Mountain Bike Reviews Forum banner
Cancel
Create thread New Forums

"Downgrading" from 12 Speed to Advent X?

Jump to Latest
1 - 20 of 30 Posts

GuardianAngle

· Registered
Joined
·
51 Posts
Discussion starter · #1 ·
Thinking about "downgrading" from SLX 12 speed to Advent X. Has anyone else done this?

Some context:

My bike, a 2021 Specialized Epic Hardtail, came with a SLX 12 speed groupset. When it was new, it was incredible! Super smooth, huge range. But it has become finicky and annoying, for far longer than it was ever good.

Last year I kicked up a small branch that went into the derailleur, and since then it's been crap. Symptoms of a bent hanger (barrel adjuster adjusters only make it somewhat adequate on half of the cassette). However I have the Park hanger alignment tool and the hanger is totally fine, or at least close to perfect. So I think the derailleur itself is bent. At the time, SLX derailleurs were all out of stock everywhere I looked, so I just decided to live with it for a while.

It's extremely noisy (clicking, chain seems to grab bigger cogs) in the bigger gears, and when I'm in the 2nd smallest cog the chain likes to momentarily flop to the smaller cog. Lately shifting has gotten worse, and the chain occasionally falls off one of the jockey wheels, which is weird. I might need to service the clutch?

I do have close to 2000 miles on this drivetrain (I have swapped chains). So it's probably getting close to time to replace stuff anyway. The thing is, do I want to replace everything with SLX again and hope I can keep it good? At one point, I wanted to upgrade to XT or XTR to shed weight, but that is quite expensive, and I'm afraid I'd just have a super sensitive finicky drivetrain to mess with again.

So, lately I've been considering "downgrading" to Advent X. I can see a couple positives:
1: Lighter weight than XT, for less cost than SLX!
2: Less finicky drivetrain, arguably more reliable (allegedly).
3: Cheaper replacement parts and easier to find chains

I would lose out on:
1: Smoother shifting under load (allegedly)
2: Overall range (11-48 vs 10-51)
3: Smaller step increments between gears.
4: ISpec EV clamp compatibility

I would also need to change the freehub, but that is only $95 for my i9 1/1 hub and might be worth it for the long term.

I would go to a 34T chainring (up from 32T) which would get me closer to the top end speed, and be about the same as the 45T cog on the SLX for the low end. I rarely used the 51T anyway, but I would miss the 10T that I use fairly frequently. Maybe I'll look at a 36T chainring...

I have a drop bar gravel bike with Advent X and it's been pretty great, but I don't exactly ride that the same way and I also don't have that many miles on it yet to judge its long term performance.

Has anyone else done this? Do you have any regrets? Are you happy with the decision and would you do it again?
 
Discussion starter · #3 ·
I do have a new gravel bike with Advent X and I like it. It's one of the reasons I started considering this... But that kind of riding riding is completely different than MTB and the shifters are a tad different (brifters vs flat bar). I also only have around 250 miles on that bike, so I can't speak to reliability.

I'm really just looking for opinions from anyone that has made the switch. I see lots of praise for Advent X in general, but rarely see anyone actually going from a more expensive, fashionable drivetrain like XT to Advent X on the same bike. Or Advent X to XT/GX/etc.
 
#4 ·
I really like the performance of Advent X, generally speaking. At this point it would probably be my top pick for a “winch and plummet” type enduro bike, and it’s terrific on the fat bike. On more rolling terrain I find the huge jumps between gears a bit frustrating.
 
#6 ·
Sounds like you might just have a twisted derailleur or maladjusted B screw or both. I personally don't replace cassettes until they start skipping teeth.

But yeah man, it's all you, I'd personally take a fine tooth comb to that derailleur and see if it's twisted and confirm the jockey wheels are smooth & the B screw is dialed
 
  • Like
Reactions: MTBMILES
Save
Reply Quote Like Like
#7 ·
Advent X is good stuff, nothing wrong with it and a bunch of things right with it including performance, price and weight. Downside is the gear spacing, which can prove a little too wide at times. If you're good with that, no reason not to use it.
 
#9 ·
GuardianAngle said:
I do have a new gravel bike with Advent X and I like it. It's one of the reasons I started considering this... But that kind of riding riding is completely different than MTB and the shifters are a tad different (brifters vs flat bar). I also only have around 250 miles on that bike, so I can't speak to reliability.

I'm really just looking for opinions from anyone that has made the switch. I see lots of praise for Advent X in general, but rarely see anyone actually going from a more expensive, fashionable drivetrain like XT to Advent X on the same bike. Or Advent X to XT/GX/etc.
Click to expand...
Don't know if I'm of topic, but are the advent x dropbar shifters compatible with hydraulic disc brakes? Or do they only take mechanical disc brakes? I have an advent microshift 1x10 drivetrain, initially bought for replacing a 12 speed casette on a mtb, but now I want to use it to replace a 2x10 shimano tiagra (can't stand it) on a hybrid bike. Obviously I will need a new crankset, but I will only buy the advent Drop Bar Shift Levers if I don't have to pay an extra $$$ for new disc brakes.
 
