Creating this topic so we can nerd out about MTB drivetrains in typical Vital fashion.
I will start this off by discussing the latest one: SRAM Transmission Mechanical vs AXS and my thoughts and observations on it.
When SRAM first released their Transmission, there was a common misconception that you need electromechanical shifting (AXS) in order to get the perfect shift. People thought there is some sort of "chip" in the cassette that lets the AXS derailleur know when to shift safely. In reality, all the magic is in the cassette with the narrow wide profiles and predefined shift gates. In short, the cassette holds on to the chain until the correct shift gate arrives and then lets it off the cog. Based on my 2 year experience on Transmission AXS, SRAM appears to have measured the time it takes the chain to arrive at those shift gates in each gear at a predetermined cadence and baked that delay in the derailleur firmware. This is why even when a AXS Transmission derailleur is off the bike and you try to dump a bunch of gears, it slows down after the first few shifts.
Why are we after a "perfect" shift after over a century of this derailleur business? E-bikes! Suddenly every rider is exerting world cup athlete level power numbers through their drivetrains. SRAM and Shimano (Linkglide) are now taking a bit of control away from us to ensure we don't destroy these drivetrains under those circumstances. Eagle AXS (XX1) never had that delay due to the cassette not being as aggressively designed and that's because e-bikes were not common back then. When you go to shift, Eagle goes "sir! yes sir!" meanwhile Transmission goes "one moment please". The previous one wasn't too hot on e-bikes.
Now let's talk about their mechanical counterpart; SRAM 70/90. There were lots of discussions around how they would engineer that delay when there is no servo and firmware involved. There are scenarios where you don't necessarily need that baked in shifting delay especially with regular bikes. It could be that you are at a higher cadence and the shift gates are arriving earlier than expected causing the chain to shift as intended. This mechanical stuff lets us take full control and frankly it has been a breath of fresh air. Granted SRAM is trying suggest we shift slower by introducing a 1-shift shifter for e-bikes (warranty voided otherwise). Comparing my XX AXS vs 90 w/ all XX parts between two regular bikes, I prefer the full control of 90. Shifting quality is identical. I would like to see SRAM release a separate derailleur firmware for regular bikes and e-bikes. Remove the shift delay for us regular folks so we can enjoy faster shifting.
I've heard that the new unreleased Shimano Di2 does not have this sort of delay and it shifts much faster. Discuss away!
Does anyone have significant mileage on Microshift Advent X?
it’s light and cheap- curious how it works long term.
I've had the 9 speed on my franken-commuter bike for at least two years and it's been great. The only issue I had was one of the shift paddles started returning slowly and I had to open up the shifter and clean things out, which fixed it. Otherwise very little tinkering needed to keep shifting smoothly.
The shift paddles are a little different, you use your pointer finger to move down the cassette which took me a little getting used to. The shifting is maybe a little less smooth than the top sram/shimano stuff, but it's not bad and has a sturdy feel to it. Figured I'd try it on the commuter first, and while I would definitely run it on my mtb, I can't comment on how it handles chainslap/noise, which is important to me.
Everything SRAM does is targeted to mid to lower level riders. They sell more units on OE bikes than any other mfg 90 - 95% of OE builds are SRAM in MTB at this point. Their strategy is to reduce warranty and customer service issues with product and retain customers who spend money. If they wanted to sell an F1 Level pro system they would do it. But like F1, more people will drive an Accord vs a Race Car. Make products that are easily digestible by the mass mid west market and sell the most product and make the most money. Use cleaver marketing, team riders, ambassadors and whoever else to do it. Not sure why so many struggle to understand this concept? SRAM does not care about performance they care about profits and market share.
My Son has the Advent X 10 speed on his MTB and it has been pretty reliable. Shifting under load can be a bit loud but it does happens. It is definitely not Shimano's hyperglide+ level of smooth but it is pretty good. The clutch is ok and not as good as Shimano or SRAM's offerings. They use a ratcheting clutch as opposed to roller bearing type so there can be a bit of free play. As a result, sometimes you get more chain slap and sometimes less depending on where the rachet is sitting relative to the 4 pawls. It is adjustable however so you can always just tighten it down further. So far it has been good for local blue trails. The shifter is push-push, positive feedback, plasticky and and bit flexy.
Overall adequate but Shimano Deore or even a tiny bit more for SLX might be the better option overall.
Just checked my Strava - I have 823 miles on Advent X so far. Personally I love it, and I don't think it can be touched in terms of value
-Paid about $175 for the derailleur (v1 cage, supposedly v2 is a bit better), pro shifter, and alloy spider cassette
-10 speeds are extremely easy to set up and tune
-Less speeds means bigger ratio change between shifts, which I like
-Still shifts perfectly, have only ever used the barrel adjusters since initially setting it up
-Cage has been smashed against rocks with no issues
-Only issue: the plastic part of the clutch lock switch fell off, but the metal nub is still there so it can still be used
-Had to re-tighten the clutch a couple times
I highly recommend it to anyone doing their own build. It's a "budget" group but it performs extremely well.
both my boys had Advent 9-speed (not X) on riprock hardtails that they thrashed for 2 years with no regard for gentle or "proper" shifting technique, repetitive bike lay-downs on the driveside and no actual maintenance aside chain lube. one was on a 20" (no clutch) one was a 24" (clutch) and the cages were in the line of fire b/c of wheel size...the 20" cage practically dragged on the ground in low gear LOL. those drivetrains never flinched despite bent derailleur hangers and crappy alignment when i'd try to straighten the hanger.. very surprised at its durability.
I have about a year on my Advent X on my enduro bike and am a little frustrated. I find it very difficult if not impossible to get the indexing dialed in, and dirt seems to affect shifting performance more than other drivetrains i've run. That being said, I'm not using the Advent X derailleur and instead opted for the 11 speed Deore derailleur for the improved clutch which is apparently a popular upgrade.
However, I just purchased a gravel bike that also came with fully stock Advent X and the shifting is fantastic. There's a couple variables here- suspension vs rigid, different chains, different derailleurs, potentially different chainlines. I'm going to try running the Microshift derailleur on my enduro bike, as well as try a couple different chains. Can report back after some tinkering. Also curious to hear any tips other advent x owners might have.
I went with the microshift knowing that we were about to see a new crop of drivetrains released and didn't want to invest too heavily into one ecosystem. Currently waiting for long term reviews on the new cable actuated transmission and also hoping shimano released a lighter linkglide cassette (wishful thinking).
Fastest shift in the west is still the ol' trusty 11 Speed XT. Double gear downshift, crispy leaver feel, textured lever and can bend it pretty hard before it starts to shift poorly (unlike eagle or shimano 12 speed, which does good but could be better). I find that Transmission is a 180 stright into oncoming traffic in terms of progress, between the narrow-wide cassette, ridiculously massive derailleur, absurd price tag, and last but not least... probably one of the worse mtb inventions of the past 20 years, the UDH. Before the invention of UDH's, hangers were a lot smaller and flimsier, and would snap without much more extra force. Now, the fact that the UDH is massive when running a normal derailleur (non-transmission) and it's reverse threaded, if you ever get a stick stuck in your drivetrain and it somehow manages to get tangled enough in your drivetrian to push your RD in the forward direction, it will not only break everything (because the UDH will break last due to the fact that it is no longer the weakest link) but it you don't stop immediately, it will tighten into your frame further due to it being reverse threaded.
Dont ask me how I know because it's very emberrasing
Regarding narrow wide cassettes, when I first started seeing those I wondered how the hell they could keep the clocking right, after lots of high load and ill timed shifts. We see narrow wide derailleur pulleys that get out of sync with the chain, and those are in constant contact, unlike the cassette which is reliant on the chain always shifting at the intended gate between cogs. Has anyone had a chain get out of sync with the narrow wide teeth on their cassette?
