My high-range gravel drivetrain · g/ianguid/
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My high-range gravel drivetrain

I recently came to the sad conclusion that gravel 1x setups are for fit people only, given that I am simply incapable of climbing any steep incline with a 40t front, 46t rear gear.

My gravel bike has a SRAM Rival 11-speed mechanical drivetrain – both brakes and derailleur – which tops at 46t max.

A quick Google search revealed a hack that would allow me to bring the range of my drivetrain to mountain bike-levels quite easily: get an Eagle NX derailleur lower cage, and slap it onto your SRAM road derailleur1.

The theory says that all it is needed to increase cassette range on the climbing gears is having a derailleur cage that allows the chain to wrap around the biggest cog – the standard Rival cage isn’t big enough for 50t, but Eagle ones are.

For this hack, the Internet suggests a Shimano Deore 50t 11-speed cassette – I wanted to also shave off some weight so I went for a Sunrace one… but with 51t on the biggest cog.

This choice might seem odd, but I figured since Eagle is designed to work with 52t cassettes it should work alright.

As for the chain I tried a KMC 11-speed specific chain but I didn’t like the way it rubbed against the cassette cogs, so I pivoted towards a SRAM 11-speed one.

While I waited for the cassette and chain to arrive, I modified my Rival derailleur as described, stealing the lower cage from an old NX one I had taken off my Transition Scout.

Parts arrived, mods done and… it didn’t work.

Or better, it didn’t work as well as I expected – in particular, getting the chain to go up the 51t cog and staying there was very difficult.

Setting the B-screw and chain tension was a nightmare, the cassette was so noisy not even the tire’s road buzz would distract me from hearing it.

After spending a total of 4 hours trying to get it work correctly, I ended up on a “good enough” setup that only lasted until the derailleur cable stretched enough to warrant a barrel adjuster turn, which completely destroyed shifting again.

One day, a random thought: I decided to try my luck with one of those derailleur hangers extenders2.

I figured lowering the derailleur a few millimeters would help chain retention and overall shifting quality.

The extender arrived and right off the bat it didn’t inspire much trust: it was made of flimsy aluminum, bolts included.

Apparently this fixed all the issues I had!

Setting up the derailleur now is a breeze, shifting is fast and smooth, and the drivetrain is not noisy at all: success!

As a treat to myself I also got one of those shiny aluminum derailleur cage and jockey wheels off Aliexpress3, which turned out to be Garbaruk replicas: shifts even better, looks much better.

I’ll buy the real deal in the future, but for now they stay on.

Before venturing in this drivetrain shenanigans I looked at the price of a modern Shimano GRX 12-speed hydraulic setup: depending on the shop of choice, between 1000€ and 1200€.

This mod pretty much solves all the range problems a new GRX 12-speed would’ve solved, but for a much lower total cost:

  • SunRace 11-speed, 10t-51t, “lightweight edition”: 120€
  • Replica Garbaruk jockey wheels and derailleur cage: 45€
  • SRAM 11-speed chain: 10€

Much better!

Money shot of my gravel bike.

  1. Funny thing about their product is they tend to keep the same spacing, sometimes even standards and tolerances, across their product range. ↩︎

  2. Everybody have random bike-related thoughts right? ↩︎

  3. I’m re-evaluating my position on this: there’s a lot of cheap crap being sold on Aliexpress, but if you dig deep enough you can find great piece of engineering at a very competitive prices. ↩︎