Chinertown
Chinese Carbon MTB => 29er => Topic started by: jpnovak on July 26, 2026, 09:32:02 PM
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Thanks for all the background info on this site. I am going to use this thread to document my Hongfu FM358 build. I am just a mid-50s x-racer that prefers pedaling efficiency over travel. Will be setting up with 100mm front and rear. Most of my local trails are pretty smooth and I am too old for the chunky stuff. i admit I prefer a steeper head tube angle and short chain stays so that i can change directions quickly and make line adjustments at speed. I learned on a rigid bike to ride around rocks and roots rather than over them.
The frame was ordered direct with custom paint. Took approximately 4 weeks to ship and about 12 days transit. Most of the parts are ebay specials picking up new take-offs where I could to keep budget down. A few used parts thrown in.
Build list of the major parts:
Frame FM358 Size L as prevoiusly outlined.
Fox 32 Step cast fork
Fox Float 3P rear shock
Serenade carbon wheels
Continental Dubinal 2.4 tires
Shimano XT 8100 12sp shifters, der and cassette 10-51 (cable driven)
Shimano XT brakes with 180mm rotors.
RaceFace Next R cranks and BB92 BB and 34T ring
shimano clipless pedals
Airwolf integrated carbon bar/stem and carbon seatpost (non-dropper)
Old broken in Flite saddle.
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Trying to attach pics.
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My background is materials chemistry. And my inner nerd came up with a decal scheme i call molecular camouflage. I used a cricut decal maker to put 72 lactic acid structures all over the frame.
As they say in racing... feel the burn.
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Love the decals, it's coming along well. :)
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Thanks. Yes, the build is coming along nicely. I think it is going to turn out well. I just hope I like the ride.
A few other items.
Rear shock mounting. the two pivot bushings on my Fox shock did not match the frame. The trunion side measured 22mm and the trunion was only 17mm opening. I machined down the pivot to match. The forward pivot side was 22mm and the opening on the frame was 30mm. So I had to make some 16mm OD, 8mm ID x 4mm thick spacers. I 3D printed them in P12-CF filament. Since the shock load is handled by the pivot bolt in the frame the spacers are non-load bearing. They just center the shock in the frame.
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Here is thr CAD model and installed spacers on the rear shock.
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First real snag. Its been more than 10 years since I have completed a build. There are now more "standards" in bike parts to match up.
I bought a set of XT 8100 2 piston brakes in advance of the frame arrival. It looks like I have the wrong setup for this frame. A few questions.
1. I think I have a post mount caliper. Can someone confirm?
2. I think I need a flat mount caliper. Seems like these are road/gravel type.
3. Looks like I need an XT 8110 caliper to mount to the frame
4. Do I also need an adapter for 180mm rotors? Or downgrade to 160mm?
Thanks in advance.
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looks like a flat mount and it seems you can't use an adapter (see google AI there are some links to reddit discussions).
therefore, you need to swap it with a native FM caliper i guess.
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Thank you. Will have to source a FM caliper.
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You need an FM to PM rear brake adapter
140mm (zero offset) for a 160mm rotor
160mm (+20mm offset) for a 180mm rotor
i'm using FM to PM 140mm adapter on this frame. For SRAM Motive brake and 160mm rotor
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TRP and others make flat to post mount adapters: https://trpcycling.com/products/flat-mount-to-post-mount?srsltid=AfmBOoo9mqAj7nApn49Gjg4Mk_GYHG_f4k_pXEU5vhifvArV1VW6SPDr
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Thank you for the link. I found a similar adapter. I ordered another flat mount XT caliper as a backup. Maybe one of these options will work.
Just getting one step closer to pedaling this thing.
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Nice decals. Good luck with your build. I’m also a happy rider with this frame!
For an 160mm disc rear you need a flat mount to post mount adapter.
On the front for a 180mm disc you problay also need an adapter.
I’m using two 4 piston brakes. Bought them at:
https://www.bike24.nl/producten/379981 (https://www.bike24.nl/producten/379981)
For the rear shock I bought these products: purchase two of these packages and use the widest bushings for the front.
