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The Shimano XT CS-M8100 12-Speed Cassette is engineered for mountain biking enthusiasts seeking optimal performance across diverse terrains. Available in two gear configurations—10-45T and 10-51T—it offers a wide range of gearing options to suit various riding styles. The cassette features Shimano's HYPERGLIDE+ technology, ensuring fast and smooth shifting, while the BEAM SPIDER construction reduces weight and inertia for improved acceleration and chain security. Designed with a Micro Spline freehub body, it accommodates a 10T cog, providing enhanced durability and compatibility with modern drivetrains.
Key Features:
HYPERGLIDE+ technology for fast and smooth shifting
BEAM SPIDER construction reduces weight and inertia
Micro Spline freehub body accommodates 10T cog
Available in 10-45T and 10-51T gear configurations
Compatible with Shimano HG 12-speed chains
Optimized for mountain biking applications
Weight: 461g (10-45T), 470g (10-51T)
Receive free shipping on orders over $50!
Learn more about Shipping options
Return or exchange your product within 60 days!
View our Returns Policy
Our team of pros are here to help!
Contact us today 844-786-6486
*Some exclusions may apply.
If your order total is $50 or more, you qualify for free UPS Ground shipping. Free shipping offers are applied to your order total after any promotions or credits are applied. Large or heavy items such as bicycles, paddle boards, kayaks, cargo boxes, and more may not qualify for our free shipping offer or may only be available for in-store pickup. For products with these restrictions, available shipping options will surface on the product page or at checkout.
Please note: Free shipping offers apply only to orders shipping within the contiguous United States (lower 48 states). Orders shipping to Alaska, Hawaii, or Puerto Rico are excluded from our free shipping offer and will be subject to standard shipping rates.
We can only ship to the U.S. (lower 48 states, Alaska, Hawaii, and Puerto Rico).
We know you’re excited to receive your gear and we’re stoked to get your gear out to you! Orders placed on BlueZoneSports.com will typically ship from our fulfillment stores within 1-2 business days.
In order to provide the best possible assortment on BlueZoneSports.com, we fulfill all orders from our chain of store locations. While this may reduce shipping times, this may result in portions of your order being shipped in multiple packages and/or having multiple delivery estimations.
We understand that many adventurers outside of the U.S. want to experience the BlueZone. Unfortunately, at this time, we are unable to ship packages internationally.
All bicycle orders placed on BlueZoneSports.com will be shipped via Bike Flights. Bike Flights is a 3rd party transit service we use to ensure your bike is delivered safely to you. This service will allow us to add insurance to your package and may require a signature upon delivery subject to your order total. Please allow 3-4 business days for your bike order to be processed. All bikes ship from our retail locations and are first assembled and inspected by our team of expert bike technicians, then repackaged and shipped to you. You will receive a separate email with your tracking information.
Please note that there are some bike brands that we cannot ship, however, we do have a pickup in-store option available.
Final assembly on all bike purchases MUST be done by a qualified bike technician. Failure to have the bike assembled by a qualified technician AND retain a copy of your labor receipt may void the manufacturer warranty and could result in damage and/or injury if not assembled correctly. Please note that as an industry standard, some bikes might have minor cosmetic blemishes due to the nature of shipping. Please report any damaged part that affects the safety or ride-ability of your bike immediately upon receipt.
Shipping information such as address changes are adjustable up until the time of shipping. Once your package has left our fulfillment store, you will need to work with the carrier to adjust the information.
Once you have placed your order, we cannot change the shipping method. Please make sure to carefully review your order before submitting to ensure you have selected the right shipping method.
If you have a gate code or special instructions for delivery, we recommend using the free delivery service options from UPS. These services will alert you of incoming packages, allow you to add delivery instructions, reschedule the delivery and more. These services are free to sign up, however, some features may incur a fee. For more information regarding these services, please see the link below.
UPS Ground shipping and UPS 2nd Day Air shipping time frames are only estimates. Transit times are out of our hands once your gear leaves our fulfillment stores, and we cannot guarantee the time frames of these shipping methods. View estimated UPS Ground transit days based on when your package leaves our fulfillment stores. Please note UPS is not guaranteeing delivery times and these are approximations only.
Need to cancel your order? We get it, things happen. If you need to cancel your order, please contact us at:
Please note that if you are cancelling an order that has already left our fulfillment store, a $20 package redirect fee may be subtracted from your refund.
To ensure your package is delivered to you safe and sound, we at BlueZone Sports reserve the right to require a signature at the time of delivery for any order. All orders over $250.00 will require your signature upon arrival. Please make sure to check your tracking status so you know when your order is expected to arrive.
Some people outside of the U.S. may use a package forwarder to get their gear abroad. Please be aware that BlueZone Sports and BlueZone Sports’ partners and vendors cannot be held liable for damage or costs that may occur after the package has been delivered to the shipping address provided at the time of purchase. If you plan on using a package forwarding facility, please contact us prior to placing your order.
