These are Hycline’s listed values. They show Hycline positions Code: Bones as a hybrid all-terrain design (balance of street and off-road), while Rock Conqueror is the chunkier, heavy-duty off-road tire. The weight and physical tread geometry numbers already tell us a lot about how each will behave in winter conditions.

Construction and tread design: why geometry matters in winter

Code: Bones — what the tread and build promise

Hycline describes Code: Bones as featuring a symmetrical dual center tread with wide, sloping blocky knobs and extended side tread for cornering bite. The marketing emphasizes lower rolling resistance on hardpack/pavement, and “bone” pattern knobs that cut through loose terrain while still feeling nimble in the city. Code: Bones unit weights are lighter than Rock Conqueror, and Hycline rates its speed and control at around 3/5 and 4/5 respectively on the product page—marketing shorthand for “fast enough, pretty controllable.” 

From a technical perspective, that combination (center area with tighter, shallower knobs and more prominent, aggressive side knobs) is exactly what you want if you need:

• lower rolling resistance on packed snow or groomed winter trails, and

• lateral bite for carving out of a soft berm or negotiating packed snow turns.

The 30 TPI indicates a medium casing flexibility — not ultra-light race casing, but not a heavy, super-burly casing either. That’s consistent with a tire meant to balance comfort, traction and weight. The stated max pressure (40 PSI) is high compared to typical winter fat-bike practice (riders often drop much lower in deep snow), but useful as a ceiling for pavement or heavier riders.

(Code: Bones Tread)

Rock Conqueror — heavy knobs, heavy duty

The Rock Conqueror page leans into the “muscle” metaphor: large convex buttons—essentially huge, closely spaced square knobs that bite into loose rock, mud and deep snow. The tire is heavier (2.5–2.8 kg per unit) and explicitly marketed as thicker, more wear-resistant rubber with “enhanced thickness and tread quality” for puncture resistance and load capacity. Hycline’s own copy positions this tire for rock, forest, mud and snow.

Large, widely protruding knobs displace snow well and give excellent traction in loose, soft snow because they can dig and find purchase. The trade-offs are visible: on hardpack or pavement this design increases rolling resistance, can be noisy or vibratory, and reduces top-end speed—exactly what several reviewers on the product pages have said (good in sand/gravel but chunkier on pavement). 

(Rock Conqueror tread)

Realistic winter surface matrix — expectations, and what matters most

Below I evaluate how each tire will perform across distinct winter surfaces. For each surface I give (A) a short summary, (B) expected performance rating (1–10), (C) explanation rooted in tread and spec, and (D) practical PSI guidance. Ratings and guidance are inferred technical assessments based on documented specs and customer feedback on the product pages, not on an in-person test rig. I explicitly label that inference.

Note: In winter fat-bike work, tire pressure, rider technique, and drivetrain gearing are often just as important as the tread. Low pressures increase float through deep snow; arguably the single biggest lever a winter rider has.

1) Deep, unconsolidated snow (powder)

• Code: Bones — Expected rating: 6/10.
  Why: The Code: Bones has blocky knobs and a broader contact patch than a skinny mountain tire, so it will float better than narrow tyres. However, the knobs are not oversized; the pattern is tuned for mixed terrain, so float is moderate rather than exceptional. For very deep powder, you’ll want extremely low pressures and/or a wider footprint than 4.0 if possible. (Inference from tread geometry & marketing.) 
  PSI: 4–8 PSI (very low; depends on rim and tubeless setup).

• Rock Conqueror — Expected rating: 8.5/10.
  Why: Oversized convex knobs and heavier casing displace more snow and provide real bite to dig and push. The large buttons act like paddles in powder; combined with lower pressures, Rock Conqueror will feel much more capable in deep, unconsolidated snow. Expect a heavier rotation but better float and traction. (Inference from tread and Hycline copy.) 

