Question: why the angled stem and not go up a size? Is it handling, looks,...?

I think I explained a bit in an earlier post, but the main reason is that I want the top tube to be as low as possible because my knees/inner thighs often rub it. I chose this frame because the size 535 has a reasonably low top tube, yet still has a front-center that would typically be found on a 58cm+ (606mm), which is kinda important at my height for descending stability, and also ensures no toe overlap due to my forward cleat position.
Second, it gives me more options -- I can flip the stem easily for a 1hr crit and get an aggressive position. But for anything longer, I think the higher position is faster, especially on climbs (see: arnepeters95 on instagram, I agree with everything he says).
Third, there's a bit more aero potential in theory -- kinda like what the simplon pride ii, cervelo s5, colnago y1rs, bianchi oltre rc, and all tt/tri bikes are doing. Because a head tube is always going to be wider than a stem since it contains the steerer/bearings/cables -- so why not replace that frame stack with stem stack? Of course, a round +17deg stem isn't very aero either, so eventually I want to surround the whole thing with a printed fairing, which should improve the looks as well.

Received my SC-R55D a few days ago. Almost 2 months from the order to receiving it at my door. Shipping was only a few days (Fedex International Priority).

Size 535 (more like a 56-58cm).

This is my first carbon bike, I'm not sure what's normal and what isn't.

NOTE I specifically requested it to be unpainted. So, naturally it looks rougher than one you might receive with the standard matte clear coat. Don't judge it too much based on the unfinished appearance. I'll disassemble and paint it in the spring.

Photos (82)
https://imgur.com/a/tJCYRZ4

BB Shell
I measured the BB with a bore gauge, 6 measurements per side and averaged.
DS: 40.97mm
NDS: 41.02mm
Could be better, could be (far) worse, I think the ideal is like 40.98mm-41.00mm.
DS should be fine, NDS I might use a bit of Loctite 641 for good measure, but will see how it feels first.

Weights

Part	Weight (g)	Notes
Frame (size 535)	842.1	Unpainted; completely bare (without hanger, FD tab, seatpost wedge clamp, etc)
Fork	393.3	Unpainted; steerer is 300mm
Seatpost (1-bolt setback)	177.2	Matte paint, with hardware; 40mm length
Seatpost (2-bolt zero-setback)	171.2	Matte paint, with hardware; 400mm length
Seatpost wedge clamp	15.5
Seatpost Di2 battery wedge clamp	7.4
Seatpost rubber cover	4.7
FD tab + mounting screws	15.5
Derailleur hanger (UDH)	27.9	Not SRAM-branded
Expander plug	54.8
Headset top cover	15.5	Not FSA-branded; ~10mm height
Headset bearings	61.2	51.8 x 40 x 8 mm, 36 x 45 deg
Headset spacer (5mm, each)	5.7	comes with 5x
Headset compression ring	6.9
Bottle cage bolt (each)	2.8	comes with 5x
Bottle cage washer (each)	0.3
All cable port plugs (5x)	1.8

Frame + essential small parts (hanger, FD tab, seatpost clamp, rubber cover): 905.7g

I didn't purchase the offered thru-axles, getting some blue ones from elsewhere.