RockShox Rear Shock Mounting Hardware 3-Piece 1/2" for Imperial &
Metric Shocks - 8mm - 8 x 30,0 mm. (2pcs)
The are delivered with assummetric size bushings.
For the rear side, you can use:
RockShox Rear Shock Mounting Hardware 3-Piece 1/2" for Imperial &
Metric Shocks - 8mm - 8 x 16.0 mm (1pc)
I use it with: ROCKSHOX SIDLUXE ULTIMATE 3P SOLO AIR REMOTE SHOCK 210x50.
First real snag. It’s been more than 10 years since I have completed a build. There are now more "standards" in bike parts to match up.
I bought a set of XT 8100 2 piston brakes in advance of the frame arrival. It looks like I have the wrong setup for this frame. A few questions.
1. I think I have a post mount caliper. Can someone confirm?
2. I think I need a flat mount caliper. Seems like these are road/gravel type.
3. Looks like I need an XT 8110 caliper to mount to the frame
4. Do I also need an adapter for 180mm rotors? Or downgrade to 160mm?
Thanks in advance.
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Its finally starting to look like a real bike.
I cant install the BB/cranks until I confirm if my brake adapter works. If not I will have to pull a new hose through to swap calipers. Why Shimano uses a 90 deg banjo fitting on PM calipers amd straight hose on FM calipers inwill never know.
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Moving along. I managed to find feint and rear brake adapters that work. The front is a +20 standard piston mount for the 160mm rotors. I did have to trim down the front mounting bokts because they bottomed out on my fork. The rear is FM to PM +20 adapter.
This means I do not have to change the rear caliper nor pull another brake hose through the frame.
Bottom bracket and crank install will be next.
Hopefully will get Maiden voyage this weekend.
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Moving along. I managed to find feint and rear brake adapters that work. The front is a +20 standard piston mount for the 160mm rotors. I did have to trim down the front mounting bokts because they bottomed out on my fork. The rear is FM to PM +20 adapter.
This means I do not have to change the rear caliper nor pull another brake hose through the frame.
Bottom bracket and crank install will be next.
Hopefully will get Maiden voyage this weekend.
You installed the front adapter wrong no? Usually the arrow points up
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You installed the front adapter wrong no? Usually the arrow points up
Good catch. Yes. Pic was initial mock up. Was inverted and fit.mich better. :o
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wow very nice!
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New bike psyche. It's finally on 2 wheels.. ride around the block went well. Fit is good. Bars too low. Its Liigghhhtt. Need to weigh. Guessing 22lb range. Will weigh at some point.
Will get some ride and feedback this week.
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It looks fantastic. Great job. :)
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Well, 3 weeks of work travel and I have no ride report yet.
The only update is related to rear brakes. They squealed horribly and had no grip at all. Possible that I may have gotten a little mineral oil in them when bleeding. No amount of cleaning wpuld work. So last night I baked out rotor and pads with a propane torch. And then filed a chamfer in the leading edge of the pads. Finally seem to be quiet. Hopefully this weekend will be real Maiden voyage.
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Had first ride on new bike this morning. Nothing broke or came loose.
Almost no suspension bob when pedaling hard. Can feel bike absorb bumps without pedal kickback or other weird artifacts. Climbing traction is amazing.
I don't like the front end. I am just not used to modern slack head angles. Front wheel Feels so far in front. Hoping I get used to the lead then follow feeling of the front wheel. To me it is less direct, almost Slow and floppy in really slow (almost track stand) rock gardens and tech stuff
Fox shocks are way more supple than Rockshox.
On flowy trails it feels stiff and fast. So.far I am really pleased with performance. .
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I changed the stem angle to raise the bars and moved the seat slightly forward to put more weight on front end. That made a huge difference in weight balance and handling.
I really like this bike. It's fast. Climbs very well - much better than I expected.
Certainly I would recommend to anyone looking for light weight XCO frame this should be on the list.