Regarding Deore, Advent, XT 11sp, Cues/Linkglide, etc...does anyone have any suggestions for the lightest, strongest, setup for an e-bike? I have seen some e-bike guys talking about scaling down to 11 or 10spd systems, because they have the motor torque to help make up for the bigger jumps and smaller range of those systems vs. a 12 speed setup. E-bikes seem to really burn through drivetrains so I was starting to warm up to that idea of a less expensive but more durable setup, which still comes out fairly light due to the reduced number of cogs.
Wondering what’s so special in timing your shifting in order to do it fast and trouble-free! You just stop pushing as hard as you want for a second the moment you press the shifter, and voila - shift done without problem! Don’t need fancy electronic shifting for this!
It's even better when paired with an XTR shifter.
Talk me out of this
I’m currently on a mix setup that feels perfect to me
X01 shifter ( crisp feel, adjustable paddle )
Xx1 chain ( beautiful, no rush, lasts forever )
Gx shifter, cheap and honest other than the B assembly nothing major in terms of performance with a x01 or xx1
XT cassette ( the spacing is way better than the stupid 52/42 on Sram)
But here’s the thing, my previous GX was SILENT, no chainslap, strong clutch and all, but then the rivets gave up and it sounded like my grandmas wardrobe, so I got another one but it’s not like the previous one, the clutch is not that strong and it’s just noisy down the hill
I’m a sucker for CNC stuff and unique components, since i know about the ViVo Enduro I want one, I don’t really want to spend the money for it tho
But that thing is BEAUTIFUL, plus, it’s got an adjustable clutch
I've not tried the AXS Transmission yet but my eagle 90 is a little loud on some gears. It's smooth and it shifts flawlessly, but the "ticking" noise in the 6th and 7th gear is a little annoying. I'm not sure if that noise is ok or if something is wrong in my setup.
Otherwise the performance is great
Garbaruk cassette is your answer regarding steps between gears.
I'm sure some folks will break out their pitchforks, but I'll go on record and say that I much prefer my T-Type GX drivetrain to any of the last generation Shimano/Sram drivetrains. I found the 12s XT/XTR hyperglide offerings to be made of cheese, with constantly failing clutches, terrible cassettes that would either creak or just have their rivets fail, and the Eagle drivetrains seemed to either work well or not function no matter what you did.
I think the people who complain about the slow shifting of the wireless version should give it another try with the multi-shift on and set to all. I cannot tell you how nice it is to just hold down a button and keep on cranking hard and have it just not care, and that feature has alleviated the sensation of slow shifting in actual practice. But I do agree, if you're use to clicking through gears, that mental shift of just press and hold is a bit of a change.
Also, a bit of a personal rant: Shimano still using their micro-spline and various plates/spacers is one of the biggest reasons I'll not go back to shimano. They eat drivers and are a massive pain to deal with. Just use XD.
First thing I want to say is that I am a SRAM fan. I began running their drivetrains in the mid-00s and have ever since. At the time (and still according to many) Shimano shifted smoothly whereas SRAM was clunky. My point of view was that Shimano always felt vague and I preferred the noted clunk of SRAM as it went into gear. I still do. I have SRAM mechanical drivetrains on three bikes. Two have XO1 and one has GX all paired to 10-50t cassettes. I run Wolf Tooth oval rings with all of them. All have been trouble free through thousands of miles.
I have ridden many bikes with every level of Shimano drivetrains and more recently a few with Microshift Advent X set ups. They are fine, but I simply prefer the feel of the SRAM drivetrains. I have also ridden Transmission-equipped bikes and they too are fine, but they aren't solving any problems I have. I may eventually go Transmission mechanical. but again I am in no rush.
As for Axs and wireless drivetrains the absolute best use right now is on e-bikes as cable routing on most of them is nightmarish. A second and much smaller category for them would be on a travel bike where you can separate the frame. Again, one less cable to futz with. That said, I keep my phone and some wireless bone-conduction headphones with me on all rides. I have to charge those and just don't feeling like adding more to my charging responsibilities if I don't have to.
