Wide range MTB gearing (11-46, 11-48, 11-50 & 11-51) with 2x drivetrain for Gravel/Bikepacking/Road Bikes | Page 6 | Mountain Bike Reviews Forum (mtbr.com)

 

No derailleur can accommodate that much difference, even a 2 x with an 11-45 is limited.

A Pinion would work, 600% range.

 

Is that based on personal experience or a specific case you've seen? That transmission is neat but wouldn't that require a special frame? I probably don't need it to accommodate the full range, such as 22 to 10 because I can always upshift to the 38 when I want to go faster. I can make the chain long enough to accommodate the 38 to 51, and if the chain is too long, I can just avoid certain gears.

What I want is to be able to have a 38 up front for when I want to go faster and have a climbing gear low enough to satisfy me. I may have to just try it out to see what happens. I have a Sram 12-speed derailleur that can take a 52 and a long cage Shimano 12-speed derailleur that I can experiment with. I bought a 10-45 cassette for it but I have a 10-51 I can try first.

This guy is running something similar, and it looks like it works. 30/46 chainrings to a 11-51 cassette. The difference between 30 and 46 is the same as 22 and 38. This looks promising. I'll also be using 12-speed components, which may have more capacity.

Wide range MTB gearing (11-46, 11-48, 11-50 & 11-51)...

 

Look at how a 12s MTB rear derailleur works at each end of the gearing range, then try to add 16 teeth of chainring (and 8 complete links of chain).

With my 12s XO1 RD, in the 10 tooth, the lower pulley has gone backwards and upwards so far that the two jockey wheels are nearly level with each other. Now add 8" of chain to that. That won't work.

Also, in the link that you posted, the OP is NOT getting enough chain wrap on the cassette cogs at the high (10 or 11t) end of the range. You couldn't pay me to ride that bike.

 

I would be using 9 or 10-speed chainrings, which brings me to another question. Does it matter what chainrings I use up front?

The newer 12-speed Shimano drivetrains are not compatible with the older 9-, 10-, and 11-speed drivetrains. So if you want to use a 10-51T Shimano 12-speed cassette, you'll need a Shimano 12-speed chain and a Shimano 12-speed compatible chainring. But you can mix and match between all the Shimano 12-speed lines (XTR, XT, SLX, and Deore).

 

The newer 12-speed Shimano drivetrains are not compatible with the older 9-, 10-, and 11-speed drivetrains.

I run shimano 12 speed chain on 10 speed crank ( FC-m6000 ) without issues.

 

I'm going to invoke words not spoken in these parts since forever. Hide your kids, hide your wife.

How about a triple? Depending how adventurous you are - you can go towards bone stock 3x10 with 40/30/22 crank, or make an exotic 3x12 with the same crank, but 11-42 or even 10-44. That ought to give you a ton of range without trying to marry equipment that should never be mixed.

I run two bikes with 3x12 and... it just works.

 

Haha, I would at least toy with that idea in my head but no one makes a mid direct mount 3x front derailleur. But then if I really wanted to get adventurous, I could fabricate something to make a high direct mount fit....hmmm. No, but my issue isn't a limited high end but a low enough low end. It shouldn't be difficult to run a 38/22 up front. I just need to figure out how big of a rear cog I can run but who knows. Maybe I won't need it. I just received my Shimano 12-speed 36/26 XT crankset today, and I can't decide if I want to use that or my Raceface Turbine with a 38/22.

The other thing is, I thought I read somewhere that Shimano HYPERGLIDE+ chains (their current 12-speed chains) aren't compatible with narrow-wide chainrings. That's the only reason I went with a Shimano rear derailleur as I like Sram rear derailleurs because of that button that can hold the cage back for much easier wheel removal. Sram rear derailleurs have a narrow-wide jockey wheel. The reason I wanted to try their HYPERGLIDE+ chain was because they advertised better and quieter performance. I wonder how the HYPERGLIDE+ chain will perform on a 10-speed Raceface crankset. Or I could just run a Sram NX Eagle 12-speed chain. That's what I use on my other bikes.

I can either have a 100% Shimano system, setup as they designed it (36/26 & 10-45), or hack something together that may or may not work (38/22 & 10-51), lol. I feel like I should try the Shimano setup first to see if the low gear is low enough for me.

Which leads me to wonder if I should just go back to 1x with a 30T up front going to a 10-51. That will get me near what a 26 to 45 would offer, and I would only lose about 4 mph of top end (at a cadence of 80) not having the 36.