Notes/Issues

• It was packed well
• Carbon looks pretty good on the inside. I assume EPS molded. No large wrinkles
• Brake mounts look good
• Seatpost slides into the frame easily, certainly not too tight, perhaps could be a bit more snug if anything
• Geometry of the frame seems accurate. The fork length however is ~4mm longer than stated (measures in at 374mm)
• Headset bearing seats look good
• Seems to be compatible with mechanical shifting? There's an exit hole behind the ST (in addition to the FD Di2 wire exit hole)
• The seatpost wedge clamp is definitely better finished than the one shown in Peak Torque's Tavelo Arow review (sides are nicely rounded), but could probably still use a couple minutes of sanding to make the top edge smoother where it contacts the post.
• The pocket that the clamp sits in is angled, so it falls right into the seat tube when removing the seatpost. And it's not easy to hold it in place with your finger either, again due to the angle on the bottom.
• The rubber cover for the seatpost clamp touches the grub screw in the clamp which prevents it from sitting flat on the top tube. Also, it fits kinda loose, not sure if that's common, but I assume it will jump around a bit on rough roads, or even in the wind.
• HT/headset/fork vertical gap is about 1mm on both the top and bottom, which is noticeable from the front and sides. Weatherproofing is poor. Not sure how much of the gap is due to the bearing inset vs. the non-FSA ACR top cover. Might be better with a real FSA cover?
• Lower headset bearing sits kinda high on the bearing seat. But probably fine.
• Cable routing -- there's a guide tube in the NDS chainstay going to the rear brake. And the fork of course. But I don't see anything for the rear derailleur. And it didn't come with a foam sheath to prevent rattling in the DT.
• The DT water bottle could have been placed lower for aero I think. There's a few cm between the two.
• The threads in the fork dropout are kinda rough, one of the first threads is clearly a bit damaged, and there seems to be some excess resin that made its way to the bottom of the threads. I tried threading in a 1.5 pitch thru-axle and it felt quite rough. Ordered a rethreading tap to chase the threads, let's see if that works.
• The additional zero-setback seatpost I purchased has a 2-bolt clamp rather than the 1-bolt Ritchey-style clamp on the setback post. So anyone worried about the 1-bolt clamp slipping might consider the zero-setback seatpost, if your fit allows it.
• Tire clearance -- fork can fit some larger tires for sure. Width between the fork legs is around 50mm, not sure about radial clearance. Wouldn't be surprised if it could fit a 38-40mm tire leaving 5mm around. On the frame, width between the chainstays is ~40mm, so personally I wouldn't use anything wider than 32mm actual.
• Rear flat mount bosses are 20.8mm tall, for those looking to buy the correct length bolts.
• Wish I had thought to order an extra seatpost clamp in case I lose it.

Aero
Random dimensions for unscientific aero weenie comparisons:

• Seatpost is ~21.8 x 33.4mm. Wider than supersix (15mm)/sl8/etc
• Fork legs are ~16.5 x 40mm in the middle. Slightly narrower than supersix
• DT is 43 x 63mm in the middle. Narrower than supersix
• HT is 45 x 73mm in the middle

As I might've mentioned earlier, I'm doing a weird setup with a +17 deg stem to approximate the simplon/cervelo/bianchi/colnago thing and to get enough stack for my tall self. Then I'll design a fairing that encloses the stem/spacers/cables to make it sleeker and more aero. Hoping to finish it up by mid-January and have it ready for spring racing.

It is the same photo that speeder uses on their website for the SC-R55D.

Adapt calls it the FM55 (see: three more 3D renderings). Looks identical except Adapt says theirs has T47, which I don't think is possible without an entirely different frame mold, considering it's bigger than BB86. Or it's just a listing error.

Follow the instructions for the Hope RX4+ flat mount mineral oil. They're almost identical.



(note: youtube embed not working, just search "Hope Technology: How to Bleed RX4 Shimano Calipers / Brakes" on youtube)

https://www.hopetech.com/webtop/modules/_repository/1/documents/RX4Instructions_Min_EN_FR_DE.pdf

Both the ZRace XG and Hope RX4+ have the bleed port near the top of the caliper, which isn't as good as Shimano's "One Way Bleeding" with the bleed port at the bottom. But it should still be completely possible to get them to the same level, just with a bit more effort. Follow all the tips the Hope mechanic mentions.

Just put in an order for the SC-R55D after a dozen emails with questions and requests Communication with Justin is always smooth and he usually replies within a day (if not an hour or two), though I feel bad about bothering him for a single frame.

