A SRAM Eagle hack deliver business up front, party in the back. We’ve discovered how you can build a #BudgetMullet SRAM drivetrain for your adventure gravel bike, thanks to an insider tip from Parallel Handbuilt, a bike shop in the Netherlands. All you need is your current mechanical SRAM 1x drivetrain, a new Eagle derailleur, a few standard tools, and a little bit of patience. Then your dropbar adventure gravel bike will be ready for up to a 52T cassette!

How To: Parallel Handbuilt BudgetMullet dropbar Eagle 1×11 hack

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion
c. Joergen Trepp

Mullets, the same idea behind mixing 27.5 & 29″ MTB wheels and mixing MTB rear derailleurs with road cranks & shifters on gravel bikes. You get fast-moving efficiency up front and technical trail-capability in the back. It’s one of the reasons that the newest SRAM AXS wireless groups are so interesting, pairing Red/Force AXS dropbar shifters with XX1/X01 Eagle MTB Derailleur. But all that wireless 1×12 drivetrain options are still gonna cost you at least $1400 just for derailleur, levers & cassette. And you need to keep everything charged. Not exactly the best option for remote bikepacking.

So, is there a better way?

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

Enter the #BudgetMullet SRAM Eagle hack. After some digging and measuring, Joergen Trepp of Parallel Handbuilt figured he’d try to make an Eagle derailleur work with his Rival1 shifters. Instead of aftermarket cages of leverage ratio gadgets, he uncovered a cheaper & easier solution, all the while sticking with original SRAM parts.

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

The secret is the cable fin. That’s SRAM’s name for the small curved cable guide that directs the derailleur wire into the pinch bolt. That simple & replaceable part on all modern SRAM MTB & CX 1x rear derailleurs also happens to determines the cable pull, and swapping it can convert a regular X-Horizon Eagle MTB derailleur into an 1:1 Exact Actuation Eagle road pull derailleur.

But Why?

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

The biggest cassette cog supported by the Force 1 derailleur is 42T, but swapping to a GX Eagle derailleur extends that up to 52T. Joergen is headed off to ride the Atlas Mountain Race next week, lugging a loaded bikepacking bike over the Atlas mountains in Morocco. And he wanted a wider gearing range (without resorting to a 2x) to crawl up steep off-road climbs, while not just spinning out on the descents & flat sections of the 1145km long self-supported race.

Let’s talk compatibility

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

This hacked conversion requires a mechanical SRAM 1x road/cross/gravel rear derailleur to donate its cable fin. Likely, you already have this on the bike to start. If not, find someone who has broken one. (SRAM does not currently sell it as a spare service part.) Only Force 1 & Rival 1 are compatible, as their cable fin is clipped/bolted-on. With a steady hand, you might be able to drill out the rivet on a Apex 1 derailleur, but that’s on you if you try.

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

As for the replacement MTB derailleur, you will need an XX1 Eagle, X01 Eagle, or GX Eagle rear derailleur. NX & SX won’t work since the rivet the cable fin on, and so you can’t really reinstall the donor fin.How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

 

Then, you are going to need a new 11-speed cassette to get the most out of this conversion. Remember, the shifter determines how much & how many times the cable gets pulled with each shift, so you still end up with a 1×11 setup. Since SRAM doesn’t do an 11-speed cassette bigger than 10-42 or 11-42, you need to look elsewhere. Any big 11-speed cassette should work, but be according to Joergen, “beware of chain length when using small cassettes with an Eagle derailleur.”

His ideal choice is a Sunrace 11-50t cassette for its simple setup. TRW Active also offers an 11-speed 11-52T cassette, a colorful Garbaruk 10-50/11-50T, or OneUp used to have a 50T Shark conversion for a Shimano 11-42T cassette if you happen to have one of those still laying around. And if you want the most range, look no further than the eThirteen TRS Plus 9-46t.

Here’s where the hack begins and we remind you that this is not authorized by SRAM, and is likely going to void your warranty. Now, let’s do it!

Step-by-step: Hacking your BudgetMullet Eagle derailleur

SRAM Eagle hack instructions, as provided to us: 

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

Step 1: To remove the cable fin’s, remove the small circlip holding the fin using pointy tweezers or an actual circlip tool. Avoid using a flathead screwdriver as it may bend the circlip (you need to reuse it).

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

Step 2: Once the circlip is removed, loosen and remove the cable pinch bolt. Now you can lift the cable fin off of the derailleur.

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

Step 3: Swap the shorter Exact Actuation cable fin onto the Eagle derailleur. Follow these instructions in reverse to install the cable fin again.

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

For bonus points you can also replace the cable wheel on an Eagle derailleur with the barrel adjuster from a Force1 derailleur, however [Joergen] prefers to go without and place an inline barrel adjuster near the cockpit for on-the-fly adjustments.

