SRAM 1x13 Mechanical Group

Hey guys, check out my latest video where I install a very cool 1x13 Sram hack. What do you think? Pointless or something to consider?



I like the idea of this!

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I guess it’s neat. But that is a lot of work and expense and lost watts (chain angle, smaller chainring, 10T) to still be compromised compared to 2x11 GRX. There are benefits to 1x for MTB, but for my bike that does triple duty as road bike, gravel bike and drop bar MTB I just use 2x11 GRX and don’t have to modify anything.

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Great video, Billy!

I have 1x11 on all of my bikes. For simplicity, I guess. Being able to go for a Z2 ride in the hills on the road bike would be possible with an extra 2 or 3 gears, but it’s something I can live without for now.

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The 10-36 cassette has pretty much the same jumps as Shimano’s 11-32 cassette and many more closely spaced gears than Shimano’s 11-34 cassette. Once you add the 13th cog, you get very similar gear ranges, too.

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You are exactly right. My next video I plan to discuss the gear ratios and how this set up eliminates any negatives of a 1x system when it comes to range and close gears compared to a 2x11 set up.

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You don’t get similar gear range really. I don’t know why you compared to 50x11-32 when I brought up GRX 2x11 (48/31 x 11-32 or 34), which gives ratios of 4.36 to 0.97 or 0.91.

The 1x13 setup with a 46T chainring you linked gives gear ratios of 4.6 to 1.28 (not sown was the 13th gear, which if you used a 42T would give 1.10 low gear). The top end of that setup is too fast to be used much (54 kph / 33.5 mph), plus doesn’t give you a 1:1 low gear which I find essential for MTB use. If you swap to a 42T chainring, you get ratios of 4.2 to 1.0, which is what I would run. The steps between gears are about the same, with GRX 2x11 having a slight edge.

The 1x13 would still be giving up a bit of range on both ends, have more friction (lost watts), and be a hacked together and expensive solution that would have extremely limited parts availability. It may or may not be lighter, depending on the cassette used.

With my 2x11 setup, I can and do link together road, gravel and XC MTB in one ride with one bike. And it’s a fully validated and supported, widely stocked system.

I think it’s neat that this exists. If you really want simplicity of 1x shifting or have a bike that doesn’t fit 2x with wide tires, this could be your best solution (though I question if Rotor or some other company didn’t have an off the shelf solution).

For me, I am really happy with GRX 2x11 for my all road bike. For MTB, I am 1x all the way, since I don’t need a huge gear range and instead value quickly making huge changes in gear ratio and it is great for full suspension bike design.

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The setup you give has a gear range of 450 %. Rotor makes a 10-46 cassette for its 13-speed drive train that has a slightly larger gear range (460 %). With your choice of chain rings, the most similar setup would be to use a 44-tooth chainring on the front. Note that the 10-46 cassette has the same number of gears 1 cog apart on the top-end as Shimano’s 11-32 cassette.

Rotor makes a 13-speed drivetrain. It costs roughly as much as Shimano’s and SRAM’s top-level electronic groupsets. So yes, parts are expensive, and are not stocked on the shelves of even well-sorted bike shops, I reckon. Nevertheless, it is an option, which is not hacked together and comes with a full list of options and features, from MTB to road, from oval chainrings to three different power meters and tri shifters to boot.

Evidently, people should use what they like. But 1x offers enough range and closely enough spaced gears to be a viable option for more and more riders. For example, IMHO a 48-tooth chainring is well too tall for most mere mortals, especially once you consider the people who are riding gravel.

My bike lost its front gearing thanks to Felt poor design.

Ive been thinking about getting a new bike, but if i can do something like this i would probably do it.

What would be the parts requirements to do this and the cost?

My bike is a shimano 10 speed bike.

This would be a great option for you then.

You can actually order the whole set up from Dirk Stock if you contact him. Not sure if you need Hydraulic or Mechanical braking but he can set you up with either. Contact him and he can help you with what you need but here is a list of what you would need.

Here is what you would need.

  1. Sram Shifters from Dirk. (He charged me 190 Euros for the modified guts so maybe a little more for the guts and brake levers)
  2. Sram 1x Rear derailleur (Long Cage: CX1, Rival1, Apex1) (anywhere from $50-$150)
  3. Sram XDR Driver (Sram’s freehub for their newer AXS stuff) (around $70)
  4. Sram Force AXS 12 speed 10-33 or 10-36 cassette (around $175)
  5. Fouriers Extender or other extender. (around $40)
  6. Sram AXS chain or other Sram/KMC 12 speed chain (yes you can use a non AXS chain on AXS cassettes) $30

So total would be around $600-750 for the set up depending on what derailleur you use. You could also bargain shop and find some parts for cheaper on ebay or other places if you wanted the price to be a bit lower.

I hope that helps.


Thanks for the break down. I will defenitly think about this. Myabe I should have mentioned that my bike is a TT bike. So not sure if i can do it with it…

Oh yeah that is interesting. Yeah I dont think he has done that modification yet but you can reach out to him. If there was enough room on a Sram TT shifter, he could probably do it but it is something he would have to work on.

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I will contact him…
It would be cool to try something like this…just for fun and giggles!

I was commenting on the 1x13 group shown in the video, not all available / possible 1x13. I even mentioned Rotor as having an off the shelf solution.

And I agree that people should run what they like. I just disagree with anyone saying that there’s no longer any disadvantage vs 2x11. There’s fewer disadvantages vs 1x11 or 1x12, but still a few remain, which I pointed out.

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I’m not sure who has made this claim in this thread — everything has tradeoffs. But I reckon that in a 5-10 years, 2x will be a rarity just like in the mountain biking world.

Many riders who don’t live near long, sustained climbs probably don’t use the small chain ring a lot. (I never touched my left shift lever last weekend when I rode along the coastline rather than venture into the mountains.) And once manufacturers (I’m looking at you, Shimano) dare to give riders more humane gearing options (I reckon most riders don’t need 50:11, even 40:11 or 42:11 would be plenty fast), there is less pressing need for superwide gear ratios on a road bike. The fastest gear I occasionally use on the flats is 50:12, I think, and then I am doing 50 km/h. (Of course, that only works when the wind is in my favor, which is as rare as you suspect it is.) Even for sprints I prefer 50:13.

It looks like Campy is coming out with 13 speed some time soon, with both close range and wide range cassettes. (9-36, 9-42, 10-46).