About The Shimano GRX RD-RX825 Di2 12-Speed 2x Long Cage Clutch Black Rear Derailleur
The Shimano GRX RD-RX825 is a 12-speed Di2 gravel derailleur for 2x drivetrains, with a built-in wireless unit and charging port. Shadow RD+ with an ON/OFF switch keeps the chain quiet on rough terrain.
It works with 11-34t and 11-36t cassettes, has 40t of capacity, supports Full or Semi-Synchronized shift modes and uses Shimano rear direct mount.
Who It's For
- Gravel riders on GRX Di2 2x12.
- Riders replacing an RX825.
- Not for mechanical shifters.
What to Look For
- System: Shimano road Di2 12-speed.
- Cassette: 11-34t or 11-36t.
- Mount: Shimano rear direct mount.
Key Features
Integrated wireless and charging. Compact design with switch and port built in.
Gravel-tuned clutch with switch. ON for gravel, OFF for smooth roads.
Synchro shifting. Full or Semi-Synchronized modes.
Rider Intent Summary
- Biggest strengths: Di2 gravel shifting with clutch control.
- Tradeoffs: Di2 only; 36t max.
- What makes it different: GRX's electronic 2x derailleur.
Victory's Take
We build GRX Di2 for gravel riders who want electronic precision. Victory Bicycle Studio can install and configure it.
Specifications
- Brand: Shimano
- Model: GRX RD-RX825 Di2
- Drivetrain speeds: 12
- Drivetrain: 2x
- Top sprocket: 11t
- Low sprocket: 34t–36t
- Chain wrap capacity: 40t
- Cage length: Long
- Mount: Shimano rear direct mount
- Shifter compatibility: Shimano road Di2
- Color: Black
- Part number: IRDRX825A
What you get

Shimano GRX RD-RX825 Di2 12-Speed 2x Long Cage Clutch Black Rear Derailleur
Frequently Asked Questions
How is the bike packaged and how long does delivery take?
All bikes are securely packaged to ensure that damage doesn't occur during shipping. All parts of the bike are padded and if needed, zip tied to minimize or eliminate movement inside the box. Once a bike is handed to the shipping company (usually Fedex or UPS), depending on your location, delivery will range from 1 day to 8 days. If you do choose the option for Professional Assembly or White Glove Delivery, this can add anywhere from 2 days to 5 days to the lead time.
Can I finance the purchase of my new bike?
Yes. Simply select the Shop Pay Installments option which will allow you to buy now and pay later. Shop Pay Installments is powered by Affirm. If you would like to determine your spending limit, simply download the Shop app or the Affirm app on your smartphone and after you create an account on one of these apps, the app will let you know what is your spending limit.
Can I return the bike if it doesn't suit my needs?
Our return process is as follows. The customer is responsible for the return label ($150). Once the returned bike arrives at our warehouse, our team will inspect it and make sure it is in new condition and undamaged. Once we verify, we will process the return and issue a refund to the original payment method on file. To clarify the amount refunded, it would just be the amount of the bike (and tax if applicable) less the $150 shipping label that we provided, but the original shipping is not refunded. So if the original bike cost $4,500 and shipping was $150 (so you paid $4,650), you would be refunded $4,350 (the $4,500 less $150 for the return label) assuming the bike was returned in new and un-used condition and within the 30 day return period.
What does the warranty of my new bike or product cover and what is the warranty period?
Depending on the bike or any product, different companies have different warranty policies. If you do ever have an issue with your bike or any product, simply email us at online@victorybicyclestudio.com and we will assist with any warranty issues and clarify the warranty for the affected product.
Can I have my bike serviced at any bike shop?
Typically, to avoid any issues with your warranty, you should bring your bike to a certified mechanic or bike store for that bike (i.e. if you have a Trek bicycle, you should bring the bike to be serviced to a local bike store that is an authorized Trek dealer). If you need assistance, simply email us at online@victorybicyclestudio.com and we can direct you to a certified dealer of your bike.
Do you ship bikes internationally?
We unfortunately do not ship bikes outside of the 48 contiguous states of the United States. We do recommend for international customers to open (or use a current account) account with a freight forwarding company. If you use a freight forwarding company located in the U.S., make sure to put your billing address for a dedicated credit card as the same address as the freight forwarder so that you don't have any credit card or payment method issues).
Once you do this, simply place an order with us and we can ship to the U.S. address as long as the credit card doesn't get rejected. Once the freight forwarder has the box/order/shipment, you would instruct them to then ship to you in your home country and they would charge you their own shipping charge to ship to your international address.
Do you offer free shipping?
We do offer free shipping on non-bike orders over $100. We do not offer free shipping for bicycles unless it is a one time promotion. Generally, bike shipping will cost $150 and that covers just the shipping of the bike with no assembly. If you were to bring that bike to your local mechanic or bike store, you would pay them their assembly fee. If you choose our Professional Assembly option for $200, our service technicians would assemble the bike before shipping and then re-pack the bike safely for transit. When you receive the bike you would attach the front wheel, attach the seatpost/saddle, and raise the handlebars and clamp them. Those three items do have to be detached to minimize or eliminate the chance of damage in transit.
How much does shipping cost?
For orders of parts, accessories, apparel, etc. on orders under $100, shipping is a flat rate of $9.99. Regular bike shipping without assembly is $150, bike shipping with Professional Assembly is an additional $200 (so $350 in total which includes the $150 of regular shipping). Our White Glove Delivery option is $699 and that will cover the assembly of the bike and our White Glove Delivery partner delivering your dream bike to your front door, ready to ride!
How can I track my order?
When you place your online order, you will receive an instantaneous email update with your order number and order details, and shortly after, you will receive a follow up order email with the tracking number for your order. If you still need assistance with your order, feel free to email us at online@victorybicyclestudio.com and we will respond asap.
What happens if my package arrives damaged?
If your package arrives damaged, email online@victorybicyclestudio.com with pictures of all angles of the box and pictures of the damaged product and we will work with you to either send a new replacement asap and coordinate return (or re-imburse you for labor or costs incurred to fix the issue at your local bike store).
Are pedals included with the bike?
If you do not see pedals in the bullet point product specs on the product page, the bike does not come equipped with pedals. Many manufacturers do not spec bikes with pedals, so they are often purchased separately.
If I only pay the $150 for bike shipping, can I assemble the bike on my own?
Victory Bicycle Studio highly recommends that you bring your bike to your local certified bike store for the brand of the bike that you purchased. If you do attempt to assemble the bike and damage occurs, this may result in your warranty not being honored. For that reason, we do highly recommend to select our Professional Assembly option for $299.