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

Step 4: Go ride you newly Eagle-equipped dropbar bike on an adventure, confident in the fact that you just managed to hack together your own #BudgetMullet setup. And you avoided buying a bunch of expensive new wireless AXS components, working with a lot of what you already had mounted to your bike.

How To SRAM Eagle gravel 1x 11 speed drivetrain hack, Parallel Handbuilt BudgetMullet drop bar wide range adventure bike 1x11 drivetrain conversion

One last thanks to Joergen Trepp and Parallel Handbuilt in Rotterdam, The Netherlands. If anyone at SRAM asks, we don’t know him, he doesn’t know us, and we don’t know what you are talking about.

53 COMMENTS

  1. I did this three years ago to a tandem bike, I posted it on World Bicycle Mechanic Forum. 20 minutes later SRAM called me and asked me to remove the post alleging what I did was not going to work. I removed it but I’ve been mad at SRAM since then.

  2. This has to be one of the best posts from this website in some time. Great! Now I want the hack to turn my 11 speed SRAM brifter into a 12 speed one and the goal will have been reached.

  3. Or for brevity’s sake, just take the cage from the GX, graft it on to the road derailleur and be good with that. As long as you have the same type clutch on each derailleur, it’s a lot quicker and less hassle taking every smaller part to graft onto the eagle derailleur.

  4. “And if you want the most range, look no further than the eThirteen TRS Plus 9-46t.”

    What’s weird about this article is this sentence above, because all the 11sp SRAM long-cage 1x derailleurs are already compatible with this cassette without having to cannibalize them to mod a 12sp mtb derailleur.

    If the goal is to increase the gearing range of a bike with 11sp dropbar levers, then logic would dictate that just buying am eThirteen cassette would be cheaper than destroying an 11sp and then buying a new 12sp Eagle derailleur AND a cassette.

    The only way the hack described in this post could be cheaper is if your existing rear wheel was HG and not XD-compatible. In this scenario, we are assuming that the freehub body is not convertible to XD and that you would have to replace the whole rear wheel with one that can take an XD cassette like the eThirteen. So, yes, you would need to replace the derailleur a 12sp unit that has a larger max cog spec, to fit an HG cassette with a 50T-ish max cog…….and then you would need to hack that derailleur to work with the 11sp road lever pull-ratio.

    I guess you could argue that you prefer the gearing jumps of SunRace, TRW Active, Garbaruk, or whatever…..but at that point you are raising a white flag on the “cheap hack” argument.

    But hey, why should Bike Rumor vet anything it posts when the comments are the reason they get traffic?

    • But hey, you think bikerumor has to bait know-it-all-bike nerds into making verbose “well actually” posts, like yours, that contribute nothing? You guys do this all on your own. This is clearly useful information for people that are interested in combining parts they have laying around.

      • Padrote:
        Well, actually, I am a professional bike nerd, and unfortunately a fair bit of my shop time is taken up by explaining to customers why what they “read online” is wrong and/or totally irrelevant to their needs. In fact, I literally just had a 45min conversation with a customer to shoot down what the internet AND another bike shop said.

        Snelbroek:
        1) Ok, the hack does not “destroy” per se, merely renders the donor derailleur inoperable indefinitely. No difference in cost on the front end.
        2) I had not noticed that eThirteen had discontinued their 9-46 11sp cassettes. It’s not like I sold a lot of them, but it is disappointing that I no longer have that option. BTI still has a few in stock though FWIW.

    • Exactly, that 9-46 cassette works great with a Rival 1x system, I ran one myself all last year, everything else was standard Rival 1x.

      • Hi GT – that is good to know. I run my bike packing bike on Rival 1 and 11-42 – so I can change to 9-46 without problems. Officially SRAM Rival goes only till 42. But I guess it works with 46 too. Did need to adjust the derailleur? Also, did you have to change chain length? Thanks.

        • If you keep the same size chainring I think you’ll probably need a longer chain. Because I went from a 10-42 (IIRC) to a 9-46 I think I changed the chainring too, and I believe I went with a new chain, though I don’t know if it was a different length.

          I did definitely have to adjust the “b screw” on the rear mech, if you don’t it either won’t shift well or won’t shift into the 46 at all.

    • 1. You don’t destroy any derailleurs with hack if you’re using rival/GX and above.
      2. The ethirteen cassette gas been discontinued, but the concept remains the same with another 50t cassette or expander ring.

    • Came to post this. Contrary to the comment below, e*Thirteen does still make a 9-46 cassette (I just bought one) and it doesn’t destroy any derailleurs (it works beautifully with my Force1 setup). But if you don’t believe me, just ask e*Thirteen.

      • Hi Nathaniel , that is good to know. I run my bike packing bike on Rival 1 and 11-42 – so I can change to 9-46 without problems. Officially SRAM Rival goes only till 42. But I guess it works with 46 too. Did need to adjust the derailleur? Also, did you have to change chain length? Thanks.

