About The Product
- Factory replacement high-performance disc brake pads
- Performance braking in extreme conditions
Upgrade Your Brake Performance with Koolstop D640S Clarks M4 / Shimano Saint M810, M820, M640, M8020, TRP G-Spec E-MTB, Quadiem, Slate Evo Disc Brake Pads
Experience superior stopping power and reliable performance in all riding conditions with the Koolstop D640S disc brake pads, expertly engineered for high-performance mountain biking and e-MTB applications. These factory replacement pads are designed to seamlessly fit Clarks M4, Shimano Saint (M810, M820, M640, M8020), TRP G-Spec, Quadiem, and Slate Evo brake systems, making them an essential upgrade for serious cyclists seeking optimal braking performance.
Materials & Engineering
Crafted from premium sintered metallic compounds, Koolstop D640S pads deliver exceptional durability and consistent braking force-even in extreme weather and challenging terrains. The sintered material provides high resistance to heat and wear, ensuring maximum pad life and reliable performance during aggressive descents and long rides. The steel backplates are precisely engineered for compatibility and stability, with copper plating on sintered pads for enhanced heat dissipation and corrosion resistance. For e-bike riders, these pads feature a ceramic-backed design with an organic front material, balancing power with noise reduction and longevity.
Components & Technology
Utilizing advanced sintered technology, these brake pads offer excellent modulation and powerful stopping capability in all environments. The blend of organic materials in the front compound provides smooth, quiet braking and consistent grip from the first pedal stroke to the last. Designed as high-performance factory replacements, they are engineered to optimize your existing disc brake system's efficiency and responsiveness.
Style & Use Case
Designed for serious mountain biking, enduro, and e-bike adventures, the Koolstop D640S pads excel in downhill descents, technical climbs, and everyday trail riding. Their robust construction and compatibility with various high-end brake systems make them the perfect choice for riders demanding confidence and control on rugged trails or steep climbs. Whether tackling mud, water, or dry conditions, these pads deliver reliable, powerful braking when you need it most.
Innovative Features & Differentiators
- Compatible with top-tier brake systems including Shimano Saint, Clarks M4, TRP G-Spec, Quadiem, and Slate Evo
- Sintered metallic compound for maximum durability and stopping power in extreme conditions
- Organic front material with ceramic-backed design for quiet operation and reduced wear
- Steel backplates with copper plating for improved heat management
- Designed specifically for electric bikes (E-MTB), addressing the unique demands of e-biking
Optimize your braking system today with Koolstop D640S disc brake pads-trusted by cyclists worldwide for their performance, durability, and peace of mind on every ride. Perfect for aggressive trail riding, downhill racing, and e-MTB adventures, these pads ensure you stay in control no matter the terrain.
- Optimized for high-performance braking, these Koolstop D640S Clarks M4 and Shimano Saint M810/M820/M640/M8020 disc brake pads deliver exceptional stopping power and modulation for demanding mountain biking and e-MTB applications.
- Constructed with durable sintered metallic compounds, these pads provide reliable performance in harsh conditions, including mud, rain, and steep descents, ensuring maximum brake fade resistance and extended pad life.
- Designed with high-quality steel backplates featuring copper plating for enhanced heat dissipation and corrosion resistance, these replacement brake pads are compatible with a variety of popular brake systems including Clarks, Shimano Saint, TRP G-Spec, Quadiem, and Slate Evo models.
- Engineered for versatility, these organic and sintered pad options offer a balance of modulation, power, and durability, making them suitable for both trail riding and aggressive downhill mountain biking.
- Innovative features include ceramic-backed e-bike pads for improved heat management on electric mountain bikes, ensuring consistent braking performance and safety during high-speed e-MTB riding sessions.
| Specification | Value |
|---|---|
| Manufacturer | KOOLSTOP |
| Manufacturer Part No. | KS-D640S |
| Universal Product Code | 760251076352 |
| Invoice Description | BRAKE SHOES K/S DISC SHI ZEE/SAINT SINT/STL w/SPRING |
| Shipping Weight | 0.07 lbs. |
| Package Dimensions | 5.15 x 3.2 x 0.5 |
| Country of Origin | UNITED STATES |
| Pad Style ID | 31 |
| Compatibility | Clarks M4 / Shimano Saint M810, M820, M640, M8020 / TRP G-Spec E-MTB, Quadiem, Quadiem G-Spec, Slate Evo, Slate T4 |
| Pad Material | Sintered |
| Compound | Standard |
| Brand | Kool-Stop |
| Backplate | Steel |
- Supplier:
- JBI
Bike Junkies offers no‑hassle returns and exchanges within 60 days of delivery. We want every customer to feel confident when shopping with us, and our return process is designed to be simple, fair, and fast.
Return Eligibility
To qualify for a return or exchange, the following conditions must be met:
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The item must be in new, unused, and uninstalled condition.
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All original packaging, tags, hardware, and accessories must be included and intact.
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Items showing wear, installation marks, damage, or improper use cannot be accepted.
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An order number is required.
Once your return is received at our warehouse, a refund will be issued within 5 days after inspection.
Refunds
Refunds are issued to the original form of payment once the returned item has been received and approved. If we are unable to refund to the original payment method, the refund will be issued as store credit.