#10 ·
SS777 said:
Don't know if I'm of topic, but are the advent x dropbar shifters compatible with hydraulic disc brakes? Or do they only take mechanical disc brakes? I have an advent microshift 1x10 drivetrain, initially bought for replacing a 12 speed casette on a mtb, but now I want to use it to replace a 2x10 shimano tiagra (can't stand it) on a hybrid bike. Obviously I will need a new crankset, but I will only buy the advent Drop Bar Shift Levers if I don't have to pay an extra $$$ for new disc brakes.
Click to expand...
The Advent X levers are a 15 year old design, they are mechanical only. The shift cables also run outside rather than under the bar tape. I had a pair of those levers a long time ago, they were decent back then but they are really bad compared to modern SRAM or Shimano both in function and comfort.
 
  • Like
Reactions: SS777
Save
Reply Quote Like Like
#12 ·
Why not Shimano 11 speed setup?
IMO it's still the most bomb proof setup. Small and short derr so it does not pick up all the trash, XT shifter that does not die like 12 speed, a ton of options for casettes, and it's cheap to run and maintain.
 
#13 ·
I've been extremely happy with my Advent X drivetrain and its taken some shots that have scarred the body and bent the hanger.

I've seen the same story as yours several times with Shimano 12s drivetrains. One hit that tweaks the derailleur hanger and the Shimano derailleur never shifts right again after realigning hanger. Nothing visibly wrong with the derailleur but it never functions smoothly again. Acts like a bent hanger but the hanger is straight.

The previous gen 11 speed shimano setups are my favorite. They seem to be more robust.
 
#14 ·
ljsmith said:
The Advent X levers are a 15 year old design, they are mechanical only. The shift cables also run outside rather than under the bar tape. I had a pair of those levers a long time ago, they were decent back then but they are really bad compared to modern SRAM or Shimano both in function and comfort.
Click to expand...
Thank you for the inside info, I think I will try it (I already have the advent cassette and derailleur) because I hate the fookin 2x10 tiagra (which my LBS installed without my consent:mad:). I'm assuming that I will need mechanical brake calipers only, right? (Cables are included when I order the dropbar levers?) Thank you again!
 
#15 ·
ToniT said:
Why not Shimano 11 speed setup?
IMO it's still the most bomb proof setup. Small and short derr so it does not pick up all the trash, XT shifter that does not die like 12 speed, a ton of options for casettes, and it's cheap to run and maintain.
Click to expand...
i'd be going from 2x10 with 24 small chainring.. 36 cog in the back... can i get that low gear in Shimano 11 speed 1X ?
 
#18 ·
RDs can and will be damaged. but instead of giving up all the 12-speed advantages, why not just get a Deore RD for $50 or so?

Since you have both types, YOU are the only one who knows if it is worth.

I have Shimano 12-speed bike and a 11-speed (KMC/SRAM) and the 12-speed shifting is 100 times nicer. if it wasn't for needing a new hub, I would spend whatever to get 12-speed, just for the nicer shifting. but this is just MY opinion. It is your money, and yo have both already, so no need to ask us.
 
  • Like
Reactions: Ktse and GuardianAngle
Save
Reply Quote Like Like
Discussion starter · #19 ·
As a last hurrah, I swapped on a brand new hanger and verified chain length, and the problems persisted. Maybe even got worse. I'm 99% positive it's a bent derailleur, and the annoying thing is Shimano 12 speed derailleurs come with a slightly bent cage from the factory, so there's absolutely no way of knowing how to bend it back to the correct position. I'm not sure if I'm more annoyed that the derailleur bent from a branch, or that the hanger didn't bend instead like it's supposed to.

I decided to pull the trigger [shifter] and give Advent X a try on my mountain bike. I'm keeping the SLX crank and just swapping to a Wolftooth chainring.

12 speed Deore derailleur is a good idea if I wanted to keep 12 speed on the cheap! It's not too much heavier than the SLX derailleur. I'm just nervous about the sensitivity of 12 speed again so I'm hoping Advent X is more robust and easier to adjust when needed. I do my best to do my own bike work, but I vastly prefer riding the bike to working on it... The less I have to fix stuff the better.

At the same time, I am sort of kind of weight weenie-ish. It is a carbon XC hardtail after all, so I do care a little about the grams. In the past the plan was to upgrade to XT or XTR over time with maybe a Garbaruk cassette...but Advent X is lower weight than XT for the price of just the XT cassette, with less fear of smashing expensive stuff.

I had a 32T chainring before. I'll go to 34T. That gets me close to the top end from before (3.09 ratio new vs 3.2 old). It works out to 0.85mph slower at a 90rpm cadence if I did my math right. It's not often I'm pedelling 24+mph unless it's a long downhill.

It's also really close to the 45T cog on SLX (0.708 new vs 0.711 old). So from a range perspective I'm essentially losing the 51T that I barely used before and a slight bit off the top.

That range is also spread across 10 gears instead of 11...so hopefully that won't be too annoying. On the upside, maybe I won't have to double/triple shift as much.

In a week or so when I get all the parts I'll install and see how this experiment goes! If it's a disaster and I ever want to go back to 12 speed shimano again, I still have the old stuff to put back on, albeit with almost 2000 miles on it...
 
1 - 20 of 30 Posts
About this Discussion
29 Replies
21 Participants
Last post:
Dictatorsaurus
Mountain Bike Reviews Forum
posts
16M
members
534K
Since
1990
A forum community dedicated to Mountain Bike owners and enthusiasts. Come join the discussion about bike parts, components, deals, performance, modifications, classifieds, trails, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
General Discussion Downhill - Freeride California - Norcal Shocks and Suspension Passion