  5. This is a great hack and an excellent, detailed article. Yes, similar setups could be done before, but this gives yet another option to us tweakers, and simplicity of the final setup is refreshing. Thank you, BikeRumor!

  6. @Blake I believe you mis-understand. Pulley cage length does not in itself increase cassette capacity, it mearly adds to the derailleurs ability to manage chain length. Upper pulley position and derailleur geometry is what dictates cassette clearance.

  7. Rus from Paths less Pedalled on youtube did this in his cave of bad ideas series in december I think. Check there to see him go through the whole process

  8. Paul Components makes a Sram Shifter Adapter that allows one to mount the Eagle thumb shifter to a standard road bar. I paired the Eagle set up with TRP’s Hylex RS brakes to complete the group. Rode that for over a year till I went to the AXS mullet. It worked fine.

  9. I run a Shimano ultegra 34t cassette with 32×20 chain ring. Low as an eagle can fly. 2x yes though It’s hydro brakes and can easily get lower with the xt 42t cassette if i ever wanted to pedal in place.

    • Many frames cannot run their maximum tire size with a 2x system, many 2x systems are not durable enough for intense off-road situations/mtb’ing unless your name ends in van der Poel.

      But otherwise, yes, 2x systems offer better cassette jumps and in general a larger range for touring, no questions there.

      • What 2x crankset that can run 20-32 chainrings are you thinking of that isn’t “durable enough for intense offroad situations”?

  10. Thx for sharing this information. Had three Sunrace cassettes running and swapped two if them for Garbaruk ones. Much better build quality and shifting is world’s apart.

  11. This is all very nice but completely unnecessary. Garbaruk 10-50 cassette works perfectly with Force RD – just need to change the cage to the one that comes with the cassette. I put 10k km on this combination including SRMR. Shifting was perfect.

  12. 12 speed 11-42 (or 10-36) and 11-36 cassettes would be very desirable for the more road oriented 1x cycling. No idea why SRAM haven’t made a 1×12 mechanical. What are they waiting for? I don’t want to recharge my gears, carry spare watch batteries and faff with my phone to ride my bike. 1x is meant to be simpler not harder.

  13. Instead of sacrificing a derailler for its donor fin, such a fin could easily be 3D-printed, given that someone models one. They could sell for less than a buck each this way.

  14. if only it is possible to buy it somewhere 🙂

    PS cage replacement solves the same problem (if only it is possible to buy somewhere) 😀

  15. Great hack.

    I run a 32×42 on my gravel bike. Force 1 rear mech and force 11spd shifters with TRP sypre SLC no faff brakes.

    How often you really need to pedal on gravel descents or any descent when touring or exploring? I use the DH to get out of the saddle and have a bit of a stretch.

  16. I’ve just simply run a (poorly named) road link by wolf tooth, drops the derailleur down 1cm to allow the guide wheel to clear the larger cogs of mtb cassettes. I was worried re shift performance but done on two bikes now and its been awesome. ive also been able to run up to a 50t by replacing ghe guide wheel with a smaller 10t guide wheel as above 46 even on max b-tension an 11 or 12t guide wheel wont clear, but 10t does. This method leaves you with amazing range, still great shifting, and no voidance of warranty. Thanks wolf tooth. Last cx / gravel bike (Trek boone) and new cx / gravel bike – i run 11-42 for cx and 10-46 (garbaruk cassette) for gravel events, all i need to do between the two cassettes is a couple turns of b-tension adjust screw to allow clearance for 46t, a couple turns back again when put 42t back on to ensure crisp shifting, and voila, all the range i need and no taking apart derailleurs and voiding warranty. My bikes have been shimano equipped so the above hack wouldn’t have worked, however that led me to simply find the road link solution, and its been happy happy days for years since.
    *Note officially the road link is to extend road derailleurs to take up to 40t cassettes, but i have found using on road long cage derailleurs up to 46t has been no problems – shifting has been brilliant – at least with my shimano equipped bikes)
    https://www.wolftoothcomponents.com/products/roadlink

  17. I love this, it makes me laugh inside, the demise of the front derailleur has people trying to find more appropriate gears rather than having 2x and gears to do everything, with out having to swap stuff around for ages in the workshop, I love tinkering but I love riding more,, 2x on road gravel touring makes so much sense, other you just spend all your time looking for the right gear, and it’s either too small or too big. You don’t see the pro’s on the road running 1x for proper days out?

  18. Great post, more of these please!

    So to my understanding this does the same as Jtek Shiftmate 9, just more elegantly and possibly cheaper if you’re lucky to find a broken derailleur from someone who is willing to give away the fin.

    My question is, would this work equally on a 11 speed MTN draillerur?

  19. You can get all this options since couple of years from Stock-Rennsporttechnik in Germany. they have Sram roadshifters for use every cassette thats available on the world, up to 13 speed. 1×12, 1×13 , 2×13 . there you can get upgradekits or complete sets. great and cheap.

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