2) Packed/firm snow (groomed trails)

• Code: Bones — 8/10.
  Why: The dual center tread and lower rolling resistance promise good speed and stability on packed snow. The pattern locks on to the firm surface while still offering lateral bite for turns. This is Code: Bones’ sweet spot: mixed surfaces where you need forward speed on packed sections but occasional soft patches. 
  PSI: 6–12 PSI.

• Rock Conqueror — 6/10.
  Why: The bulky knobs can become less efficient on packed snow; they do bite, but they also add rolling drag. On groomed, firm winter trails you will notice lower momentum, especially on longer flat sections. However, in technical packed trail with rocks and rutted features, the Rock Conqueror still pulls ahead thanks to the heavy knobs. 
  PSI: 6–12 PSI (lower for slippery packed ice).

3) Hard ice and glazed surfaces

• Code: Bones — 4/10 (without studs).
  Why: Neither tire is studded from factory; on pure ice, even aggressive tread only helps so much. Code: Bones’ multiple lateral bite edges provide marginally better braking and corner grip than a slick, but it will slip on polished ice. If you frequently face ice sheets, studded tires or studded inserts are required. Hycline’s pages do not list studs as stock features. 
  PSI: 8–15 PSI (higher to reduce knob squirm).

• Rock Conqueror — 5/10 (without studs).
  Why: Slightly better than Code: Bones because the large knobs can claw into cracked ice or frost, but again, studs are the only reliable solution for continuous hard ice. For occasional glazed patches, Rock Conqueror’s bigger knobs will feel more confidence-inspiring but still slip risk remains. 

4) Slushy/wet snow & slop

• Code: Bones — 6.5/10.
  Why: The center-to-side knob distribution sheds some slushy material and keeps a predictable contact patch. Doesn’t excel at mud-like slop but remains rollable and controllable. 
  PSI: 8–14 PSI.

• Rock Conqueror — 8/10.
  Why: The aggressive tread will evacuate slush and provide better bite into damp snow; it essentially behaves like a mud tire in slush due to knob geometry and spacing. Expect more spray and drag but better forward progress. 

5) Mixed urban winter (pavement, salt, compacted sidewalk snow)

• Code: Bones — 8.5/10.
  Why: This is the best all-rounder for commuting: lower rolling resistance and nimble handling make Code: Bones superior for mixed city winter riding. The extended side knobs increase cornering safety on partially snowy turns. Hycline markets it explicitly as balancing off-road and city riding. 
  PSI: 20–35 PSI on pavement depending on comfort.

• Rock Conqueror — 5.5/10.
  Why: Usable, but it will feel noisy, heavy and slower on pavement. Reviewers in the product page note vibration and reduced speed on streets, confirming this tradeoff. If your ride is primarily paved with occasional winter trail detours, Rock Conqueror might feel overkill. 

6) Rocky, technical winter singletrack

• Code: Bones — 7/10.
  Why: The blocky side knobs give cornering control and adequate bite on mixed rock; the lighter weight helps maneuverability. Not quite as puncture-resistant as Rock Conqueror though. 

• Rock Conqueror — 9/10.
  Why: The Rock Conqueror is built for rocks: oversized convex knobs absorb impacts, bite into uneven surfaces, and the thicker casing resists cuts. If your winter includes many exposed rocks or rooty ledges, Rock Conqueror is likely the safer choice. Reviewer comments align with this—users praise its off-road capability and puncture resistance. 

Rolling resistance, speed and energy cost

• Code: Bones is marketed with “minimal drag on hardpack or paved terrain” and rated higher on speed in Hycline’s page; its lighter unit weight (2.05 / 2.74 kg) and tighter center tread translate to lower rolling resistance compared to Rock Conqueror. That means for long winter commutes on packed snow or cleared roads, you’ll expend less energy and maintain higher average speeds. 

• Rock Conqueror will cost you speed; Hycline and reviewers explicitly note chunkier ride and noise on pavement. The heavier weight increases rotational inertia, making acceleration slower. That trade is acceptable for riders who prioritize traction and puncture resistance over speed. 

