Upgrade your trail drivetrain with the DEORE XT Di2 M8250 Upgrade Kit, an easy upgrade kit that delivers precise, lightning-fast shifting with next-gen wireless simplicity. Built around Shimano’s M8250 Derailleur, this kit is optimized for rugged trail riding, offering high-impact durability, automatic recovery after hits, and a streamlined wireless setup that keeps your cockpit clean and your rides smooth.
The RAPID ES M8250 shifter offers intuitive, customizable control with adjustable paddles, tactile feedback, and programmable multi-shift options, all accessible through Shimano’s E-TUBE PROJECT app. Powering the system is the compact BT-DN320 battery, protected inside the derailleur yet fully removable for charging with the included EC-EN100 charger.
Whether you're dialing in your trail bike or building a lightweight XC setup, this Di2 kit delivers Shimano’s hallmark reliability with the most advanced wireless shifting experience yet.
Kit Includes:
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XT M8250 Rear Derailleur (Choose Medium or Long Cage)
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XT M9850 Di2 Wireless Shifter
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Shimano BT-DN320 Di2 Battery
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Shimano EC-DN100 Di2 Battery Charger
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1x Shimano Quick Link
Features:
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Wireless Precision: Clean cockpit and instant shifts with wireless Di2 control.
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Auto Recovery: Derailleur returns to position after impact for worry-free trail performance.
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Trail-Ready Durability: Reinforced plates, shielded pulleys, and added ground clearance.
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Custom Control: Ergonomic shifter with programmable shift modes and a third button for added functions.
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Efficient Power: Battery lasts up to 340 km on a single charge with energy-saving tech.
Specs:
Derailleur
| Model: | M8250 |
| Model ID: | RD-M8250-GS (Mid Cage) RD-M8250-SGS (Long Cage) |
| Shift Technology: | Wireless |
| Communication Protocol: | Di2 |
| Max Tooth: | 38t |
| Drive Config: | 1x |
| Weight: | TBD |
Shifter
| Model: | M8250 |
| Model ID: | SW-M8250-R/IR |
| Shifter Type: | Wireless |
| Clamp: | 22.2mm bar clamp, I-SPEC EV |
Compatibility
The Shimano XT Di2 M8250 Upgrade Kit is 100% backward compatible with previous generation Shimano 12-speed cassettes, chainrings (cranksets), and chains. Compatible models include: XTR M9100 and M9200, Deore XT M8100, SLX M7100, and Deore M6100.
Medium cage derailleurs are compatible with 45t cassettes and long cage derailleurs are compatible with 51t cassettes.
The XT M8250 Upgrade Kit is compatible with the following:
| Frame: | Modern framesets via a derailleur hanger, including the Universal Derailleur Hanger (UDH) |
| Cassette: | Shimano HG 12-Speed: 9-45t, 10-45t (Medium Cage - GS), 10-51t (Long Cage - SGS) |
| Shifter: | XTR M9250 |
| Chain: | 12-speed HG: XTR M9100, Deore XT M8100, SLX M7100, Deore M6100 |
| Battery: | BT-DN320 |
Please reach out to us with any questions you may have on anything we sell. We want to make sure you get the right items the first time. Our lifelong riders at Thunder Mountain Bikes are knowledgeable and would love to talk to you!
Shipping
We currently offer both economy and expedited shipping options through FedEX and USPS.
Most orders totaling over $59 are eligible to ship for free via an economy ground option of our choice.
Due to larger box sizes, handlebars and other oversized items will have an additional shipping fee.
Most bikes ship free within the continental US. Bike shipping to AK, HI, or PR is available at an additional charge depending on the exact delivery location.
If you're in need of something super-quick, please contact us directly. We may be able to overnight your order with an additional fee depending on your location.
RETURNS
Should there be an issue with the item you bought, or you no longer need your purchase, we will be happy to set up a return.
Component & Gear Returns
Returns may be requested within sixty (60) days of the delivery date. All returned items must be received in new, unused, and uninstalled condition, with the original tags and labels attached and in the original packaging. We cannot accept returns on any items installed or show wear of any kind.
Bike Returns
Returns or exchange requests for bikes must be requested by emailing us at sedona@thundermountainbikes.com within fifteen (15) days from the date of delivery. Bikes must be in un-ridden condition. Custom-built bikes may not be returned. Returned bikes have a $200 restocking fee and the customer pays for return shipping.
Return Shipping
Customers may choose to use our provided flat-rate return shipping label at $9, or choose a carrier of their choice to handle their product return.
The $9 flat rate label will be deducted from the refund issued for the return. You can either print this label after requesting a return from the Order History in your Account profile, or you can request that we email you the label.
For all other return shipping methods, please email us at sedona@thundermountainbikes.com after submitting your return request so that we can confirm the shipping information you should use to return your item(s).
REFUNDS
We will process your return after we receive your returned item(s) and inspect the condition. Please allow at least seven (7) days from the receipt of your item to process your refund. We will notify you by email when your return has been processed.
EXCEPTIONS
If you receive defective or damaged products or if we sent you the wrong products, please contact us using the phone number or email below.
RETURN PROCESS
To request a return, please log in to your customer account by clicking the 
Profile icon in the top right of any page or visit account.thundermountainbikes.com.
1. In the Email field, enter your email address and click Continue.
2. In your email account, open the email sent from our store and copy the six-digit verification code included in the email.
3. Go back to the online store and enter a six-digit verification code to log in.
4. Find and click on the order you want to submit a return for.
5. If your order has more than one item, select only the items you want to return.
6. Select a return reason and add a note for the store if needed.
7. Click Request Return.
Once your return request is approved, you will receive an email with shipping instructions and a return shipping label.
QUESTIONS ABOUT RETURNS?
If you have any questions concerning our return policy, please contact us at:
