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XC iconoclast
Church of Real Metal
2,198 Posts
Discussion Starter · #1 ·
It was Plato that first said necessity is the mother of invention, but the country where Confucius was from sure picked it up fast when it comes to cheaper mountain bike stuff:
BOLANY 8-9-10-11-12 Speed Cassette 11-32T 11-36T 11-40T 11-42T 11-46T 11-50T 11-52T Wide Ratio MTB Bicycle Part Freewheel Sprocket with Rear Derailleur Extension $49.88 (all cassettes)

I've been agonizing about what my next drivetrain will be. Have not tried 1x yet. I like climbing, and the combination of steep climbs (sometimes 20%+ grade hardpacked) and relatively long, straight fire roads to/from the trailhead make 1x tough for my situation. Bottom line, I need range more than great shifting.

I already have a 9-speed 22/36t crankset with removable chainrings. Dropping the chain every 2-3 downhill segments, obviously annoying...thought of the Microshift clutch derailleur, cassette, and shifter, but then I saw this 11-50t cassette on Amazon.

9-speed 11-50t is great, but it's not quite enough for me lol. And I mean like if it was only 4-5% more, like 11-52t, I think it would be enough, because I will not go below a 32t chainring with 1x (only if I did an XD driver and went below 11t for the cassette). And I want 0.62 or less granny ratio (currently have 0.55 with 22/40t and I love it on steep stuff). 11-52t with 32t front would give 0.61 granny, acceptable. 11-50t with 32t front would give 0.64 granny, OK for most climbs but not all.

So what I'm thinking is, if its possible, to:
1. Get rid of the front derailleur
2. Keep the double chainring crankset, but, again if this is OK to do, put a narrow-wide 28t chainring on the smaller (left) side, this would give a granny ratio of 0.56. KEEP the 36t ramped chainring on the right side. I then mountain bike up and down hills on the 28t narrow-wide ring, then manually switch the chain to 36t on relatively straight hardpack or pavement back to the car or home.
3. I already have the extender installed, just install the 11-50t cassette and hope it can get to 50t. Right know I have the Alivio M4000 SGS long cage RD; do you think something like a 9-speed XTR long cage would clear 50t better, or would it be about the same? If not, what can I do?

I've read online that some people drill a hole in a 10-speed SGS RD about 1/3 of the way from the cable inlet to the other side of the top of the RD and then thread the cable through there instead of the normal inlet, then wrap around the cable at the bottom around the tightening screw as usual. That will change the pull ratio back to the 7-9 speed 2:1, but the hole has to be in a pretty exact place, I dunno if I'm up to trying that or not. This is for getting a 10-speed clutch RD on a 7-9 speed drivetrain, but if I already have a narrow-wide chainring up front do I even need a clutch in back? The microshift 9-speed RD as mentioned above has a clutch and is rated for 11-42 w/o an extender, but I'm afraid that it may not be compatible with this off-brand cassette.

Plan B: Go 11-speed 11-52t.

As far as pricing is concerned for 2x9 vs. 1x11 or 1x12:
2x9 --- crankset & bb $90, cassette $50, shifter $30, chain $15, RD generally $40-80. Total cost $225-265. Not much cheaper than 1x11 but it really depends on what you are starting with (as in if you started with 3x9 or not --- I started with 3x8). Since I've already installed the 9-speed crankset and RD, then shifter $30, cassette $50, chain $15 = only $95 more to do this. Range is an awesome 5.8.
1x11 groupset around $350 w/crankset, highest range is 4.7 (11-52t)
1x12 GX groupset around $500 w/crankset, highest range is 5.0 (10-50t, or 9-46t)

That's plan A. Plan B would be get rid of the front derailleur, get rid of the outside 36t chainring, put on a 32t narrow-wide chainring, and then do an 11-speed conversion: shifter $50, the Bolany 11-52t cassette $50, chainring around $30, chain $30, RD (XT RD-M8000) around $85. Total cost $245.

$245 for a real 1x11 setup with just enough range vs. $95 for plenty of range but having to manually switch the chain at the bottom of the hill. The rebel in me says do the 2x9 and screw 1x11.

1,245 Posts
I think, and excuse me if its just my thinking, that you are overthinking this.

1. Can your crank accept a bashguard? If yes, get one. Bam - 95% of chain drops are gone.

2. If your crank can't accept a bashguard, get a blackspire stringer chain device. Bam 99% of chain drops gone.

3. Get a rear mech with as short of a cage as possible. The longer the cage - the less chain tension there is on the drivetrain. Clutchless SGS derailleurs are meant for trekking bikes.

4. You _can_ use 10/11/12 speed shimano mtn rear mech on a 8/9 speed drivetrain by using 8/9 speed SRAM ESP shifter ( their old stuff ).

In my opinion though - what is the issue you are trying to fix? You _need_ a clutch for those massive chinese cassettes to work reliably. Otherwise cassette backlash will eat you up ->

If you want to retain the 2x9 - do it the 2x9 way - bashguard+chain device+short cage mech.

If you want to go 1xX - on the cheap it is to get SLX 7100 rear mech, 10 speed shimano dyna sys shifter, chain, 10 speed chinese cassette and N/W ring.

But for not much more you can go full 11 or 12 speed because its not much more expensive then 10 speed.

Shimano 10/11/12 speed MTN stuff is completely cross compatible ->
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