Quantitatively, an exact watts/km penalty depends on rider weight, pressure, temperatures and trail condition. But as an approximate rule of thumb (derived from typical tire engineering — inference), expect Rock Conqueror to add 5–15% energy cost on firm surfaces vs. Code: Bones’ more efficient center tread.

Puncture resistance, casing and load capacity

Both models list:

• Max load 266.6 lbs (120 kg)

• 30 TPI casing

• Puncture-resistant marketing copy and heavier rubber for Rock Conqueror. 

Interpretation:

• 30 TPI is moderate — not ultra-light racing but not fortress-like either. High TPI often improves ride suppleness; low TPI indicates more puncture-resistant but heavier casing. Hycline’s 30 TPI and Rock Conqueror’s thicker rubber combine to make Rock Conqueror noticeably tougher. Code: Bones claims “high-density rubber with strong puncture resistance,” which aligns with a medium-duty casing optimized for commuting and mixed terrain. 

If you carry heavy loads (cargo, e-bike battery) or ride over sharp winter debris (salt-cut metal, shards, hidden rocks), Rock Conqueror’s build is the safer bet.

Weight & rotational mass: practical implications

• Code: Bones: 2.05 kg (20×4) and 2.74 kg (26×4).

• Rock Conqueror: 2.5 kg / 2.8 kg for similar sizes. 

That 400–500 g per tire difference at the rim is significant: rotational weight hits acceleration and hill climbing disproportionately. For riders doing long winter commutes with climbs and wanting nimbleness, Code: Bones is the better compromise. For riders whose priority is grip in technical or deep conditions, that weight penalty is acceptable.

Tubes, valves, and practical installation notes

Both product pages offer the tires sold as single tires or with tubes. Rock Conqueror product page lists Schrader valve tube size and valve length (Schrader 32 mm) in one part of the description; Code: Bones offers general tubeless/clincher options but specifics vary by selection. If you run tubeless at low PSI (which is common for winter fat bikes), confirm bead compatibility and have proper sealant — colder temps can increase sealant viscosity and reduce sealing speed, so refresh sealant before the season. 

Customer feedback synthesis (what real riders said on the pages)

Both product pages include customer reviews; while limited in number, they reveal useful themes:

• Code: Bones: Users reported quick shipping, positive first miles, and a general appreciation for the balance between city use and off-road. One reviewer cautioned about gravel handling, indicating you need balance skills on loose gravel. Hycline’s product page shows overall favorable sentiment and a control/puncture resistance rating around 4/5.

• Rock Conqueror: Several reviewers highlight its off-road prowess and puncture resistance but also mention the heavier, chunkier feel on pavement and some vibration/noise—consistent with Hycline’s own marketing. One reviewer said it “rides like butter” on sand/gravel, losing 1–2 mph on an e-bike but holding well in turns. Another user said they wished for a lighter alternative, confirming the weight tradeoff. 

I count these reviewer themes as corroborating evidence: Hycline’s marketing claims line up with owner experience — Code: Bones is all-terrain nimble; Rock Conqueror is off-road dominant and heavier.

A practical winter test protocol (how I would test them in the field)

Below is a reproducible test plan any rider or shop reviewer can follow to benchmark the two tires on winter roads. If you want, I can draft this into a one-page lab sheet to use on future test days.

Test bike & setup

• Same fat-bike frame, same wheelset (to isolate tire effect), same e-bike assistance level or same rider power output.

• Inflate to target PSI for each surface (document exact pressure). Use tubeless with 60 ml of sealant per tire for reliability. Ride with the same load and gear ratio. Measure tire circumferences for speed correction.

Test surfaces

1. Cleared pavement (1 km loop) — measure average speed & wattage (if power meter available).

2. Packed snow trail (2 km) — time/speed & perceived grip in turns.

3. Deep powder section (500 m) — measure time to climb a short slope and track rider perceived float.

4. Icy patch simulation (controlled 100 m) — note slip events (requires safety).

5. Rocky technical section — count punctures, note confidence in line holding.

Metrics

• Average speed (for non-e-assisted riders use power meters)

• Heart-rate / watts to hold pace (if possible)

• Number of slip events / recoveries

• Rider-reported comfort (1–10) and vibration (1–10)

• Puncture incidents

• Subjective cornering confidence

Notes on winter testing: Repeat tests at multiple PSI settings (e.g., 6 PSI, 10 PSI, 18 PSI) to show how pressure interacts with tread. That’s critical in winter.

