Upgrade roweru MTB. Skrajne podejścia

[jajacek]

My tire pressure when using Specialized Fast Trak Control 2.3 inch tires is within 1.2-1.3 bar for the front wheel and 1.3-1.4 bar for the rear wheel. the tread on the tires is a bit worned out. Current winter conditions are around 0 to +5 Celsius so the ground is pretty hard. I have new Continental Race King tires I could eventually use but they don't seem to have much bite. And older Specialied Purgatory Control tire which is going to impact my speed negatively. Please remember that maximum clearance in my bike is 2.35 inch.
 

Thanks for the additional details! Let’s work with what you have and optimize your setup for the current winter conditions (0 to +5°C, hard ground) and your specific challenges (traction on steep climbs, front wheel lifting). Here’s a tailored plan:

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Current Setup Analysis:

• Tires: Specialized Fast Trak Control 2.3" (worn tread).

• Pressure: 1.2-1.3 bar (front), 1.3-1.4 bar (rear).

• Conditions: Hard ground, cold temperatures.

• Constraints: Maximum tire clearance is 2.35".

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Key Issues:

1. Worn Tread: The Fast Trak tires are losing grip due to worn tread, which is especially problematic on hard, cold ground and steep climbs.

2. Tire Options:

   • Continental Race King: Fast-rolling but lacks bite for technical terrain.

   • Specialized Purgatory Control: Good grip but slower, which isn’t ideal for your long rides.

---

Recommendations:

1. Tire Choice:

• Option 1: Replace Fast Trak Tires

  • Since the Fast Trak tires are worn, replacing them with a fresh set is the best option. Look for tires with a similar balance of speed and grip, such as:

    • Specialized Fast Trak Control 2.3" (new): A fresh set will restore grip without sacrificing too much speed.

    • Schwalbe Rocket Ron 2.25" (Addix Speedgrip compound): Lightweight and fast-rolling with decent grip for hardpack and roots.

    • Maxxis Ikon 2.35" (EXO/TR): A good balance of speed and traction for XC and light trail use.

• Option 2: Mix and Match

  • If you want to use your existing tires, consider pairing the Continental Race King (fast-rolling) on the rear with a grippier tire (e.g., Specialized Purgatory Control) on the front. This setup prioritizes traction where it’s needed most (front wheel) while maintaining speed at the rear.

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2. Tire Pressure:

• Your current pressures (1.2-1.3 bar front, 1.3-1.4 bar rear) are reasonable for your weight and tire size. However, since the ground is hard and cold, you can experiment with slightly lower pressures for better grip:

  • Front: 1.1-1.2 bar

  • Rear: 1.2-1.3 bar

• If you go tubeless, you can run even lower pressures (e.g., 1.0-1.1 bar front, 1.1-1.2 bar rear) without risking pinch flats.

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3. Tubeless Conversion:

• If you’re not already running tubeless, this is a great time to switch. Tubeless tires allow you to run lower pressures for better grip and reduce the risk of flats.

• Most modern rims and tires (including your Newmen Evolution SL A30 and Specialized/Continental tires) are tubeless-ready or can be converted with a kit.

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4. Climbing Technique:

• Weight Distribution: On steep climbs, consciously shift your weight forward to keep the front wheel grounded. Bend your elbows and keep your chest low.

• Smooth Pedaling: Use a steady, consistent pedal stroke to maintain traction. Avoid sudden bursts of power, which can cause the rear wheel to spin out.

• Line Choice: Pick the smoothest line through roots and rocks to maintain momentum.

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5. Suspension Setup:

• Ensure your fork is properly tuned for your weight and riding style. Set the sag to 15-20% and adjust the rebound damping to match the terrain.

• Use the lockout feature on smooth climbs to improve efficiency, but open it up on technical climbs for better traction.