Depending on your bank or credit card provider, it may take an additional 2–3 business days for the refund to appear in your account.
Exchanges
To make an exchange, simply complete the return process and then place a new order for the item you want instead. This ensures the replacement item is reserved and ships quickly.
How to Start a Return
To request a Return Authorization (RA#), contact us at support@bikejunkies.com. Please include your order number and the item you wish to return.
Once approved:
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You will receive a Return Authorization email with instructions.
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Print the prepaid label provided by us. ($9.99 will be deducted from your refund)
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Ship the item back within 7 days of the RA being issued as RA #'s are only valid for 7 days.
Please do not tape anything to the original product packaging. Place the item inside a proper shipping box. Using the manufacturer’s box as the shipping container will result in damage and the return may be rejected.
Be sure to keep your return tracking number. Powersport Junkies is not responsible for lost return shipments. You will receive a confirmation email once your return has been processed and refunded.
Defective, Incorrect, or Damaged Items
If you receive a defective, damaged, or incorrectly shipped item, contact us immediately. We will cover the return shipping cost and ensure the issue is resolved quickly.
Non‑Returnable Items
Certain items cannot be returned, including:
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Electronics with opened packaging or broken manufacturer seals
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Any part that has been installed or shows installation attempts
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Tools or chemicals that have been opened or unsealed
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Open‑box items with destroyed or missing packaging
Our Info
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Storefront name: Bike Junkies
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Address: 940 Calle Amanecer, Suite N
San Clemente, CA 92673 -
Phone: 800-605-2152
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Support email: support@bikejunkies.com
- Support hours + timezone:
Monday-Friday: 9:00 AM-5:00 PM PST
Saturday: 9:00 AM-3:00 PM PST
Sunday: Closed
This Shipping Policy explains how orders are processed, handled, and delivered by Bike Junkies, including delivery timelines, shipping coverage, and special conditions for military addresses. It is designed to give customers a clear understanding of what to expect when placing an order.
Bike Junkies is proud to be an authorized dealer of the brands we currently offer. When you purchase from us, you are guaranteed to receive genuine, brand-new products backed by the full manufacturer warranty. We work directly with the manufacturers to ensure you receive the highest quality service and support.
Order Processing and Handling
Orders are processed quickly to ensure fast delivery. Our standard handling time is 0–1 business days. Order cutoff time is 12 PM PST Monday-Friday and orders placed after that will be shipped shipped next business day.
Transit Times
Once shipped, orders typically arrive within 2–3 business days. Transit times may vary slightly depending on the destination, weather conditions, or carrier-related delays. Delivery estimates apply only after the order has left our facility.
Delivery Schedule
Standard delivery occurs Monday through Friday. Saturday delivery may be available.
Shipping Coverage
Bike Junkies offers free shipping to the lower 48 states of the United States. We do not ship to the following locations:
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Alaska
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Hawaii
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Puerto Rico
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Any international destination outside the United States
Orders placed with shipping addresses in restricted locations will be canceled and refunded.
Military Shipping (APO/FPO)
Bike Junkies ships to APO/FPO military addresses using USPS only.
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We cannot ship hazardous materials or oversized items to military addresses due to carrier and military mail restrictions.
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Transit times to APO/FPO locations may vary significantly depending on military mail processing.
Address Accuracy and Delivery Issues
Customers are responsible for ensuring that all shipping information provided at checkout is accurate and complete. Bike Junkies is not responsible for delays, lost packages, or delivery failures caused by incorrect or incomplete addresses. If a package is returned due to an address error, additional shipping charges may apply to resend the order.
Lost, Delayed, or Damaged Shipments
If a shipment is delayed, lost, or arrives damaged, customers should contact us promptly so we can assist with initiating a claim or resolving the issue with the carrier. While we support the process, final decisions regarding claims are made by the carrier.
Tracking Information
A tracking number is provided via email once the shipping label has been created. Tracking updates may take up to 24 hours to appear after the label is generated.
Shipping Restrictions
Certain items may be subject to shipping restrictions due to size, weight, or hazardous material regulations. If an order cannot be shipped due to such restrictions, we will notify the customer to arrange an alternative solution.
Our Info
-
Storefront name: Bike Junkies
-
Address: 940 Calle Amanecer, Suite N
San Clemente, CA 92673 -
Phone: 800-605-2152
-
Support email: support@bikejunkies.com
- Support hours + timezone:
Monday-Friday: 9:00 AM-5:00 PM PST
Saturday: 9:00 AM-3:00 PM PST
Sunday: Closed
For warranty issues please contact us at support@bikejunkies.com. Each Brand is different and we can provide instruction to complete warranty issues.
Bike Junkies is proud to be an authorized dealer of the brands we currently offer. When you purchase from us, you are guaranteed to receive genuine, brand-new products backed by the full manufacturer warranty. We work directly with the manufacturers to ensure you receive the highest quality service and support.
Our Info
-
Storefront name: Bike Junkies
-
Address: 940 Calle Amanecer, Suite N
San Clemente, CA 92673 -
Phone: 800-605-2152
-
Support email: support@bikejunkies.com
- Support hours + timezone:
Monday-Friday: 9:00 AM-5:00 PM PST
Saturday: 9:00 AM-3:00 PM PST
Sunday: Closed
