack951 wrote:
Sun Mar 18, 2018 3:32 am
My 2016 FM079-F has a bonded aluminum BB30 shell. My size 50cm frame weighs 1060 grams including every piece of hardware shipped with it (water bottle cage bolts and all).
Hey, this is yours, right? When I was looking for an example of an FM079 with crossed derailleur cables it came up, I plan to do the same too, kudos to @Calnago for the idea and motivational posts. Did you experience any issues with crossed cables, anything I should be aware of?

joejack951
Posts: 451
Joined: Fri Feb 18, 2005 6:50 pm
Location: Wilmington, DE

by joejack951

Klaster1 wrote:
Sun Mar 18, 2018 6:59 am
Hey, this is yours, right? When I was looking for an example of an FM079 with crossed derailleur cables it came up, I plan to do the same too, kudos to @Calnago for the idea and motivational posts. Did you experience any issues with crossed cables, anything I should be aware of?
Yup, that's my bike. I have not experienced any issues with using crossed cables. The only thing to be aware of is to not tangle the cables internally. Do a quick friction check before committing to the final run of the second cable you install. If you managed to loop one around the other it should be obvious and easy to correct at this point. Less so after you've fully routed and connected everything.

And while I'm all for giving credit when/where credit is due, my first road bike purchased in 2003 had crossed cables and I imagine many before it did, too. It allows for more generous derailleur housing bends and the added friction of the cables touching is insignificant (or at least offset and then some by the more generous housing bends). So while a good idea, Calnago's idea it is not :)

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

Still no progress regarding the shim, so I decided to do something else I wanted to try for a while.

First, I purchased a new rotary tool because my old one was unsafe to use and dremeled the Deda bar ends out:
IMG_20180310_165504.jpg
Deda Traforato stock bar end plugs
IMG_20180317_184954.jpg
Deda Traforato tuned bar end plugs
Then I decided that I don't really like the fact that a quarter of my Hylix bars are covered in red/white paint, so it had to go. This was my second time removing the paint from CF parts (I sanded damaged logos and scratches from SRAM S2200 before), but still scary. First I tried to rub the drops with a fine nail polish sponge, but it took so long that I picked the first suitable (or not :D) thing lying around - a sheet of 16-H sandpaper - and went mad with it. I guess it's good to remove the top layer of clear coat over paint, but afterwards it leaves deep scratches, so I stopped there. The rest was done with 200/400 sandpaper and the sponge from above. I'll try to clear coat the sanded parts later. As you can see, the coarse sandpaper removed everything down to the bare carbon with small patches of black paint left, while fine paper left most of black paint intact. On the drop, you can notice the layup seam.
IMG_20180318_162952.jpg
Stock Hylix Ergonova bars, 44cm
IMG_20180320_212732.jpg
Hylix bars after coarse sanding
IMG_20180327_213320.jpg
Sanded Hylix bars, center section
IMG_20180327_213342.jpg
Hylix bars, section initially sanded with coarse sandpaper
IMG_20180327_213400.jpg
Hylix bars, section initially sanded with fine sandpaper
IMG_20180327_213415.jpg
Hylix bars, sanded drops
IMG_20180327_213138.jpg
Hylix Ergonova weight after sanding

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Klaster_1
Posts: 419
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Location: Krasnoyarsk, Russia

by Klaster_1

The shims came in, but I guess the 2.5mm was a tad too much. When assembled, the distance between the cup and crown is about 2.4mm. I'll have to ask if 1.5mm or 1mm shim can be manufactured.
Attachments
IMG_20180402_185426.jpg
Lower headset bearing shim, 2.5mm
IMG_20180402_185541.jpg
FSA SL ACB bearing with a 2.5mm shim installed

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

Cut the fork today, the final weight is an amazing 303g, 12g less than my estimation. Too bad I left 2mm too much of a steerer, so I'd have to resort for a 2mm polished aluminium spacer for now and fix the issue later.
Attachments
IMG_20180408_101910.jpg
1.5mm headset spacer
IMG_20180408_124758.jpg
Workswell WCB-R-093 fork cut
IMG_20180408_132048.jpg
Headset cup to fork crown clearance
IMG_20180408_132756.jpg
Ugly spacer

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

Here's the frame with the Workswell WCB-R-093 fork and Hope RX4 brakes installed. The rear caliper had some minor clearance issues, the post mount tabs are oversprayed with clear coat and would benefit from proper surface facing, but a bit of file action was enough to solve some of the issues. I also put the post mount RX4 on the old Hongfu FK166 fork out of curiosity, clearance turned out to be tight too: the innermost part of caliper touches the fork leg area between PM tabs, if not for a slight recess on the caliper body it would not fit at all without 2cm PM adapter (i.e. 160mm rotor) or material removal.
Attachments
IMG_20180408_210928.jpg
Hongfu FM079 with Workswell WCB-R-093 fork, build in progress

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

The eeTop/eeNut was delivered today. Compared to J&L/MtZoom combo not much of a saving, but I like it more.