Actually, I could drop down to a 28T and pair it with a 52 in the back, and that will give me the same climbing ability as a 22 to 36 on a 26" bike. My top end will only be about 5.6 mph slower without the 36T second chainring. This 1x setup will almost match the range of a 3x setup of the past!

Oh, but I can't go xD because I have a Microspline hub, though 51 vs 52 probably isn't noticeable. Hmmm, maybe I should try my 2x idea afterall with the 10-51 and 36/26. This will allow me to experience the benefits of HYPERGLIDE+.

Analysis paralysis!

 

So, is the consensus that the most range one can get reliably out of a 2x set up on a road/gravel bike using conventional road brifters is something like 30/46 GRX up front and an 11/42 cassette and GRX (or possibly even an R8000) derailleur in the back (possibly including a road link)? I'm talking something that I could just slap onto a new gravel bike and just expect to work after a bit of tweaking. I really admire all these experiments at the outer limits, but want to know how far I have to back off before it gets easy enough that a less experienced bike tuner like me can just expect it to work.

 

46/30 with 11-40 is fairly vanilla. I've done that on 6 bikes now (both Di2 and mechanical) and my best friend runs it on his 3T. Some require a roadlink, my current bike does not. Not a ton of data points, but I've read of enough people doing it that I would call it "reliable". If you are used to 11-28 shifting then be prepared for things to slow down a bit. Just the nature of the larger jump between cogs. I think this is probably what you are looking for.

The 11-42 will probably require a roadlink (both of our current bikes do) and maybe a little fiddling, mostly with the B-Screw, but no mods like longer/different cages, larger pulleys. I have only set up 2 bikes this way, but have read anecdotal eveidence that it works well and requires minimal modifications. Just remember, one man's "works well" is another man's "nope, nope, nope". Ref the post above yours.

After that, you are in fairly uncharted territory.

 

Well, I am going to judge you for excluding 3rd party cassettes.
You are being judged.

Anyhow. It always boils down to how much jank you are willing to accept. Going off what a manufacturer specified usually entails some issues.

Microspline is a limitation because you have two cassette spreads to choose from, and each of these will dictate your RD choice and what you can do.

If you go with 10-51, then for good shifting you need 10-51 specific RD and those are completely incompatible with multiple chainrings. Large guide pulley offset is the culprit here.

If you go with 10-45, than, by Shimano's specification, you get 10T front ring spread to play with if you use dedicated RD.

if you use 10-45 RD on 10-51 cassette, not only that capacity gets reduced to extra 4T, but also your shifting is going to be somewhat compromised on the rear.

if you use 1X RD on 10-45 then the pulley offset would still exclude any front doubles.

Whence came my suggestion to use 10-45 + 2xRD and 32-22 crank + 2xFD. The only going off the manufacturer's specification would be size of the front rings, but that is pretty trivial to deal with. Otherwise, such drivetrain would be purely native.

I'm not saying that 38/22 crankset is impossible. I am saying that an FD that can shift 16T front difference is not of any of the current Shimano 2x offerings. You'd need a triple specific FD, and at that point getting a full triple makes more sense. FDs really, really like to shift what they were designed for.

had you gone with XDR driver, you'd have more wiggle room as there are also 10-30, 10-33, 10-36, 10-44, 10-50 and 10-52 cassettes, not counting 3rd party options.

If you went with HG, then what you want to achieve was trivially available with shimano XT 3x11 - 11-40 cassette and 40/30/22 crankset. Switch to 11-42 for that extra oomph would not hurt much and every part would be designed to work with every other part, no jank involved.

 

Haha, I am all for 3rd party but if they fail, I lose faith, which is exactly what happened when I tried one of those 11-52 cassettes off Amazon. It shifted great, until one of the middle cogs pulled out of a pin and got bent. This has never happened to any of my Shimano cassettes. I didn't have any issues with shifting though. I was putting a lot of power through it though, so I'm not totally against trying it again but now I have a Sram 11-50 on it, so unless that fails, I'm good.

If a 3rd party offered something I wanted, I'd be willing to try it, like maybe an even larger rear cog. Way back before Wolftooth came onto the scene with the 42T, I had a 41T by MTB Tools. This was back when 36 was the largest, so having a 41 on a 26" bike was crazy. Then when Wolftooth came out with the 42, I jumped on it and loved it, and then the 50T Oneup, which came with a really long cage to replace the stock cage on the Shimano derailleur. This stuff all worked great.

