natch

Just got a Used 2012 Tallboy LT that was converted to a 1 by drivetrain. It has a nice Shimano XT M786 Shadow+ 10 Speed Rear Mech with a Shimano CS-HG81-10 10 cog 11-36T cassette that looks to be in good shape as well as a 10 speed Simano XT Dynasys right shifter. And a SRAM PC1091 chain that is just about due for replacement (almost at .75 wear). In front it has an Deore XT dual chain ring crank with a Raceface 30T D40278 chainring on the bigger ring mounts of the crank.
Problem: This is not giving me a wide enough gearing range. The Granny gear combo of 30x36 is not easy enough for me. And the max downhill gearing of 30x11 is not enough for even small downhills.
Solution 1: Bike shop wants to go GX Eagle to the tune of around $500.00.
Solution 2: Get a Shimano XT M786 Top Pull 2x10 Front Mech ($30), a set of Shimano chainrings 38T & 26T ($35), a new KMC X10SL 10 Speed 116 Links Chain ($25), Shimano shifter cable and housing ($19). And a compatible 2x shifter and possibly a new cassette with an 11x40T range, if I find I want more granny gear.
The second solution seems much more cost effective and I should be able to do it myself. But I am having a hard time figuring out what shifter to use. Prices vary tremendously and it is unclear what really works, particularly when so many offerings are 2x / 3x capable.
Anybody have some advice on what shifter to get? I'm thinking, a high end shifter is overkill for a front derailleur so I want to go as cheap as I can without sacrificing durability.

HerrKaLeun

Look at gear calculator what range you actually want and need.
You should be able to go Eagle with less. i assume they included a new crank in their estimate. You can reuse your crank if you find a suitable chainring. actually your current chainring should work. You basically need 12-speed shifter, RD, and 12-speed chain. I'm too lazy to google, but should be $300+
but if you need a new hub to use xD driver, this will cost you... to stay with your hyperglide freehub, you also could go 1x11 for about $150

Since your chain is worn, who knows what condition your cassette is in, so you may need a new one either way. they cost about $30 for 10-speed, unless you want wide range.

Gallo

I like the 2x myself

cpach

The 2x option makes reasonable sense. Shimano has not changed front shifter ratios for mountain drivetrains so use whatever.

Minimum cost on an eagle setup is about around $440 at retail in parts. $125 derailleur, $45 shifter $33 chain, GX eagle. About $60 for a new wolf tooth chainring in a 34 or 36t depending on how high a gear you need. About $150 for a Sunrace 12 speed 11-50 cassette (available on QBP, any shop should be able to get this) which will work on your existing freehub. Whatever cost of of cables, housing, and labor.

Darth Lefty 

Sunrace 11-40

natch

1. SunRace CSMS3 11-40 < $29
2. 104mm/38T ramps and pins for 38.24t Shimano SLX FCM675 10 Speed Double Chainring < $26
3. 64mm/24T Shimano Deore FCM590 10 Speed Triple Chainring < $6
4. SHIMANO DEORE XT FD-M786 2 x 10s Bike Front Derailleur Clamp Mount 34.9mm NEW < $19
5. NEW Shimano XT SL-M8000 Front / Left 2X 3X Trigger Shifter < $19
6. MRP S4 Bashgaurd 104x36-40T Black < $26
7. KMC X10.93 , Nickel Plated 116 Link 10 Speed Chain < $20
8. Laying around: Shifter housing, Ferrules, cable end cap < $10
9. My labor. Hopefully will not end up in the bike shop after I work on it. Thank You, YouTube.
All told, it is less than $150.00 in parts. About $300 less than a Eagle setup with a Sunrace cassette.
The tough decisions that needed more info:
1. Any Shimano MTB front mech shifter will do as they all pull the same amount of cable.
2. Definitely use the 10 speed rings so the match the 10 speed chain.
3. Definitely use a bash guard to fill the space of the biggest ring AND to be, you know, a bash guard.
4. Could have lived with the existing 11-36 cassette as it appears to be in pretty good shape. But my knees are thanking me in advance.
I will report back on how it all worked out.
I am also debating about replacing my BB. I'll give a look and feel once I get in there to see if it seems to rotate smoothly or not.
I am also considering pulling and greasing my VPP pivots. I was planning on waiting to the end of the season. But maybe that is taking a big risk. Not sure.

dminor 

Too bad you didn't just work out the 1x setup; you'd have been farther ahead for less money. You could have gotten a range-expander 42T cog (like a WolfTooth or other) that would have come with the extra mid-range cog and the longer B-limit screw and you would have been done - - and not have to mess with front derailleur/shifter/2nd ring, etc.

natch

Bike shop insists I'd need a new rear derailleur ($60) with a 42t cassette (cheapest Wolftooth cog ($49). That gives me the granny gear I need, but not the high speed/downhill gears. A 2x setup means a much broader range. As I frequently bike in Center City (downtown) Philadelphia, I need that speed that the big ring will give me to quickly get out of the way of cars trucks and to pop thru those intersections when needed. Weight isn't an issue, as I can (should) lose way more weight than what the front bits are costing me. And in a big city, a BIG rear cassette just screams "$$$ - Steal me!" I've been riding dual mechs for as long as I can remember. Clearly, 1x is the long term solution, but that might be on a new bike or 3 to 5 years when 1x with a monster cassette is commonplace and cheaper.

But Thank You for your feedback.

dminor 

If you have a long-cage or even a medium-cage derailleur, you have enough chain wrap capacity. A short cage won't quite cut it but I doubt very highly that's what you have. It sounds to me like the shop is BSing you to sell you more stuff than you need.

BTW, for the record, my first range-extender cog was an alloy Chinese Wolf-Tooth knock-off that was not worth the (considerably less than WT) money I spent on it. But it was still a good cheapskate investment to find out that 42T was what I wanted. The next time around, rather than spend the money on the Sunrace I cheaped oout again (haha) and bought a Chinese ZTTO 11-42 cassette. A touch heavier by a few grams but has a better gear-spacing than the Sunrace, IMO - - AND has a steel big cog. It has held up admirably for almost a full season now and only set me back $35 off Amazon.

natch

Thanks for the feedback dminor. It is a medium cage. already got everything but the SunRace Cassette (which is also steel, around the same price as the ZTTO 11-40) and the rings, all expected in this week. Think I'll give it a go with what I bought and see how it all works. In retrospect, an 11-42t cassette with a 32t ring would have extended both high and low ends a little. It might have been enough. Still think my current plan is OK and when it all wears out, it will be time to UG to the new most durable smooth shifting 1 x 12 system that will be available at that future time.