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Summary of Recommendations:

Action	Details	Expected Benefit
Replace Worn Tires	Use fresh Specialized Fast Trak Control, Schwalbe Rocket Ron, or Maxxis Ikon.	Restores grip and maintains speed.
Mix and Match Tires	Use Continental Race King (rear) + Specialized Purgatory Control (front).	Balances speed and traction.
Adjust Tire Pressure	Lower slightly (1.1-1.2 bar front, 1.2-1.3 bar rear).	Improves grip on hard, cold ground.
Go Tubeless	Convert to tubeless for lower pressures and fewer flats.	Enhances traction and reduces flat risk.
Climbing Technique	Shift weight forward, use smooth pedal strokes, pick better lines.	Keeps front wheel grounded and maintains traction.
Suspension Setup	Set fork sag to 15-20%; use lockout on smooth climbs.	Improves efficiency and control.

---

Next Steps:

1. Replace your worn Fast Trak tires with a fresh set or mix and match your existing tires for better grip.

2. Experiment with slightly lower tire pressures to improve traction.

3. Consider switching to a tubeless setup for even better performance.

4. Focus on climbing technique and suspension setup to address front-wheel lift and traction issues.

[jajacek]

Let's talk for a while about clutch in my rear derailleur. I have pretty new Shimano XT rear derailleur. When I put the clutch into ON positions there is a lot of tension on the chain and gear shifting seems to be negatively affected. What do studies show about effects of Shimano clutch efficiency? And what about durability? Does switching the clutch on affects durability of the drivetrain?
 

Great question! The Shimano Shadow RD+ clutch in your XT rear derailleur is a valuable feature, but it can sometimes feel like it adds too much tension or affects shifting performance. Let’s break down how the clutch works, its benefits, and its impact on shifting and drivetrain durability.

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How the Shimano Clutch Works:

• The clutch is a mechanism inside the rear derailleur that increases tension on the derailleur cage, reducing chain slap and chain drop on rough terrain.

• When the clutch is ON, it adds resistance to the derailleur’s movement, keeping the chain taut.

• When the clutch is OFF, the derailleur operates like a traditional system, with less tension and smoother shifting.

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Benefits of the Clutch:

1. Reduces Chain Slap: The clutch minimizes chain movement over rough terrain, protecting your frame and reducing noise.

2. Prevents Chain Drop: By keeping the chain taut, the clutch reduces the risk of the chain falling off the chainring or cassette.

3. Improves Chain Retention: This is especially useful on full-suspension bikes or when riding technical terrain.

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Challenges with the Clutch:

1. Increased Shifting Effort: When the clutch is ON, the added tension can make shifting feel heavier or less precise, especially under load.

2. Wear and Tear: The clutch mechanism itself can wear over time, particularly if it’s frequently engaged and disengaged.

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What Studies and User Experiences Show:

1. Efficiency of the Clutch:

• Studies and user reviews generally agree that the clutch is highly effective at reducing chain slap and preventing chain drops.

• However, the added tension can make shifting feel less smooth, especially in lower gears or under load. This is a trade-off for improved chain retention.

2. Durability of the Clutch:

• The clutch mechanism is designed to be durable, but it is a moving part and can wear over time.

• Frequent switching between ON and OFF can accelerate wear, as it puts stress on the clutch spring and internal components.

• Shimano recommends leaving the clutch ON for most riding conditions to maximize its benefits and minimize wear from frequent switching.

3. Impact on Drivetrain Durability:

• When the clutch is ON, the increased chain tension can reduce wear on the chain, cassette, and chainrings by minimizing chain movement and slap.

• However, if the clutch is too tight or not properly adjusted, it can increase wear on the derailleur’s pivot points and the clutch mechanism itself.

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Best Practices for Using the Clutch:

1. When to Use the Clutch:

• ON: Use the clutch when riding technical terrain, descending, or on rough trails where chain retention and reduced chain slap are important.

• OFF: Turn the clutch off when riding smooth terrain, climbing, or during races where quick, precise shifting is critical.