I guess my issue is with 3rd parties that use junk materials. I was curious about those 9-52T cassettes but the reviews don't look good.

The bike I'm working on now is my main all-purpose trail bike, so I don't want anything too weird going on. That's why I have all Shimano 12-speed components on it (except for the shifter because I like the way the Sram shifter feels more than the Shimano XT, the XT's action is not light enough). I wanted to see if any of Shimano's claims about Hyperglide + were true, which leads me to another problem.

I don't know if the Shimano chain I bought from a seller on Amazon is genuine. Who can I buy from that guarantee's authenticity? In the world of cameras, if I buy from B&H, I know I'm buying the real thing. Is there an equivalent in the cycling industry?

Does anyone make a mountain bike wheel with an XDR driver? And why would someone want any of those other cassettes on their mountain bike anyway? It's interesting that Shimano's 11-46 was for 1x while their new 10-45 is for 2x. Maybe their next 13-speed system will have a 10-50 2x.

But unfortunately for me, I don't think any 3rd parties are going to make a larger cog because there isn't as much of a need or demand. People seem happy with their 1x drivetrains, or so I assume. My biking buddies are still on 42s from the last decade. I guess I just need to exercise more.

One of the 11-speed mid direct mount Sram front derailleurs for my bike has 12T stamped into the cage, so I assume that means it handles 12T. I have all that parts I need for my experiments, so I'll just go try it out. The Raceface Cinch 2x spider came with 24/36 chainrings. I have a 38 I can pop in to try. If this works with the 10-51 out back, I will be very happy. In reality, I'd probably be perfectly fine with 24 to 45. Also, 24 is actually very close to what I would put in my 1x setup. I had a 26T Wolftooth chainring in front until I decided later that 28 would probably be better for more top end. If the Shimano 26/36 wasn't brand new, I'd try it first because I want to be able to return it if the Raceface setup works. The main reason I like the Shimano I bought was because I got it with 165mm crank arms, and I read that shorter crank arms might be better for your knees. I'm 5'9", and various crank calculators suggest shorter cranks than the 175mm I chose for my Raceface Turbine crankset.

There I go with my analysis paralysis again.

 

This is what works for me. Brilliantly. And has for a year or more. All on a non boost frame & 135mm spacing wheels. XT 11 speed shifter. m7000 SLX rear derailleur, & 11-46 cassette. Any non boost 2x crank, I'm running 36/24 steel chainrings (Shimano recommend only 10t difference, 12 works fine), and that's the max difference you can run. Chain has to be accurately sized to suit. And an XT side swing 2x11 front derailleur. On 36:11 (top gear) you get a 3.273 ratio. At 24:46 (low gear) you get 0.522 ratio. That's low enough to climb a cliff, even if you're old & weak. It works. As I said, brilliantly. Smooth, slick, noise free, & reliable. Bang for buck, I can't see how you'd do too much better.

Edit. Don't bother with that microspline garbage. A 10t sprocket is ridiculous. Absolutely ridiculous. 11t is bad enough, the inefficiency of 10t is crazy.

 

I'm back with an update, and I'm ecstatic to report that it all works! This makes me so happy!

The 10-51 tooth cassette works in a 2x setup!
The 22 tooth chainring works on the crankset in place of the 24 or 26.
The 38 tooth chainring works on the crankset in place of the 36.
Most importantly, the 38/22 combination works!
A 12-speed chain works on a 9 or 10-speed chainring.
A 12-speed chain works with 10-speed chainring spacing for 2x shifting.

I was about to try this 20 tooth chainring in the crankset but now that the 51 works, I won't need it.

https://amtber.com/ols/products/20t-chainring

I did try the 10-45 tooth cassette with a 22/36, and I found that the 22 to 45 combination was good but I wanted more 😄.

The 38 to 10 provides me with the same high gear as a 40 to 11, so it basically covers the same range as a 22/30/40 triple would on a bike with a cassette that has an 11 tooth cog.

I really like Shimano's Microspline system. I've considered a Sram cassette but they cost twice as much. I am using a Sram 12-speed shifter though because I like the way it feels vs. the Shimano XT 12-speed shifter I have on another bike. The main advantage of the XT shifter is that it can upshift two gears per pull while the Sram only changes one gear at a time. I can only imagine this would be an issue if I was racing. I hear people prefer the feel of Shimano's lower end shifters vs their XT shifter (12-speed). But the main reason I bring this up is so that people know Shimano and Sram 12-speed components are interchangeable (they have the same pull ratio).

