Mountain Bike Reviews Forum banner
1 - 20 of 26 Posts

Geargut

· Registered
Joined
·
4 Posts
Discussion starter · #1 ·
Hi all. I've got an old specialized XC expert. It's been my bike for many years and that's not going to change. I've decided I want to upgrade the 3x9 drivetrain to a 1x12 setup. I've seen a lot of good videos that talk about how you will get basically the same kind of gear range with the 1x12 setup that you'd typically expect from the 2x9 (minus to biggest front crank ring of course - I never use it anyway). The issue is that most of these videos are featuring bikes that have 29 wheels. I'm just wondering if I would encounter any drastic problems by converting a 26 to a 1x12. Thoughts appreciated.
 
You should be fine, just make sure you get a cassette that fits a normal freehub and not a microspline, XD driver, or other proprietary interface unless your rear hub can switch to the appropriate one at the same time.

Cassette options should be SRAM NX Eagle, Garbaruk, and Sunrace, there may be other options though.

If you're doing a new crankset and not just swapping out a middle ring, same thing, just make sure you match up the crankset/BB with your bike which I'm guessing is a normal 68/73mm BSA, but you'll find cranks in just about every BB combo out there.
 
Go to Sheldon Brown's gear calculating web page. Input your current gearing into the calculator to look at your current gearing in gear inches or gain ratios. Then put in your possible new gearing in to get a feel of what the new gearing range you will have. You don't need quite as low gearing on a 26er as you do a 29er. For example, a 32/51 combo on a 29er is roughly equivalent in gear inches to a 32/45 combo on a 26er.

When I chose my new gearing I knew I never used my 22/34 gear combination on my 26er as it was way too low (16.8 gear inches) for me and was useless. Lowest I ever used was 22/30 which was around 19 gear inches on a 26er. When setting up my new gearing I shot for a ~18-19 gear inches and it worked out great without wasting a low gear I would never use. Same thing when I set up the gearing on my 29er. I knew I liked ~18-19 gear inches and for me to get that on my 29'er I used a 30/46 for my low gear which worked out perfect for me.
 
It'll work. You'll love it!!

Your big question is whether to choose SRAM or Shimano. Cheap SRAM mechs and shifters and chains aren't as good as good as inexpensive Shimano stuff. Peeps LOVE their expensive SRAM stuff though.

Jestep mentioned the cassette options, they'll fit your current rear wheel. I'm using the Sunrace 903 with Shimano bits...and it just works.

You'll need a chainline of ~48mm (measure from the centreline of the BB to the middle of the teeth of the single ring. Any lower than that e.g. 45mm and the chain will rub on the e.g. 13t when you're in the 11t of the cassette. If you use a chainline of e.g. 52mm, the chain will be on a horrendous angle when you're in the easy gears (though the Shimano chainline is 52mm for your hub spacing.

You can modify your chainline if needed. It's easy if you use a bolt-on chainring. Be careful if you want a direct mount chainring on Shimano 12 speed cranks, only Garbaruk make a ring that sits at ~48/49mm. SRAM direct mount has plenty of options for 49mm

1 x 12 is VERY senstive to set-up. So, you'll need to factor in the cost of a derailleur hanger alignment tool. Also, you'll get best results from good quality cable housing (Shimano SP41 is the way to go). You'll also want to follow the installation instruction to the letter...to the letter. Installation / set-up of 1x12 from both Shimano and SRAM is different from eath other and older bits. It's not difficult, one just needs to be precise :)

There's a LOT of threads here on MTBR about all of this. Let us know what you're thinking and we can point you in the right direction...
...and here's a great way to search MTBR yourself (it's search engine sucks). Search for "sunrance 903" via typing the following into google
site:forums.mtbr.com sunrance 903
 
Interested in hearing how this goes.

With regards to potential problems, depending on which brand/option you choose, the cassette may be slightly dished towards the spokes. There may be a very small chance that the cassette or rear mech fouls the spokes on a 26" wheel.

This thread might help a bit --> Do any of you run 1x11 or 1x12 on your 26er?

Have you considered the Deore 11-51 option which is 11 speed? Its almost the same range as 12 speed 10-51. You can keep your old hub and probably your old crank as well
 
Hi Dave, the cassettes listed use the old HG standard, and there are heaps of 12 speed chainrings that mount to "old" - non direct-mount cranks.

Have you considered the Deore 11-51 option which is 11 speed? Its almost the same range as 12 speed 10-51. You can keep your old hub and probably your old crank as well
 
With regards to potential problems, depending on which brand/option you choose, the cassette may be slightly dished towards the spokes. There may be a very small chance that the cassette or rear mech fouls the spokes on a 26" wheel.
I'm not sure what you mean by this Dave. The spokes on a 26" bike move away from the hub at a larger angle than on a 29 or 650b wheel. For a given hub spacing (135mm in this case) the offset / dish is the same matter what the wheel size. On a 26" wheel there's a shorter distance over which to triangulate the dish, hence the angle will be larger, hence less chance of a cassette or mech hitting the spokes.

As per the thread you linked, howerver, the mech will sit that much lower to the ground on a 26er...if it's an issue, use a budget mech :)
 
Think I'm gonna go with SRAM Eagle kit. I was just concerned about making sure I get as close to the 2X9 gear ratios with the 1x12 with a 26er.
This is a good web page to to help you choose cassettes and front chainring --> https://gear-calculator.com/
Assuming you have a 2x9 with 22-36 front rings and 11-32 cassette, it looks like you would have almost identical gear spread with a 34t and NX 11-50 cassette


1911493
 
Discussion starter · #11 ·
This is a good web page to to help you choose cassettes and front chainring --> https://gear-calculator.com/
Assuming you have a 2x9 with 22-36 front rings and 11-32 cassette, it looks like you would have almost identical gear spread with a 34t and NX 11-50 cassette


View attachment 1911493
Yup, that's what I need. Think I'm gonna order this https://www.amazon.com/SRAM-Eagle-G...D/ref=sr_1_10?dchild=1&keywords=sram+eagle+dx&qid=1610594292&sr=8-10&th=1&psc=1

I'm more of an XC rider so I don't really care if the derailer is closer to the ground. I'm not doing any hard core stuff anyway.
 
Derailleur close to ground is no issue. Your wheel is there.

if you want it, do it. You’ll love it.

11sp 11-51 - 34 oval here. Same old cranks. 26 inch wheels. 51 tooth chainring looks like a wagon wheel on the bike. Rides GREAT.
 
I'm in the process of converting a 2004 Fuji 26er right now. From 3x8 speed 22-32-42 with 11-30 cassette, to a 1x11 Box Two, 11-50t cassette with a 36t oval chainring. Also using old cranks (for now). The new drivetrain is on, but I have not ridden it yet because I'm also converting to a rigid fork, and disc brakes, and don't have that sorted yet. It's going to be quite a different bike. Shifts great on the work stand. Derailleur does look awfully low to the ground, but this will be for rail trails so I'm not concerned.

I don't have any advice that hasn't already been said. But wanted to just add this to say you should go for it. Also +1 to the gear calculator on Sheldon Brown's site.
 
Yup, that's what I need. Think I'm gonna order this https://www.amazon.com/SRAM-Eagle-Groupset-Black-175mm/dp/B07DVP5FWD/ref=sr_1_10?dchild=1&keywords=sram+eagle+dx&qid=1610594292&sr=8-10&th=1&psc=1

I'm more of an XC rider so I don't really care if the derailer is closer to the ground. I'm not doing any hard core stuff anyway.
My heart bleeds for you having chosen SRAM over Deore (Pinkbike award winner x2 in 2020). If you really want the SRAM, make sure that the chainring has 6mm offset to give you 49mm chainline. 3mm offset will give you 52mm chainline.

Why do you want the SRAM?
 
Discussion starter · #15 ·
My heart bleeds for you having chosen SRAM over Deore (Pinkbike award winner x2 in 2020). If you really want the SRAM, make sure that the chainring has 6mm offset to give you 49mm chainline. 3mm offset will give you 52mm chainline.

Why do you want the SRAM?
I'm not pounding on it. I'm a pretty casual rider comparatively. The SRAM Eagle NX looks like it's most compatible, straight forward installation and adequate quality for the kind of riding I do. Gear ratios also closely match my 3x9.