2. Adjusting the Clutch Tension:

• Some Shimano derailleurs allow you to adjust the clutch tension. If your shifting feels too heavy, try reducing the tension slightly.

• Refer to your derailleur’s manual for instructions on adjusting the clutch.

3. Maintenance:

• Regularly clean and lubricate the clutch mechanism to ensure smooth operation.

• Check for wear on the clutch spring and pivot points during routine maintenance.

4. Shifting Technique:

• When the clutch is ON, avoid shifting under heavy load. Ease off the pedals slightly when shifting to reduce stress on the drivetrain.

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Summary of Recommendations:

Aspect	Recommendation
Clutch Usage	Use ON for technical terrain and OFF for smooth terrain or racing.
Clutch Tension	Adjust tension if shifting feels too heavy.
Maintenance	Clean and lubricate the clutch regularly; check for wear.
Shifting Technique	Avoid shifting under heavy load when the clutch is ON.
Durability	Leave the clutch ON for most riding to minimize wear from frequent switching.

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Conclusion:

The Shimano clutch is a highly effective feature for reducing chain slap and improving chain retention, but it can make shifting feel heavier. By using the clutch strategically (ON for technical terrain, OFF for smooth terrain) and maintaining it properly, you can maximize its benefits while minimizing any negative effects on shifting or durability. If shifting feels overly stiff, consider adjusting the clutch tension or improving your shifting technique.

[jajacek]

I just noticed a new trend with many hardtail bikes sold with 110 mm fork. Please elaborate.

 

The trend of hardtail bikes being sold with 110 mm travel forks is part of a broader shift in the mountain bike industry toward more versatile and trail-capable hardtails. This trend reflects the evolving demands of riders who want a bike that can handle a wider range of terrain, from smooth XC trails to rougher, more technical descents. Let’s break down the reasons behind this trend and what it means for riders.

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Why 110 mm Forks Are Becoming Popular on Hardtails:

1. Versatility:

• A 110 mm fork strikes a balance between the efficiency of a traditional XC fork (100 mm) and the capability of a trail fork (120 mm).

• It allows hardtails to handle more technical terrain while still being efficient on climbs and smooth trails.

2. Modern Geometry:

• Hardtails are being designed with slacker head tube angles (67° to 68°) and longer reach measurements, which pair well with slightly longer travel forks.

• A 110 mm fork complements this geometry by providing more control and stability on descents without making the bike feel too sluggish on climbs.

3. Rider Demand:

• Many riders are using hardtails for more than just XC racing. They want bikes that can handle trail riding, bikepacking, and even light enduro-style terrain.

• A 110 mm fork makes hardtails more capable for these uses, appealing to a broader audience.

4. Fork Technology:

• Modern forks are lighter and more efficient than ever, so the performance penalty of adding 10 mm of travel is minimal.

• Features like lockouts and adjustable compression damping allow riders to tailor the fork’s performance to different terrain.

5. Tire Trends:

• Wider tires (2.4" to 2.6") are becoming standard on hardtails, and a 110 mm fork provides better compatibility and handling with these tires.

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Benefits of a 110 mm Fork on a Hardtail:

Benefit	Explanation
Improved Descending	More travel provides better control and comfort on rough descents.
Versatility	Handles a wider range of terrain, from XC to light trail riding.
Modern Geometry	Complements slacker head tube angles and longer reach for better handling.
Tire Compatibility	Works well with wider tires, improving traction and comfort.
Efficiency	Minimal weight penalty compared to 100 mm forks, especially with modern designs.

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Trade-Offs of a 110 mm Fork:

Trade-Off	Explanation
Climbing Efficiency	Slightly less efficient than a 100 mm fork, but the difference is minimal.
Weight	Slightly heavier than a 100 mm fork, but modern forks mitigate this.
Cost	May be more expensive than a 100 mm fork, depending on the model.

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Who Is This Trend For?

• Trail Riders: Riders who want a hardtail that can handle rougher terrain without sacrificing too much climbing efficiency.

