FOX 972-63-129 Float Ctd Boostvalve Stumpjumper 7.75 1.875

( Brand: Fox ), ( Manufacturer Part Number: 972-63-129 ), ( Part Type: Float ), ( Shock Type: Air Shock ), ( Eye To Eye Measurement: 7.75 In ), ( Compatible Bike Type: Mountain Bike ), ( Set Includes: Rear Shock ), ( Stroke Length: 1.875 In )

Review FOX Float Ctd Boostvalve Factory 7.75 Inch 1.875 Stumpjumper

The **Fox 972-63-129 2016 Float CTD Boost Valve** is a precision-engineered suspension component designed specifically for the **2016 Stumpjumper** (and compatible with other Polaris models featuring a 7.75-inch rear axle and 1.875-inch rear shock diameter). This high-performance valve is a critical part of the **CTD (Constant Traction Drive) rear shock system**, engineered to deliver superior traction, stability, and ride quality across a wide range of terrains from rough off-road trails to demanding jump landings. Built with Fox s signature **dual-rate, rebound-adjustable** technology, this valve ensures optimal damping performance by dynamically adjusting to varying loads and terrain conditions, reducing bottoming out and improving overall control. The **floating piston design** within the valve allows for precise tuning of compression and rebound rates, enhancing the shock s responsiveness while minimizing heat buildup during intense use. Whether tackling deep ruts, navigating rocky descents, or executing high-speed jumps, this valve maintains consistent performance by balancing firmness and flexibility, ensuring the rear suspension remains engaged without sacrificing comfort or handling precision. Ideal for riders seeking a **customizable, high-performance suspension upgrade**, the Fox 972-63-129 is a direct replacement for the stock valve, offering a noticeable improvement in traction and ride feel. Its compatibility with the **2016 Stumpjumper s 7.75-inch rear axle and 1.875-inch shock diameter** makes it a seamless fit for those looking to enhance their ATV s off-road capabilities without extensive modifications. With Fox s reputation for durability and innovation, this valve is built to withstand the rigors of frequent use, making it a reliable choice for serious riders who demand the best in suspension technology.

### **Pros and Cons of buying a Fox 972-63-129 (2016 Float CTD Boost Valve, 7.75" x 1.875" for Stumpjumper)**

1. **High-Quality Construction** The Fox 972 series is known for its durable, high-performance materials, including reinforced sidewalls and a robust valve system designed for heavy-duty use.

2. **CTD (Continuous Tubeless Design)** This valve allows for tubeless tire setups, which can improve traction, reduce rolling resistance, and eliminate the risk of pinch flats. It s a modern upgrade over traditional tubes.

3. **Boost Valve Compatibility** The inclusion of a boost valve (7.75" x 1.875") suggests it s designed for higher-pressure applications, which can improve stability and handling on rough terrain, especially for a Stumpjumper, which is often used in off-road or utility settings.

4. **Wide Compatibility** The 7.75" x 1.875" size is common for mid-size SUVs and trucks, making it a versatile choice if you need replacements for other vehicles.

5. **Fox Brand Reputation** Fox is a trusted name in suspension and tire components, offering reliable performance and longevity, especially in demanding conditions.

6. **Float Technology** The "Float" designation indicates a design optimized for comfort and stability over uneven surfaces, reducing harsh impacts compared to standard tires.

7. **Easy Installation** As a direct replacement, it should fit standard rims without modifications, making it a straightforward upgrade or replacement.

---

1. **Cost** High-quality Fox products are premium-priced. Depending on market conditions, this tire could be significantly more expensive than generic or budget alternatives.

2. **Specialized Valve** The CTD boost valve is not standard on all vehicles. If you re not already running tubeless setups, you ll need to ensure compatibility with your rims and wheel wells, which may require additional modifications.

3. **Weight** Performance tires, even those designed for comfort, tend to be heavier than standard all-season tires. This could slightly impact fuel efficiency and handling dynamics.

4. **Wear and Tread Life** Off-road or heavy-duty tires often wear faster than standard tires, especially if used primarily on rough terrain. The 7.75" size may also limit its use to specific applications (e.g., not ideal for highway driving at high speeds).

5. **Limited Availability of Spare Parts** If something goes wrong (e.g., valve failure), finding replacement parts for a Fox CTD boost valve may be harder than for more common valve types.

6. **Potential Overkill for Mild Use** If your Stumpjumper is mostly driven on paved roads or light off-road conditions, this tire may offer unnecessary ruggedness, leading to faster wear without proportional benefits.

7. **Learning Curve for Tubeless Setup** If you re new to tubeless tires, there s a slight learning curve in sealing punctures and maintaining proper pressure, which could be a drawback for some users.

---

The **Fox 972-63-129 (2016 Float CTD Boost Valve, 7.75" x 1.875")** is an excellent choice if you prioritize **durability, off-road performance, and tubeless convenience** for your Stumpjumper. Its reinforced construction, boost valve compatibility, and Fox brand reliability make it a strong investment for heavy-duty or mixed-terrain use. However, the **higher cost, specialized valve requirements, and potential overkill for mild driving** may not justify the purchase for everyone.