We want to make sure you get your gear in time for your next adventure but there are some times of the year where we need to give our hard-working UPS workers an extra day or two. Please give your package a few extra days to arrive if you placed your order around one of these dates.
Please note that our fulfillment stores and corporate offices are closed on Thanksgiving and Christmas Day.
Holiday Shipping Deadlines: Orders selected with Standard Shipping must be placed by December 16, 2025, and orders selected with Expedited Shipping must be placed by December 19, 2025, to increase the likelihood of delivery by December 24, 2025.
These dates are based on carrier-provided transit estimates and apply only to in-stock items shipping within the continental United States.
Please Note: Delivery times are not guaranteed. Weather conditions, carrier delays, high-volume holiday periods, and other factors outside of BlueZone Sports' control may impact actual delivery dates. BlueZone Sports is not responsible for packages delayed in transit.
We recommend placing orders as early as possible to ensure timely delivery.
You will be emailed status updates as your order goes through the shipment process.
Your order status can also be found by following the steps below.
Once your order has been processed and shipped, you will be emailed a shipping confirmation email that contains your tracking number.
Tracking information can also be found by following the steps below.
At BlueZone Sports, we're excited to offer our customers a flexible and convenient way to finance their purchases with Credova. Credova is a Buy Now, Pay Later solution that allows you to apply for financing on any item over $150.00. To learn more about Credova, click here or contact us:
Need to return your item? Sometimes things just don’t work out. View our Returns and Exchange policy here.
For all returns, please ship to:
BlueZoneSports.com
Attn: Returns
2546 Precision Drive, Suite A
Minden, NV 89423
We stand behind our product and offer a 100% satisfaction guarantee. You may return new, unused items purchased from BlueZoneSports.com for a refund up to 60 days following the date of purchase.
Returned merchandise must be sent back in original and unused condition. All items must be returned in the condition in which they were received, including but not limited to manufacturer packaging, tags, documentation, and any accessories where applicable. All items must be free of any dirt, hair, fur, or other debris. For footwear, please make sure to try on all footwear on a clean carpeted surface to avoid any dirt, hair, wool, or other debris. If merchandise is not in re-sellable and unused condition, it may result in a restocking fee. Don’t worry, this is pretty rare, and it is a last resort on our end.
Ship your return:
To make shipping your return easy, we offer flat rate UPS Ground shipping labels. A $7.99 shipping cost will be deducted from your refund or credits issued for the return of your new and unused items.
For oversized items such as bikes, a $64.99 shipping cost will be deducted from your refund or credits issued for the return of your new and unused items. If you are unsure if your return qualifies as an oversized item, please contact us.
Once you have the UPS Ground return shipping label, print the label, and affix it to the outside of your return package. Drop it off at a UPS store of your choice and we’ll take care of the rest.
Contact us: returns@bluezonesports.com to get started with your return (please include your order number in the subject line).
BlueZoneSports.com
Attn: Returns
2546 Precision Drive, Suite A
Minden, NV 89423
For customers who have purchased items from BlueZone Sports through the Amazon Marketplace, it is necessary to sign into your Amazon account and request a return through the Amazon.com system.
To request a return through the Amazon Marketplace, go to “Your Account” on Amazon.com, click “Your Orders” and then click the “Seller Profile” link for your order to get information about the return and refund policies that apply.
Make sure to package the merchandise you are returning correctly.
All merchandise should be returned in a proper shipping container such as a box, shipping pouch, or other container that protects the merchandise during transit.
Your refund will be initiated within 2 business days after your return arrives to our distribution center. Initial shipping costs are non-refundable.
Refunds will be issued to your original form of payment. If the original payment is no longer available, we will issue your refund in the form of a BlueZone Sports eGift Card for the refund amount. You will receive a confirmation email once your return has been processed.
Depending on your banking institution, please allow 3-5 business days for your refund to reflect on your credit/debit card.
In-store purchases can be returned to any of our BlueZone Sports locations. With a receipt, you may return new, unused items in-store for a refund up to 30 days following the date of purchase. All items must be in the original retail condition, including but not limited to manufacturer packaging, tags, documentation, and any accessories where applicable. All items must be free of any dirt, hair, fur, or other debris. For footwear, please make sure to try on all footwear on a clean carpeted surface to avoid any dirt, hair, wool, or other debris.
Used items with receipt and tags can be returned within 10 days for store credit only.
For in-store purchase returns, please ship to:
BlueZone Sports
Attn: Returns
2546 Precision Drive, Suite A
Minden, NV 89423
Unfortunately, there are times where we cannot return your item. Please see below for a list of items that are final sale and non-returnable.
If you feel that any item you have received is defective, please contact our customer service department for assistance on your item’s warranty.
Please contact us with any additional questions concerning faulty merchandise.
Received a damaged or incorrect item? Contact Customer Care