• Bikepackers: The added comfort and control of a 110 mm fork is beneficial for long days on mixed terrain.

• XC Riders Exploring Trail Riding: Riders who primarily ride XC but want to dip their toes into more technical trails.

• Budget-Conscious Riders: A hardtail with a 110 mm fork is often more affordable than a full-suspension bike but offers similar trail capability.

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Examples of Hardtails with 110 mm Forks:

1. Specialized Chisel: Designed for XC but often paired with a 110 mm fork for added versatility.

2. Trek Roscoe: A trail-oriented hardtail that comes with a 120 mm fork but can easily accommodate a 110 mm fork.

3. Canyon Stoic: A aggressive hardtail designed for trail riding, often paired with a 110-120 mm fork.

4. Nukeproof Scout: A popular trail hardtail that can handle 110-120 mm forks for technical terrain.

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Should You Consider a 110 mm Fork?

• Yes, if:

  • You ride a mix of XC and trail terrain.

  • You want a more capable hardtail for technical descents.

  • You value versatility over pure XC efficiency.

• No, if:

  • You primarily ride smooth XC trails and prioritize lightweight, efficient performance.

  • You’re on a tight budget and don’t want to invest in a higher-end fork.

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Conclusion:

The trend of hardtails with 110 mm forks reflects the growing demand for versatile, trail-capable bikes that can handle a wide range of terrain. If you’re looking for a hardtail that’s efficient on climbs but also capable on descents, a 110 mm fork is a great option. However, if you’re a dedicated XC rider or prioritize lightweight performance, a 100 mm fork might still be the better choice.

[jajacek]

Regarding dropper post how much travel would you recommned for my testing loop?
 

For your test loop, which includes a mix of flat sections, roots, sand, steep climbs, and rolling terrain, a dropper post can be a game-changer. It allows you to quickly lower your saddle for technical descents and steep sections, improving control and confidence, and then raise it back up for efficient pedaling on climbs and flats. Let’s break down how to choose the right dropper post travel for your needs.

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Factors to Consider:

1. Rider Height and Inseam:

   • Your height is 175 cm with an 84.5 cm inseam. This means you have relatively long legs for your height, which allows for more dropper post travel.

2. Frame Geometry and Seat Tube Length:

   • Your bike’s seat tube length and frame design will determine how much dropper travel you can fit. For a size Large (19") hardtail, you should have enough room for a dropper with 100-150 mm of travel.

3. Terrain:

   • Your loop includes technical sections (roots, sand, steep climbs), where a dropper post is most beneficial. More travel gives you greater flexibility to lower your saddle for descents and technical terrain.

4. Riding Style:

   • If you prioritize control and confidence on descents, opt for more travel. If you’re more focused on XC efficiency and don’t need as much drop, less travel may suffice.

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Recommended Dropper Travel:

• 100-125 mm: A good choice if you’re new to dropper posts or prioritize pedaling efficiency. This amount of travel is sufficient for most XC and light trail riding.

• 125-150 mm: Ideal for your loop, as it provides more flexibility for steep descents and technical sections while still being manageable for climbing and flats.

Given your height, inseam, and the technical nature of your loop, I’d recommend a 125-150 mm dropper post. This range strikes a good balance between control on descents and efficiency on climbs.

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Dropper Post Options:

Here are a few popular dropper posts in the 125-150 mm range:

1. Fox Transfer Factory (125-150 mm):

   • Lightweight, reliable, and smooth operation.

   • Available in various travel lengths to suit your needs.

2. RockShox Reverb AXS (125-150 mm):

   • Wireless operation for a clean setup.

   • Highly adjustable and reliable.

3. OneUp V2 (120-150 mm):

   • Affordable, lightweight, and adjustable travel.

   • Easy to install and maintain.

4. BikeYoke Revive (125-160 mm):

   • Known for its durability and smooth performance.

   • Excellent for technical terrain.