J&L nut:
+ Lightweight.
- Doesn't work with narrow steerers (mine was 22.3mm).
+ Works with narrow steerer using a custom wedge nut.
- Finicky to install, easy to drops into the fork.

MtZoom cap:
+ Lightweight.
- Laser engraved logos that are difficult to align with stem.
- Requires a deeper nut position.
+ Self-centering.

eeNut:
+ Lightweight.
- Spec claims a minimal supported steerer diameter of 22.8mm, so wouldn't fit into the FK-166 fork.
+ Doesn't drop into the steerer.
- Depends on a clean cut to center.
- Difficult to torque down, slips before biting down. I had to wedge the skirt with a hex key.

eeCap:
+ Cap separate from bolt, easy to align (but my cap did not have the slogan for some reason).
+ Lightweight.
+ Requires less distance to nut.

In addition, the FSA SL ACB bearing had disassembled when I was tweaking the headset preload without actual preload, probably my bad. The shield was easy to clip back in, maybe you can regrease the bearing this way?
Attachments
IMG_20180409_194741.jpg
Disassembled FSA SL ACB bearing.
IMG_20180409_190321.jpg
eeNut weight
IMG_20180409_190308.jpg
eeTop weight
IMG_20180311_151359.jpg
J&L steerer nut and a custom brass wedge
IMG_20180311_151328.jpg
Slightly tuned J&L nut weight
IMG_20180311_151229.jpg
J&L nut tuned to fit a narrow steerer

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

These Tune valves were bought last autumn, but I postponed installation until next year as the season was almost over. A solid ~15g weight loss, new valves are barely 1g heavier than shorter Barbieri valves that will go to another bike. Almost at the limit for 35mm rims, the pump head did attach and didn't leak during a quick test without a tire on.

On another note, the FSA bearings rotate the fork super smoothly, except for a sudden tendency to rotate towards one side without any load, even when fork is held vertically. I hope I didn't botch the setup by a shim and sudden bearing disassembly.
Attachments
IMG_20180410_202521.jpg
Gredes 60mm valves weight
IMG_20180408_184742.jpg
Tune 44mm valves weight
IMG_20180410_203158.jpg
Tune value fit in 35mm rim
IMG_20180408_175304.jpg
Barbieri tubeless valves

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themidge
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Location: yer ma

by themidge

Getting rid of those silly valve caps would save you another gram or two :wink: .

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

themidge wrote:
Tue Apr 10, 2018 5:13 pm
Getting rid of those silly valve caps would save you another gram or two :wink: .
Nah, the scales show a meager 0.23g per cap. I'd rather keep the stealthy look.

Today was the first time I used the Schwalbe Tire Booster bought along with the valves. The pump head's too deep for the amount of valves exposed, I had to unscrew valve cores in order to get some pressure in. The Booster did it's job just fine, so much unnecessary frustration saved! Beats taking the wheels to closest car service station, I was doing that for years and dreaded tire job every time.
Attachments
IMG_20180411_202400.jpg
Tune valves installed, with and without caps

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Klaster_1
Posts: 419
Joined: Mon Aug 15, 2016 10:25 am
Location: Krasnoyarsk, Russia

by Klaster_1

Some updates, I'm almost there:
- Front tire was the wrong side on, I had to pull it off and seat it again.
- Rear tire leaked at unacceptable level. First I decided to redo the tape, but the new tape cracked at the valve after I pushed hot screwdriver in too eagerly. Good thing I have more than enough of cheap Tesa 4289 tape. The second tape job went smooth and the tire sealed, still holding pressure after several days.
- I connected the brake hoses to levers and bled the Hopes. Nothing of the note, except that I did not face any issues like some people claimed in the RX4 thread. The Hope video does not mention that some pistons might get sticky on a new caliper, I had to encourage them out one by one.
- The shifting housing is complete. Rear cable was super frustrating to route through chainstay, I couldn't hook it from the RD side because the port seems to be either stuck or glued, I couldn't yank it out at all. After several frustrating hours, this was the solution: push another shifting cable from the RD side, when both cables hang from under the BB, connect both ends with heat shrink, pull everything back, remove the heat shrink.

Tomorrow I plan to setup the shifting. The dreaded FD-9000 has limited compatibility with FM079, I've attached a photo of frame area that interferes with FD. I think it effectively limits on how low the FD can sit, barring half of the available height.

And there's something special waiting for me in the post office.
Attachments
IMG_20180415_175744.jpg
IMG_20180415_212630.jpg

by Weenie


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