I remember XX AXS groupset making that ticking noise in those setup gears and required a click or two of micro adjusting. For mechanical, try playing around with the barrel adjuster to get the indexing just right. The gears will shift smoothly but as per SRAM's instructions, you need to adjust cable tension till the drivetrain is silent in all gears. In their official video they recommend doing that on the last two cogs but I needed to adjust it further up the cassette too. Also pay special attention to the chain tension in the setup gear as any slack there can also cause this.
Yeti factory racing ran the 11sp shimano XT for the old e-enduro series before it was paused.
Glad to hear shifting speed on the Sram 90 is respectable. Aside from my moral opposition to have batteries in my drivetrain, I found the shifting speed of T-Type GX to be fairly frustrating. I'll run my X01 setup until it dies, but I'd been worried about a future with few, if any, quality mechanical options.
Micro-spline was supposed to be Shimano's solution to the aluminum versions their older HG drivers getting eaten by cassettes. What's failing on Micro-spline?
How about some specifics? What cassettes on what hubs? I've run XT and XTR Microspline cassettes on Race Face Vault and Industry Nine Hydra hubs with nary an issue. Zero marring on any of them.
Same issue as HG with the scoring. I've had multiple XTR cassettes fail as well.
I was NOT a fanboi of the SRAM stuff through the 11 speed and early eagle stuff. Didn't like the feel of the shifting, etc. I just got a bike with the GX T-type AXS and I have been converted.
Meat powered taboot.
Thank you for your help! Might need to check the tension in the setup cog again.
I think the cable tension is quite high compared to the old eagle drivetrain.
You have to match the cassette and chain. You will not be happy running a Sram chain on a Shimano cassette unfortunately. I have run the Shimano chain/cassette with Sram shifter/RD and loved it.
Best value IMO is XT 12 spd. Clutch can be adjusted and shifting just works. Sram manages their product differentiation by tolerances in the RD. Just go into a shop and push the bottom of the RD cage back and forth on an XX1 vs lower level equipment and you will see what I mean. Shimano does something similar, but theirs is more about durability. XT will eventually get sloppy and XTR will essentially stay tight forever.
The problem is Shimano is that you can't see their product differentiation. Take chains for example, 99% of the differences are in the coatings. Difference in RD's is in pivot durability and forged vs cast parts. None of this is visible to the naked eye, but if you put a lot of mileage in on both systems you will know.
I moved to eagle 90 from X01. I went with the X0 cassette and after 2 rides I really started to enjoy the new drivetrain. Shifting under load is so nice, there is no need for faster shifting. This thing just works.
My little experience with transmission and Eagle 90 is that I far and away prefer the way eagle 90 shifts, but I have a gripe with how they keep the derailleur from going into the spokes with no limit screws, that being that the cage contacts the largest cog on the cassette. It's a little thing, but why design it that way over just building a limiter into the parallelogram? Doest even need to be adjustable, just keep it from touching the cassette. I would still take SHIMANO mechanical over eagle 90 if I was custom building a bike, but I wouldn't look to swap out eagle 90 immediately if it came on my bike.
I still prefer the XT after checking them
First for the price, Even if a lot heavier, but the spacing is closer on the biggest cogs which is what I’m after
No you don’t really HAVE to, the reasoning behind every components is in my first post, it shifts great under load, no better then when I had shimano everything else as well as the cassette,
Plus the derailleurs are made of cheese, they need everything to be perfect or they will perform horribly with random clicking and cracking sounds, while the gx just works and I don’t have to work on it every other week or every other month.
As I was saying I’m very happy with the sram chain on shimano cassette, even when everything else is shimano it’s still my choice as they outlast all options from shimano and works great.
And yeah while I haven’t ran XTR I know it lasts longer but still mile to mile it still requires lots more babysitting than eagle, my colleague is running it and the cable changing and clutch servicing is constant to keep it running good, else it’s just a mess
While me and the others running eagle have a drivetrain that just performs without so much babysitting for months and months, that’s why I keep running this setup
This is something more people should know
Always buy the XTR chain, never get anything else for a Shimano drivetrain. The XTR will last twice as long (if not more) and isn't twice the price so your actually saving money.
Zero Friction Cycling has incredible reviews that show the more expensive chains are well worth it for mileage
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