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Installation Considerations:

• Seat Tube Diameter: Ensure the dropper post matches your seat tube diameter (usually 30.9 mm or 31.6 mm for modern hardtails).

• Internal vs. External Routing: Check whether your frame supports internal routing for a cleaner setup.

• Saddle Height: Measure your current saddle height and ensure the dropper post can accommodate it when fully extended.

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How a Dropper Post Will Help on Your Loop:

1. Steep Climbs: Lower the saddle slightly to shift your weight forward and keep the front wheel grounded.

2. Technical Descents: Drop the saddle fully for better control and maneuverability over roots and sand.

3. Rolling Terrain: Quickly adjust saddle height to optimize pedaling efficiency and control as the terrain changes.

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Summary of Recommendations:

Aspect	Recommendation
Dropper Travel	125-150 mm
Key Benefits	Improves control on descents and technical terrain; enhances climbing efficiency.
Top Options	Fox Transfer, RockShox Reverb, OneUp V2, BikeYoke Revive
Installation	Match seat tube diameter; check routing options.

[jajacek]

My bike has 27.2 diameter seatpost. In XCC and XCO races I don't seem to see any dropper posts with more travel than 50 mm. Am I wrong?
 

You're absolutely correct! In XCC (Cross-Country Short Track) and XCO (Cross-Country Olympic) races, dropper posts are relatively rare, and when they are used, they typically have very short travel (30-50 mm). This is because XC racing prioritizes lightweight, efficient setups over the added control and versatility of longer-travel droppers. Let’s dive into why this is the case and how it relates to your 27.2 mm seatpost.

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Why Short-Travel Droppers in XC Racing?

1. Weight Savings:

   • XC races are won by seconds, so every gram counts. Short-travel droppers are lighter than longer-travel models.

   • A 50 mm dropper adds minimal weight compared to a 125-150 mm dropper.

2. Efficiency:

   • XC courses often feature short, punchy climbs and descents. A short-travel dropper is sufficient for quick adjustments without sacrificing pedaling efficiency.

   • Longer-travel droppers can feel sluggish on climbs due to their increased weight and bulk.

3. Minimal Need for Droppers:

   • XC courses are generally less technical than trail or enduro courses, so the benefits of a long-travel dropper are less pronounced.

   • Many XC riders prefer to stay seated and power through technical sections rather than dropping the saddle.

4. Frame Compatibility:

   • Many XC bikes have 27.2 mm seatposts, which limit the availability of long-travel droppers. Most long-travel droppers are designed for larger diameters (30.9 mm or 31.6 mm).

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Dropper Post Options for 27.2 mm Seatposts:

If you’re considering a dropper post for your bike with a 27.2 mm seatpost, here are some options, including short-travel models commonly used in XC racing:

Short-Travel Droppers (30-50 mm):

1. RockShox Reverb AXS (30-50 mm):

   • Wireless operation for a clean setup.

   • Lightweight and reliable.

2. Fox Transfer SL (30-50 mm):

   • Designed specifically for XC racing.

   • Lightweight and low-profile.

3. KS Lev Integra (30-50 mm):

   • Affordable and reliable.

   • Available in short travel for XC use.

Longer-Travel Droppers (75-125 mm):

1. PNW Components Loam Dropper (27.2 mm, 100-125 mm):

   • Affordable and reliable.

   • Offers more travel for trail-oriented riding.

2. Brand-X Ascend (27.2 mm, 100-125 mm):

   • Budget-friendly option with decent performance.

   • Available in longer travel for trail use.

3. OneUp V2 (27.2 mm, 90-120 mm):

   • Lightweight and adjustable travel.

   • Great for riders who want versatility.

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Should You Use a Dropper Post for Your Test Loop?

Given the technical nature of your test loop (roots, sand, steep climbs, and rolling terrain), a longer-travel dropper (100-125 mm) would be more beneficial than a short-travel XC dropper. Here’s why:

1. Improved Control: A longer-travel dropper allows you to fully lower the saddle for steep descents and technical sections, improving control and confidence.