Who should buy which tire?

Buy Code: Bones if:

• You want a single winter tire that handles both snowy trails and city commutes.

• You value lower rotational weight and lower rolling resistance on packed surfaces.

• Your everyday ride includes pavement, plowed bike lanes, or groomed multi-use paths.

• You run a mixed riding schedule and want easier acceleration and less vibration on hard surfaces. 

Buy Rock Conqueror if:

• Your winter environment is dominated by deep snow, sand, rutty trails, exposed rock and mud.

• You prioritize puncture resistance and maximum bite over speed.

• You carry heavy loads or ride a mid-to-heavy e-bike and need a more robust casing.

• You don’t mind the tradeoff in noise, vibration and slightly lower top speed. 

Price, value and real-world ROI

Both tires are listed at similar price points on Hycline’s site (~$59.99 with occasional discounts). For winter riders, the value of a tire is measured not only in miles but in confidence and puncture avoidance. A single avoided roadside fix or avoided rim dent in winter conditions often justifies the price. Rock Conqueror’s heavier construction suggests longer tread life in abrasive off-road winter use; Code: Bones may wear faster if used as a dedicated rock/mud tire, but it will save you time and energy on commutes.

Practical installation & setup tips for winter

1. Go tubeless if your rims support it; lower pressures and sealant are a winter must. If running tubes, keep a fresh, thicker tube and consider slime products for extra puncture resistance.

2. Lower PSI for deep snow, raise for pavement: Start at 6–8 PSI for powder, 8–12 for mixed/firmer packed snow, 18–35 for pavement use on Code: Bones. Rock Conqueror tolerates low pressures but will feel heavy regardless. 

3. Check bead seating in cold: Cold rubber stiffens; warm tires slightly in sun before seating and inspect bead seating carefully.

4. Refresh sealant often in winter because cold thickens sealant and reduces sealing speed.

5. Watch for salt & chemical corrosion—wash and rinse rims and spokes after salty rides.

Limitations of this review (methodological transparency)

• The numeric surface ratings above are inferred from the product specs, manufacturer claims, and owner review themes on Hycline’s pages; they are not the product of a lab or controlled on-bike testing I personally executed in the field as part of this answer. For verified, instrumented wattage vs. speed curves and tabulated puncture/tread wear logs, a field test with identical rims, pressure variants, and power meter would be required. The product pages were explicit about tread design, weight, PSI, TPI and intended application and those data anchor the analysis. 

Final recommendation — a winter buyer’s decision tree

• If your winter is mostly pavement + occasional groomed trail: get Code: Bones. You’ll keep speed and handling without sacrificing too much winter traction. 

• If your winter includes deep snow, mud, rocks, or you carry heavy loads (e-bike): get Rock Conqueror. Accept the slower rotation for the extra confidence and puncture resistance. 

• If you regularly encounter ice sheets, consider adding studded tires or studs to either tire — neither tire ships studded.

Appendix — Key quoted spec lines (source citations)

• Code: Bones specs: Tread Type: Knobby Convex; Sizes 20×4.0 / 26×4.0; ETRTO 102-406 / 98-559; TPI 30; Max inflate 40 PSI; Maximum load 266.6 lbs; Unit weights 2.05 / 2.74 kg. 

• Rock Conqueror specs: Tread Type: Convex Knobs; Sizes 20×4.0 / 26×4.0; ETRTO 102-406 / 102-559; TPI 30; Max inflate 40 PSI; Max load 266.6 lbs; Unit weights 2.5 / 2.8 kg. Hycline: “Oversized Convex Knobs studded tread provides excellent stability and great bite.”