Do I need a Goat Link on a Triban RC520?

Question

I would like to build a 1x road bike with low gear ration for bike touring. I went across this article about mullet drivetrain and it looks like what I want.

The Triban RC520 from Decathlon seems like a good condidate for a mullet drive. The modification I think would be the easiest would be

• Switch derailleur for Shimano GRX RX812
• Add WOLF TOOTH GOAT LINK
• Switch cassette for a SUNRACE CSMX80 11-50T
• Switch crankset for Shimano GRX RX600 40T
• Remove front derailleur

But the derailleur hanger looks weird (too long) to me on picture below (left) compared to a hanger looking more like I am used to (right). But on the right picture, the derailleur is installed with an additional part (that seem to be stock coming with the derailleur according to Shimano website pictures). As the goal is indeed to increase the length of the derailleur's arm (center pic), would it be necessary to add a Goat Link to increase the biggest cog possible to 50T on the GRX RX812 ?

And if yes, could I install the Goat Link on this derailleur hanger ?

Left: Triban RC520's derailleur setup. Center: Example setup with Goat Link, GRX RX812 and 50t cassette. Right: Another example with same Shimano 105 derailleur as Triban RC520.

Answer 1

Thats a direct mount, you need a roadlink-dm, not a goatlink.

https://www.wolftoothcomponents.com/products/roadlink-dm

Following is not scientific, personal opinion bordering on rant...skip, ignore or refute at your leasure.)

Why 1x road? The big push for 1x comes from frame design and freeing up space around the highly stressed Bottom bracket for squishies, followed closely by cost reduction, followed by marketing convincing people to 'upgrade' to a new bike that is less fit for purpose than the old one was with the obvious "my god, that bikes sooo..... ollllddd....., its got twwwoooo chain rings...." (Oh, and orthopedic surgeons looking to preserve their annual income for the next decades with knee replacements from cyclists not having a low enough gear.") For touring where you can be heavily loaded, you need the low gears, but not at the expense of high gears. MTB's and less so gravel bikes are prepared to sacrifice high gears for the benefits of 1x, I do not believe the 1x benefits out weight the loss of gear range for touring. While Goatlinks have been around a while, they came from a time when 1x was beneficial, but only in the most expensive group sets, and opened up 1x for a lower cost, but with drawbacks (reduce shift performance, especially once drive train was no longer brand new). If you still want wide range on anything that used on roads, IMHO 2X is still the way to go.

If you still want wide range 1x after skipping or reading my rant, have you looked at Microshift XLE 11 Speed, they do a Dynasys11 compatible drop bar shifter. The Microshift rear derailleur has a 46 max big cog which might be enough range for you.

Answer 2

Not an answer from the specific question, but one of the question in the introduction (too long to be a comment).

In short, you want to buy a road bike, replace the drive train by a very good gravel drive train, but with an accessory than may negate the benefit of this very good drive train. Parallelograms of rear derailleurs are designed for some cassette dimensions, goat links (or equivalent) may be useful to make sure that the derailleur can manage a very large cassette, but as result, the jockey wheels are too far from the small sprockets and the shifting performance is horrible (I tried — 11-42 cassette on a derailleur rated for 36T max).

You also state in the comments that you don't need more than 36/11, and never go faster than 30km/h. The aerodynamic advantage of a road bike is then pointless.

With the same budget, my recommendation would be start from a gravel bike with a Microshift Advent X drivetrain - that supports 11-48 cassettes (Cannondale Topstone 4, Bombtrack Arise SG, Marin Gestalt X to give some names), and replace the tires by road tires - or slick gravel tires for additional comfort. If you want a more aggressive position, bikes usually have spacers between the frame and the stem, that can be moved, precisely for that reason. If it's not enough, there is the option to replace the stem with a negative angle.

Advantages of this proposition:

• you have a series of components that are designed to work together, as intended.
• if you ever fancy the idea of gravel biking (which in Switzerland is fantastic), you can just replace the road tires by the stock tires - a road bike frame won't have the clearance for proper gravel tires.
• for touring, gravel bikes often come with many mounting points for luggage, while road bikes typically come with none.