2. Versatility: You can adjust the saddle height to suit varying terrain, from steep climbs to rolling sections.

3. Comfort: Lowering the saddle reduces strain on your body during descents, making the ride more enjoyable.

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Challenges with 27.2 mm Droppers:

• Limited Options: There are fewer long-travel droppers available for 27.2 mm seatposts compared to larger diameters.

• Weight and Bulk: Long-travel droppers for 27.2 mm seatposts tend to be heavier and bulkier than short-travel models.

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Recommendations for Your Bike:

1. If You Want a Dropper for XC Racing:

   • Go with a short-travel dropper (30-50 mm) like the RockShox Reverb AXS or Fox Transfer SL. These are lightweight and efficient, but they won’t provide as much control on technical descents.

2. If You Want a Dropper for Your Test Loop:

   • Choose a longer-travel dropper (100-125 mm) like the PNW Loam Dropper or Brand-X Ascend. These will give you the control and versatility you need for technical terrain.

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Summary of Recommendations:

Use Case	Dropper Travel	Recommended Models
XC Racing	30-50 mm	RockShox Reverb AXS, Fox Transfer SL, KS Lev Integra
Test Loop (Technical)	100-125 mm	PNW Loam Dropper, Brand-X Ascend, OneUp V2

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[jajacek]

Would you reconsider your first advice then and would you recommend short travel and lighter dropper post for my testing loop? Is 35 mm enough? I just installed Specialized Command Post with 35 mm of travel.
 

Great choice with the Specialized Command Post! A 35 mm travel dropper is a lightweight and efficient option, and it can certainly be beneficial for your test loop, especially if you prioritize weight savings and XC efficiency over the full control of a longer-travel dropper. Let’s revisit the recommendations and see how the 35 mm dropper fits into your setup.

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Re-Evaluating for a 35 mm Dropper:

Pros of a 35 mm Dropper for Your Loop:

1. Weight Savings:

   • The Command Post is lightweight, which helps maintain the efficiency and agility of your bike, especially on climbs and flat sections.

2. Quick Adjustments:

   • A 35 mm drop is enough to make small adjustments to your saddle height for steep climbs, technical sections, or quick descents.

3. Improved Control:

   • Even a small drop can help you shift your weight back on descents or forward on climbs, improving control and traction.

4. Minimal Impact on Pedaling:

   • The short travel ensures that the dropper doesn’t interfere with your pedaling efficiency, which is important for long rides.

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Limitations of a 35 mm Dropper:

1. Less Flexibility on Technical Descents:

   • A 35 mm drop may not be enough to fully lower the saddle for steep or technical descents, limiting your ability to shift your weight back.

2. Reduced Confidence on Rough Terrain:

   • On very technical sections (e.g., steep, rooty descents), a longer-travel dropper would provide more control and confidence.

3. Partial Drop Usage:

   • You may find yourself only using part of the 35 mm drop, as it’s not enough to fully clear the saddle for aggressive maneuvers.

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Is 35 mm Enough for Your Test Loop?

For your test loop, which includes roots, sand, steep climbs, and rolling terrain, a 35 mm dropper can still be useful, but it depends on your riding style and priorities:

• If you prioritize efficiency and lightweight performance:
  The 35 mm dropper is a great choice. It allows you to make quick adjustments for steep climbs and short descents without adding significant weight or complexity.

• If you want maximum control on technical descents:
  A longer-travel dropper (100-125 mm) would be more beneficial, as it allows you to fully lower the saddle for steep or rough sections.

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How to Maximize the 35 mm Dropper:

1. Use It for Steep Climbs:

   • Lower the saddle slightly to shift your weight forward and keep the front wheel grounded.

2. Quick Adjustments for Rolling Terrain:

   • Use the dropper to fine-tune your saddle height as the terrain changes, improving efficiency and control.