I think this frameset looks really good. Similar to the Tavelo Arow, but some differences in shaping (look at the TT-HT junction), plus this frameset has SRAM UDH, a round steerer (much preferred from a safety perspective), concealed dropout holes. Compared to the older SC-R52D model, I think the fork crown and seatstay junction shaping is much better, as well as the deeper-profile fork legs.

I'm buying this frame for the aero upgrade -- I won a few cat 3 road races this year on a heavy round-tube aluminum gravel frame, but it will be harder to continue with it at the Pro/1/2 level. Aero-wise, I think the SC-R55D is probably decent enough. Looking through the Tour Magazine wind tunnel tests, the similar Wilier Filante SLR tests around 210w @ 45kph with Zipp 404 wheels. For comparison, the fastest road bike is the Simplon Pride II, basically a TT frame, and it's at 202w with the same wheels. Supersix Gen 4 and SL7/SL8 are somewhere in between the two. Comparing the SC-R55D to the Filante, the fork legs are deeper, the seatpost appears narrower, the seatstays attach lower, and the fork-HT transition looks more modern. So aero performance is probably on par with the SL8, at the cost of 100g or whatever, which I don't care about.

I was actually planning on buying a Supersix Gen 4, but after trying out a 58cm model, my thighs rub against the top tube. And I think this is a problem I will have with most aero bikes with wide, high top tubes. I could size down, but then that decreases the front-center too much, which isn't ideal for handling at my height. So I settled on the SC-R55D size 535, which has a lower top tube, and front-center almost identical to the Supersix 58cm at 606mm. The downside there is that the stack is pretty low, so I might need to use a number of spacers, but I'm thinking of using an up-angled stem instead (i.e. the Simplon Pride / Cervelo S5 / TT bike strategy).

The only real downside is BB86. Not ideal for DUB of course. I'll be measuring it with a bore mic. Worst case, buy a 40.98mm reamer ($150) and/or BBInfinite bottom bracket ($200) and it's still a good deal I think.

Oh and the shaping of FSA ACR spacers is slightly annoying. Spacers are on the leading edge of the bike and it seems like low-hanging aero fruit to make it airfoil shaped like the SL7/SL8 rather than a rounded rectangle. I'll either try to print something, or maybe try using a Deda DCR upper headset instead, as the shaping is a bit better.

Unfortunately, custom paint isn't available for a single frame. So I'm getting it RTP (ready-to-paint). Going to do spray.bike, which might be a pain in the cold of ~November, but I'll figure something out.

Prices (USD): $660 frameset (including seatpost), $30 headset, $20 thru-axles, $50 additional zero-offset seatpost, $172 shipping + paypal

Thru-axle dimensions:
Frame 164mm M12*P1.0*L18
Fork 120mm M12*P1.5*L12

While a steel bike frameset will probably never be as aero as a carbon one, I think the fork is probably a big part of the aero frameset equation, being on the leading edge, so why not try to maximize the aero-ness of a carbon fork on a steel bike?

I'm looking for:
- minimal fork leg thickness
- aero cross section (airfoil/kammtail, not a plain oval)
- minimal fork crown
- No "lip" behind the fork crown designed to mesh with the frame, should be round-ish like the SL7 (or at most a small lip)
- supports 32mm tires
- internal routing from steerer

I'm assuming most manufacturers will allow me to buy just the fork from a frameset, but I'm not actually sure that's true.

Ideally I would just get an Aeroad CFR or SL7 fork as those frames test quite well in the wind tunnel and have minimal/round-ish crowns, though obviously you can't just buy those.

Options I'm considering:
- Workswell WCB-R-306 / WCB-R-309 (not sure they would sell me one)
- Carbonda/Flybike FM1056
- Carbonda/Flybike FM1136
- Dengfu R12
- Elves Falath Evo
- Ican/Triaero A22
- Speeder SC-R52D
- Velobuild VB-R-168
- Yoeleo R11

If anyone has any measurements on fork blade thickness/depth, I would love to know. It's pretty hard to tell based on photos.

If anyone else can think of any other options, I'd love to know.

Thanks!