- **Buy it if:** You frequently drive off-road, need tubeless reliability, or want a premium tire that enhances stability and comfort on rough terrain. It s also ideal if you re already running a tubeless setup or plan to switch.

- **Avoid it if:** You primarily drive on pavement, are on a tight budget, or lack experience with tubeless systems. In such cases, a more affordable all-terrain tire with a standard valve might suffice.

- **Consider alternatives:** If the price is prohibitive, look for other high-quality tubeless options (e.g., BFGoodrich KO2, Toyo Open Country) or stick with a reliable tubed tire if tubeless isn t a priority.

Ultimately, this Fox tire is a **solid long-term investment** for capable drivers who demand performance and durability, but it s not essential for casual or highway-focused use.

Details:

2015- 2016 Fox Factory Float CTD Boostvalve Rear Shock. Fully functional, climb mode is getting soft, should have standard service soon. Taken off 2016 Specialized Stumpjumper Expert. 7.75 inches x 1.875 stroke.

Piston side is for direct mount to yoke, unique Stumpjumper. Custom Tune ID C2TT. From Fox Service Site. Serial number.

part #: 97263129 prices

• $35.20-$150.00

specifications ribicycl:

• brand: Fox
• mpn: 972-63-129
• part type: Float
• shock type: Air Shock
• eye to eye measurement: 7.75 In
• compatible bike type: Mountain Bike
• set includes: Rear Shock
• stroke length: 1.875 In

shipping ribicycl:

• service: USPS Ground Advantage
• cost: $8.65
• type: Calculated
• transit: 6-13 Days
• carrier: USPS
• class: Standard

general ribicycl:

• condition: Used
• Cycling > Bicycle Components Parts > Rear Shocks

offer ribicycl:

• best offers: True
• options: Ship-to-home
• availability: In Stock
• quantity: 1
• sold: 0
• started: February 7, 2026

seller ribicycl:

• # reviews: 27
• rating: 100.0%
• city: San Diego, California

returns ribicycl:

• policy: No Returns

payments ribicycl:

• credit card: Visa
• wallet: Paypal
• other

Fox 972-63-129 Is Similar To:

• 234-04-550 Fox Shox Float Air Valve For Forks (35.8% similar) Will walk you through creating a label from there. So you'll have to find our phone number with a magical search engine machine of your choice. Lancaster pa, 17603 and out west at 3481 old conj rd. You can trust us...(August 23rd, 2018)
• 234-04-953 Fox New Set Of Float Fork Air Volume Spacers Pn (32.4% similar) The tuning guide information can be found online at. Features: three 34MM 10CC air volume spacers pn can be used to change the ride. We encourage buyers to ask any questions they may have prior placing a bid if are unsure about anything in the offer or purchase. New Fox float 34MM fork air volume ...(January 8th, 2019)
• 3114003sot Fox New Ctd 3 (17.6% similar) For forks the part no. The outer cable and ferrules are not supplied. Is kit this a genuine Fox racing oem and does not come with retail packaging. Is kit and for 2016 FIT4 forks the part no...(November 30th, 2017)
• 3pos-adj Fox Float Dps Evol Rear Shock Off Stumpjumper (43.9% similar) Came on bike but was removed shortly after receiving to run a different shock. Comes as pictured Fox float DPs evil rear shock 3POS-ADJ 210X50 off stumpjumper 29 long travel...(March 22nd, 2019)
• 687928179669 Fox Float Ctd Mtb Fork Evolution Series Tapered (37.7% similar) Buyers are expected to pay all such fees...(October 22nd, 2018)
• 687928181440 Fox New Dhx Boostvalve Rear Shock Mtb Lbs (33.3% similar) A and Taiwan...(August 26th, 2018)
• 803-00-951 Fox Shox Seal Rebuild Kit Float (18.3% similar) ...(March 30th, 2019)
• 803-01-139 Fox Float Volume Spacer Kit Pairs Plastic 702921467923 (23.8% similar) Fox float x2 volume spacer kit 3 pairs: clip-in plastic. Retail price is manufacturers suggested and may not reflect actual selling prices...(March 9th, 2018)
• 803-01-147 Fox Float Seal Kit Part Spring And Damper Rebuild (31.9% similar) Fox part number factory sealed, never opened package. Seal kit to fully service present Fox racing Sioux float x2 rear shocks...(March 4th, 2018)
• 80300142 Fox Suspension Float Rear Shock Rebuild Kit (26.2% similar) New Fox suspension float rear shock rebuild kit, in package part 142FOX air sleeve kit breathe life into your shock maintenance info can be found at...(September 17th, 2018)
• 820-08-379-kit Fox Shox Float Damper Upgrade (26.2% similar) 5 or 29 wheels. Friction reduction during the development of GRIP2, engineering uncovered improvements that greatly reduce. 4-WAY adjust ability the revolutionary design of GRIP2 damper provides independently adjustable high and low-speed compression rebound. Variable valve control Vic fit GRIP2 now...(March 7th, 2019)