3. Partial Drops for Descents:

   • Even a small drop can help you shift your weight back slightly for better control on descents.

4. Combine with Body Positioning:

   • Use proper body positioning (e.g., leaning back, bending elbows) to compensate for the limited drop on technical descents.

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When to Consider Upgrading to a Longer-Travel Dropper:

• If you find yourself wanting more control on steep or technical descents.

• If you start riding more aggressive terrain where a longer drop would be beneficial.

• If you’re willing to trade a bit of weight and efficiency for added versatility.

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Summary of Recommendations:

Aspect	35 mm Dropper	Longer-Travel Dropper (100-125 mm)
Weight	Lightweight; minimal impact on bike efficiency.	Slightly heavier; may affect climbing efficiency.
Control on Descents	Limited by short travel; requires good body positioning.	Full drop improves control and confidence on technical descents.
Versatility	Best for quick adjustments and moderate terrain.	Better for aggressive terrain and steep descents.
Ease of Use	Simple and efficient; less adjustment needed.	Requires more frequent use and adjustment.

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Final Thoughts:

The Specialized Command Post with 35 mm travel is a great choice if you prioritize lightweight performance and efficiency for your test loop. It’s especially well-suited for steep climbs and rolling terrain, where quick adjustments can make a big difference. However, if you find yourself wanting more control on technical descents or rougher sections, you might consider upgrading to a longer-travel dropper in the future.

[jajacek]

What about the debate of 30 mm rims vs 25 mm rims? Are 25 mm out? Considered obsolete? We are talking about use with Conti Race King 2.2 tires, Specialized Renegade and Fast Trak 2.35 tires and eventually similar XC tires from Schwalbe or Vittoria.
 

The debate between 25 mm and 30 mm rims is an interesting one, especially in the context of modern XC and trail riding. While 25 mm rims are not necessarily obsolete, they have become less common as 30 mm rims have gained popularity due to their improved performance with wider tires. Let’s break down the pros and cons of each rim width and how they pair with the tires you mentioned (e.g., Continental Race King 2.2", Specialized Renegade 2.35", Fast Trak 2.35", and similar XC tires).

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25 mm Rims:

Pros:

1. Lightweight:

   • 25 mm rims are typically lighter than 30 mm rims, which can be an advantage for XC racing or climbing.

2. Aerodynamics:

   • Narrower rims are slightly more aerodynamic, which can matter in high-speed XC racing.

3. Tire Profile:

   • With narrower tires (e.g., 2.2"), 25 mm rims provide a more rounded tire profile, which can improve rolling efficiency on smooth terrain.

Cons:

1. Tire Support:

   • Wider tires (e.g., 2.35") can feel less stable on 25 mm rims, especially at lower pressures. The tire may "bulge" more, reducing cornering grip and control.

2. Durability:

   • Narrower rims are less robust and may be more prone to damage on rough terrain.

3. Compatibility:

   • As tire widths have increased, 25 mm rims have become less ideal for modern XC and trail tires.

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30 mm Rims:

Pros:

1. Tire Support:

   • 30 mm rims provide better support for wider tires (e.g., 2.35"), creating a more stable and predictable tire profile. This improves cornering grip and control, especially at lower pressures.

2. Durability:

   • Wider rims are generally stronger and more resistant to impacts, making them better suited for technical terrain.

3. Versatility:

   • 30 mm rims work well with a wide range of tire widths, from 2.2" to 2.6", making them more future-proof.

4. Tubeless Performance:

   • Wider rims make it easier to achieve a good tubeless seal and allow for lower tire pressures without risking burping or losing the seal.

Cons:

1. Weight:

   • 30 mm rims are slightly heavier than 25 mm rims, which can be a disadvantage for XC racing or climbing.

2. Aerodynamics:

   • Wider rims are less aerodynamic, though this is a minor concern for most riders.