Anyway, I'm proud to run this 2x setup while almost everyone else has seemingly switched over to 1x.

Here's a picture of the large-large combination. I would never use this but it's good to know it won't break anything if I accidentally shift into it.

Here's the small-small combination to show that the RD-M8120 derailleur has enough capacity to pick up the slack so that the chain at the bottom doesn't come into contact with itself on the upper jockey wheel. Right now, the chain does not touch the front derailleur cage, but if I were to try the 20T chainring, it would probably touch in this combination, but I would never actually use the small-small combination, so this would be ok.

 

You forgot to compress the suspension for the big-big combo. If you do, you will snap the derailleur.
EDIT: Also - 57T capacity. That is... brave.

 

Well, I thought about suspension compression but then I figured I would try to stay out of the big-big combination, and there was still a little slack left, so I wasn't immediately concerned, but since you brought it up, I decided to check, so I deflated the rear shock and found that it allowed about 2-3 inches of travel (out of 6 inches), so I added 3 more links back to the chain plus a quick link but found that it was too much, so I removed 2 more links from the chain, which I think is 2 links added in total. But because the chain is longer, I had to turn the B-screw all the way in, but it seems to work ok now but I might try the link extender to see if it will improve the shifting.

I'm glad you brought this up because now I don't have to worry about anything breaking at all, and I can use the big-big combination now. Yes, you're right that there is a little harmless extra slack in the small-small combination, which I will try to avoid. I'll try to only use the small front chainring when I use the largest rear cogs, and maybe I'll just keep it in the 38 most of the time.

The alternative solution to this (instead of making the chain 2 links longer) is to use a 36 instead of a 38 tooth chainring in the crankset. That's actually probably the best setup for this bike, and it doesn't require any add-ons like the link extender, and in the small-small combination, the chain doesn't sag.

Here's what it looks like in full compression with the 38 going to the 51. There is still a tiny bit of slack, so the derailleur should be safe.

Also. Since you have already made this thing and I am an experienced drivetrain range exceeder.

If you set up this drivetrain as if it was 1x12 with 38T as the driver ring, then it ought to be able to use largest 5 or so cogs of the cassette on the small ring. Some B-distanced fiddling might be necessary for this to work. If you were to do it, than you'd get 'regular' 1x12 on the 38 with all gears available to use and "bailout" low gears to climb just about anything.

Yes - in this setup the chain will sag on the small-small combos, but its better to have a sagging chain than torn off derailleur.

 

Also. Since you have already made this thing and I am an experienced drivetrain range exceeder.

If you set up this drivetrain as if it was 1x12 with 38T as the driver ring, then it ought to be able to use largest 5 or so cogs of the cassette on the small ring. Some B-distanced fiddling might be necessary for this to work. If you were to do it, than you'd get 'regular' 1x12 on the 38 with all gears available to use and "bailout" low gears to climb just about anything.

Yes - in this setup the chain will sag on the small-small combos, but its better to have a sagging chain than torn off derailleur.

 

I just added a Wolf Tooth Components Road Link to move the rear derailleur down just a little. I chose the Road Link because it's the smallest one I could find, and it has an offset to mount the derailleur in the same plane as the original mounting point. The shift to the largest rear cog is smoother, however shifts to the smaller cogs seem slower due to the increased distance between the derailleur and the cogs. I wonder if I should go back to a 36 in the front instead of the 38. If I do that, I won't have to use the link extender, so the shifting will be back to Shimano's standards. The chain will also not sag in the small-small combination because I can remove the 2 links I added. But everything works right now, so I'll try it out this weekend at the bike part to see how it performs.

 

Looking at your pictures I think I’d remove the Wolftooth road link and use a longer chain length, so that the 38 tooth with 10-51 cassette is fully usable throughout its range.

One test to do as well is to put it on the 38 x 51 tooth combination, and then spin the cranks backwards repeatedly to see if the chain will fall off when back pedalling. The double chainring will affect the chainline, as the chainring won’t be in quite the same place as a dedicated 1x crankset chainring, so it’s worth checking to avoid any surprises mid ride.

For the small inner chainring having a sagging overly long chain on those smallest rear sprockets (in order for the chain length to run acceptably on the 38x51) would be ok to have. It’s not a combination you’ll use, and also when you sit on the bike with the suspension compressed a bit that will pull the chain tighter when riding so it won’t be as slack in use.