 
My heart bleeds for you having chosen SRAM over Deore (Pinkbike award winner x2 in 2020). If you really want the SRAM, make sure that the chainring has 6mm offset to give you 49mm chainline. 3mm offset will give you 52mm chainline.

Why do you want the SRAM?
If 12sp Deore is anything like XT or XTR with their design flaws in the shifters, and horribly slow warranty service right now, it wouldn't surprise me if anyone wants to entirely avoid shimano 12sp right now. I would personally go shimano 11sp if I were building a bike or upgrading right now.
 
I can see you're set on 12speed, and might as well go for it if thats what you want.

I'm throwing in +1 for Shimano 11sp. It was easy as it gets, using some spare parts from upgrading my other bike, with a few new things. Brakes, driveline and better shock brought the bike up towards modern standards and made it infinitely more fun to ride. Don't notice that it's 26". It's perfectly capable for XC and trail riding. After a while I bought a budget cassette and derailleur for a mates enduro bike. They are comically oversized for the purpose so I grabbed them for the XC and it's now at it's peak.

2010 Specialized FSR XC Comp
Drivetrain: Shimano 3x9 ➡ Shimano 1x11
RaceFace
Chainring: 32T NW 104 BCD, 2mm spacers, random suitable length chainring nuts/bolts.
Shimano
Bottom Bracket: BB-MT800 (New)
Cranks: SLX M675 2x10
Chain: SLX CN-HG601
Shifter: XT SL-M8000
Cassette: SLX CS-M7000 11-42T ➡ Deore CS-M5100 11-50T (New)
Derailleur: XT RD-M8000-GS ➡ Deore RD-M5100-SGS (New)

[Brakes: Avid Juicy 3 ➡ Shimano XT M8000]
[Shock: XFusion 02-RLA 190x45➡ Fox Float Performance Evol LV 190x51 (New)]
 
I don't know if this matters, but to some degree, showing up on a 26er will gain some instant respect but then seeing it converted to a 1x just looks like a dimwit that can't comprehend a front derailleur. I mean, everybody has their reasons, but as an old timer, speaking with embarrassment for this, but that kinda pops into my head when I see an old 26er that someone spent needless money to convert to 1x. And 1x 11 is one thing, but those expensive 1x 12 cassettes is just crazy. And I have a modern 1x 29er but still have my old 26er with grip shift vbrake 3x7 and that bike rocks. Still catches everyone on downhills on the local group rides.
 
I hear you. it cost me $400 to convert my bike to 1x11. cost money to convert from V to disc, and I had XT/XTR vees. I can totally get the idea that people might look at me on the trail like I'm a goober.

Gotta admit tho, I don't mind. I look like a goober when off the bike anyways. And having no FD and the dropper post on that bike is awesome. And I like to tinker, so the wrenching was as much fun as the riding. So I'll just goober my way along. only the experts will see me as a goober. Everyone else is focused on their own riding anyways.

And if I picked up biking because I wanted to "see and be seen", I think I'm probably doing it wrong...
 
I hear you. it cost me $400 to convert my bike to 1x11. cost money to convert from V to disc, and I had XT/XTR vees. I can totally get the idea that people might look at me on the trail like I'm a goober.

Gotta admit tho, I don't mind. I look like a goober when off the bike anyways. And having no FD and the dropper post on that bike is awesome. And I like to tinker, so the wrenching was as much fun as the riding. So I'll just goober my way along. only the experts will see me as a goober. Everyone else is focused on their own riding anyways.

And if I picked up biking because I wanted to "see and be seen", I think I'm probably doing it wrong...
People shredding with 26ers in 2021 (with any drivetrain) are awesome. So much more effort needed to pick lines and balance the shorter wheelbases.

I would hazard a guess that cheap 1x conversions like Microshift 1x10 and Deore 1x11 will appeal to a lot of people who have kept old 2x and 3x drivetrains on 26ers. If - 6 years after 26er mid/high range bike were last in bike shops - owners are set on keeping them going, a 1x it might be cheaper than replacing the 3 front chainrings and cassette.

I plan to ride my old Shogun 26er's 3x9 drivetrain into the ground then seriously evaluate Deore 1x11 as a replacement.
 
1 - 20 of 26 Posts