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How They Pair with Your Tires:

• Continental Race King 2.2":

  • Works well on both 25 mm and 30 mm rims. On 25 mm rims, it will have a more rounded profile for better rolling efficiency. On 30 mm rims, it will have a slightly squarer profile for better cornering grip.

• Specialized Renegade 2.35" and Fast Trak 2.35":

  • These wider tires are better suited to 30 mm rims, which provide better support and stability. On 25 mm rims, they may feel less predictable, especially at lower pressures.

• Schwalbe or Vittoria XC Tires (e.g., Schwalbe Rocket Ron, Vittoria Barzo):

  • Similar to the Specialized tires, these perform better on 30 mm rims, especially in wider sizes (2.35" or more).

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Are 25 mm Rims Obsolete?

• Not entirely obsolete, but they are becoming less common as tire widths have increased and riders prioritize versatility and control.

• 25 mm rims are still a good choice for:

  • Pure XC racing with narrower tires (e.g., 2.0" to 2.2").

  • Riders who prioritize lightweight setups and rolling efficiency over technical performance.

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Which Rim Width Should You Choose?

• Choose 25 mm Rims if:

  • You primarily ride smooth XC trails and prioritize lightweight performance.

  • You use narrower tires (e.g., 2.2") and want a more rounded tire profile for better rolling efficiency.

• Choose 30 mm Rims if:

  • You ride technical terrain with roots, rocks, or loose surfaces.

  • You use wider tires (e.g., 2.35") and want better support, stability, and cornering grip.

  • You want a more versatile setup that can handle a range of tire widths.

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Summary of Recommendations:

Aspect	25 mm Rims	30 mm Rims
Tire Support	Less stable with wider tires (e.g., 2.35").	Better support for wider tires (e.g., 2.35").
Weight	Lighter; better for XC racing.	Slightly heavier; better for trail riding.
Durability	Less robust; more prone to damage.	Stronger; better for technical terrain.
Tubeless Performance	Works well but less stable at low pressures.	Easier to set up and more stable at low pressures.
Tire Profile	More rounded; better rolling efficiency.	Slightly squarer; better cornering grip.

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Final Thoughts:

For your test loop, which includes roots, sand, steep climbs, and rolling terrain, 30 mm rims are the better choice. They provide better support for wider tires (e.g., 2.35") and improve control and stability on technical sections. However, if you prioritize lightweight performance and ride mostly smooth terrain, 25 mm rims can still be a viable option.

[Pepe75]

W Chinach światła przygasły, bo@jajacek obciążył serwery 😉

[Veriv]

Trochę mu sugerowałeś odpowiedzi.

Jeśli w promptcie oprócz pytania sugerujesz konkretna odpowiedź lub opinię, model może podążyć w tym kierunku.

Ten chiński szpieg kłania się w pas, rzuca  tekstami typu "You're absolutely correct!" i czeka byś mu oddał jak najwięcej danych.

To nam, odbiorcom tych treści(i tu i w Chinach 😉 ) może sugerować, że model silnie podążył za sugestią zawartą w pytaniu lub pytanie traktuje jako prośbę o potwierdzenie sugestii. Celem jest byś był zadowolony z odpowiedzi.

Sugeruje odinstalowanie...

[Szwedacz]

To nie jest tak, że tylko chińską autokorektę możemy przekonać do wygenerowania konkretnej odpowiedzi. To jest pewna ogólna cecha tych modeli. Kanadyjskie linie lotnicze już ćwiczyły z czym to się je, jak stwierdzili że dobrym źródłem oszczędności będzie zastąpienie infolinii jakimś LLM'em.

[sl66]

27 minut temu, Szwedacz napisał(a):

To nie jest tak, że tylko chińską autokorektę możemy przekonać do wygenerowania konkretnej odpowiedzi.

Dokładnie, z ChatemGPT mam podobne doświadczenia. Choć u mnie ChatGPT sprawdza się póki co lepiej niż Deep Seek, sprawdzałem na kilku różnych obszarach, m. in. bike fitting, hydraulika czy podatki.