 

Actually, right now, the 38 can use the entire range of the 10-51. It's the 22 that I need help with because the chain ends up being too long after I size it for the 38. This shifting noise occurred after I added 2 links to the chain to prevent full compression of the suspension from tearing the derailleur off. Basically, what's going on is when the chain is shorter, it pulls on the derailleur cage more, causing the upper jockey wheel to rotate farther away from the cogs. When I lengthened the chain, the cage was no longer being pulled as much, so the upper jockey wheel would push the chain against the 51T until it engaged, and after it shifted it was fine but I just didn't feel comfortable with that sound because it was unusual but who knows, maybe it's ok for it to make that sound. The chain still shifted into the gear just fine.

Here's a picture showing how close the upper jockey wheel is to the 51T before the shift. The chain is on the 45 in this photo. In this current configuration, it makes no unusual noises during the shift, whereas before, I would hear a slight rubbing sound before the shift, but after the shift completed, the chain would pull the cage, moving the upper jockey wheel away.

Looking at your pictures I think I’d remove the Wolftooth road link and use a longer chain length, so that the 38 tooth with 10-51 cassette is fully usable throughout its range.

One test to do as well is to put it on the 38 x 51 tooth combination, and then spin the cranks backwards repeatedly to see if the chain will fall off when back pedalling. The double chainring will affect the chainline, as the chainring won’t be in quite the same place as a dedicated 1x crankset chainring, so it’s worth checking to avoid any surprises mid ride.

For the small inner chainring having a sagging overly long chain on those smallest rear sprockets (in order for the chain length to run acceptably on the 38x51) would be ok to have. It’s not a combination you’ll use, and also when you sit on the bike with the suspension compressed a bit that will pull the chain tighter when riding so it won’t be as slack in use.

 

On my last 2x drivetrain bike I had 38/ 26 tooth front chainrings with a 10-42 11 speed cassette.

For the front shifting on that setup I was always careful to change down from the outer 38 tooth ring to the inner 26 tooth ring when I was still 3 sprockets away from the largest rear sprocket. I’d stay in the 38x42 if I was sure I could make the hill in that gear but otherwise I’d get my front shifting done well in advance so I was never caught out trying to do a front down shift mid climb.

Trying to shift between the 38 and 26 tooth chainrings under load with maximum chain tension and chain angle was the most likely thing to drop the chain on that bike. The straighter the rear chainline was before doing a front shift the less likely the chain was to drop.

On your bike you have a greater jump in gear range again so might need to do the same when riding to keep the chain on as well.

 

Do you really need that 22-51? You might get away with 38-28 or 38-26 and save yourself some headache.
I already told you - jank will be happening.

 

Ha ha ha. I thought I was a bit soft running 28:51, or 24:46. It appears not 😂

 

How about replacing the stock B tension screw of the rear derailleur with a longer length screw from a hardware store? That will give you a greater range of adjustment.

 

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extra gearing is useful,, but the kickstand super useful!

 

I was so intrigued by this thread, that I made my own version of this, using my copious amounts of chinesium. Mounted to my commuter.

11-50 cassette, 44-34 rings. Total capacity of 49T.
The rear mech is absolutely maxed. I have 12 gears on the 44 ring and 8 on the 34 ring. Total gearing range is 588%. Equivalent of 3x10 with 22-32-44 crank and 11-32 cassette. If I went for 11-36, I get 650%

Now - rings here are pretty large, thus the spread is pretty small. If one went for 32-22 crank, then with 11-50 I'd get 661% of range and that 22/50 oomph gear.

Shifting is fine, not great, but acceptable.

 

I am just seeing this thread. I have got the Idee and many helpful advice from @jrob300 and built a road bike with (impossible as a mechanic said) setup.
Kouta Kougar Frame (yet rim brake)
Di2 GRX RD-815, Garbaruk 11-15 11sp
The cage is the original but the upper and bottom pulleys have been changed
Di2 GRX FD , SRAM XX0 42/28 Crankset (formerly I had FSA 46/30)
RoadlinkDM + Roadlink
It works already very well.

So "extrem" configuration are possible but it was not easy and took some time till everything is worked

 

Nice...not knocking 1x12 systems as I have one on my Intense Primer but never experienced a 2x10 set up except recently on a couple early mid 2000 retro hardtail builds. They shift fine and effortlessly and are a nice upgrade for the bikes mentioned. They also have a nice gear spread. Really would like to try something like yours and see how it works out on the trails I ride my Intense on. Went from a 3x9 26er to my current 1x12 system...