Deore XT 1 x 12 Groupset
Deore XT 1 x 12 Groupset

Deore XT 1 x 12 Groupset

SKU: M8100Group165-30t45t

Regular price$614.94
Cranks (Model/Length/Hub/Chainline)
Chainring Teeth
Cassette Range
  • Low stock - 1 item left
  • Inventory on the way
  • Free shipping on all orders $49+

The Shimano Deore XT Groupset is the original trusted mountain bike groupset, beloved by mountain bikers worldwide. No matter the trail or ride, XT delivers reliable shifting, superior braking, and easy maintenance. Engineered for high performance, this groupset is a dependable workhorse for all your mountain biking needs.

Shimano Deore XT Groupset Includes:

Shimano Deore XT M8100 Series Crank Arms

Model: Hub Spacing: Chainline: Q-factor: Weight:
FC-M8100 135/142mm or 141/148mm (Boost) 52mm 172mm 620 grams
FC-M8120 141/148mm (Boost) 55mm 178mm 628 grams
FC-M8130 157mm (Superboost) 56.5mm 181mm 636 grams

Shimano Deore XT SM-CRM85 Chainring

  • Available sizes: 28t, 30t, 32t, 34t, 36t

Shimano CS-M8100-12 Cassette

  • Cogs: 10-45t: 10-12-14-16-18-21-24-28-32-36-40-45
  • Cogs: 10-51t: 10-12-14-16-18-21-24-28-33-39-45-51
  • Freehub Interface: Microspline
  • Average Weight: 10-51t: 470 grams

Shimano SL-M8100-IR Shift Lever

  • Mount: I-SPEC EV
  • Max Multiple Shifts: 4
  • Shifter Type: Rapidfire Plus
  • Average Weight: 120 grams

Shimano RD-M8100 Rear Derailleur

  • Cage Length: SGS/Long
  • Max Low Sprocket: 51t
  • Min Low Sprocket: 45t
  • Pulley Size: 13t
  • Average Weight: 284 grams

Shimano CN-M8100 Chain

  • # of Links: 138
  • Roller Link Plate: Sil-Tec
  • Quick Link included

Please reach out to us with any questions you may have on anything we sell. We want to make sure you get the right part the first time. Our lifelong riders at Thunder Mountain Bikes are knowledgeable and would love to talk to you!


We currently offer both economy and expedited shipping options though FedEX and USPS. 

Orders totaling over $49 are eligible to ship for free via an economy ground option of our choice. 

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 and depending on your location. 


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.

Returns or exchange requests for New or Used Bikes must be requested by emailing us at 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.

Returns for most other items 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. 

Clearance and open-box items may not be returned. 


To request a return, please log in to your customer account by clicking the  customer account icon  Profile icon in the top right of any page or visit

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 that 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. 


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.


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.


If you have any questions concerning our return policy, please contact us at:

(928) 282-1106   |

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