Mountain Bike Reviews Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
62 Posts
Discussion Starter · #1 ·
looking to upgrade from 3x7 to 1x12, I understand wheel and bottom bracket stuff, but which brand should I use? A 51/50-10t rear cassette and 39t chainring up front.
 

·
viva la v-brakes!
Joined
·
2,441 Posts
I would first ask yourself if a bike that came with a Tourney crankset is worth investing a fancy new 1x12 drivetrain on. There are less expensive 1x11 options or you can DIY 1x10 or 1x9. Or maybe ride what you have for a while and plan a head for new bike time in the future.

A 39t chainring is pretty big for anything but flat ground or pavement use. Also, chainrings on a 1x drivetrain need to have an EVEN number of teeth and. Narrow-wide profile.

Good luck.


Sent from my iPhone using Tapatalk Pro
 

·
Registered
Joined
·
62 Posts
Discussion Starter · #3 ·
I would first ask yourself if a bike that came with a Tourney crankset is worth investing a fancy new 1x12 drivetrain on. There are less expensive 1x11 options or you can DIY 1x10 or 1x9. Or maybe ride what you have for a while and plan a head for new bike time in the future.

A 39t chainring is pretty big for anything but flat ground or pavement use. Also, chainrings on a 1x drivetrain need to have an EVEN number of teeth and. Narrow-wide profile.

Good luck.

Sent from my iPhone using Tapatalk Pro
Sort of had a weird plan to upgrade this bike, then eventually upgrade to a full suspension frame and move all the components too it. Anyway, are there any 50-10t 11spd cassettes? Or can I 'mix and match' cogs to make one?
 

·
Registered
Joined
·
1,488 Posts
Sort of had a weird plan to upgrade this bike, then eventually upgrade to a full suspension frame and move all the components too it. Anyway, are there any 50-10t 11spd cassettes? Or can I 'mix and match' cogs to make one?
To get a 10t small cog, you are going to need an XD driver for SRAM or a microspline for Shimano. And that's going to probably require a new hub/rear wheel, which is probably not going to be available in the axle format that you have.

Just noticed that you may have a freewheel on that bike, necessitating a hub/wheel upgrade with any derailleur upgrade. The "default" hub when you move up to a freehub is going to be a Shimano driver, which is going to limit you to NX (11) or NX Eagle (12), both of which will have an 11t small cog. Or Shimano 10/11 speed.

There are a bunch of obstacles to upgrading from low end to high end. Also, unless you buy a pretty old FS, maybe 50% of your upgraded components for this bike will fit on your new one as a current FS is likely to have a tapered head tube, boost rear spacing, etc.

NX is probably your huckleberry for this little project.
 

·
Registered
Joined
·
2,634 Posts
looking to upgrade from 3x7 to 1x12, I understand wheel and bottom bracket stuff, but which brand should I use? A 51/50-10t rear cassette and 39t chainring up front.
It sounds like your primary focus is flat trails and high speeds?

I do not know a lot about swapping component, however one things I feel like I understand to a degree is that if you are trying to fit new parts to an older bike, the parts that are available today that are forward compatible may not be comparable with an older bike.

The amount of money you'll need to spend to upgrade your bike with the potential future bike is expensive, and may not even stay compatible once you move forward.

As mentioned above with the XD or microspline hubs, you'll have to spend the same money again to update the new bike to use the correct hub for the larger range cassette.

If you focus is fast stuff and not much steeper terrain, a simple 1x10 with larger cog for the occasional climb may be the simplest upgrade and will be cost effective too.

There are a bunch of fine details that I don't understand when mixing and matching components so it's highly likely what I said is only partially true at best.

I think your gear choice is a bit off though, unless you're planning flat and fast stuff.

Also something to consider is frame clearance with the large diameter ring you're considering.
 

·
since 4/10/2009
Joined
·
34,601 Posts
This project is the definition of a rat's nest of cascading "upgrades". It's next to impossible to know how far you're going to have to go, but I can tell you that you're going to have problems.

A 39t chainring won't happen. Not in a narrow/wide 1x ring that'll hold onto that chain. Narrow/wide rings, by definition, only come in tooth counts in multiples of 2. If you were happy with a 28t or a 40t ring, you'll find other problems, too. You won't be able to fit a chainring that size on a mtb direct mount crankset. It'll be too big and will hit the frame (chainstays). You'd need a crank with a 2x spider at minimum (maybe a 3x), and run that chainring in the outer position. The problem there is that you're going to have a garbage chainline and that's going to create other problems for you.

As mentioned already, getting a 10t chainring is going to require a hub with an xd driver. You can get them for pretty much any axle width still. But it will either be very expensive, or it'll be used and hard to find. That puts you onto a Sunrace cassette most likely. You can also hold out for the new Box 9spd drivetrains with 11-50 cassettes.

Realistically speaking, though, this plan isn't really a good idea for this bike.
 

·
Registered
Joined
·
1,390 Posts
As stated, lots of hurdles...not likely to be worth pursuing.

1. Any cassette with less than 11T (GX Eagle) requires 'xD' hub which means you will need to either replace wheel or re-lace existing with a new hub. You could go with SRAM NX which is 11-50 cassette that may fit your existing hub but...

2. A 12spd cassette takes up much more axial room than a 7 spd cassette so you need to confirm your specific frame/axle/wheel setup will have room for it. Newer bikes have a wider span between each side of axle at chainstay to accept bigger cassettes.

3. 39T chainring is HUGE...go to sheldonbrown.com and use 'online gear calculator' to figure out where you are now at 3X7 compared to where you want to be with new tranny. I have 12spd GX Eagle and my chainring is 34 which many consider to be a tall gear.

4. The cost of 12spd cassette, derailleur, chain, shifter, crank/chainring will likely be way more than what your old school bike is worth. And you have no assurance these parts will be compatible with whatever replacement bike is in your future.
 

·
Registered
Joined
·
1,729 Posts
Many people have raised potential challenges. If you're happy with a 11-50 cassette from Suntour - which works with SRAM 12 sp stuff, and will probaly work with Shimano stuff - it means that you probably won't need to change your freehub
 

·
BOOM goes the dynamite!
Joined
·
6,209 Posts
This is not a good plan. Seriously, you'll spend twice the money and for half the value if you're lucky.

Ride your current drivetrain till it's dead and save up.
 

·
Registered
Joined
·
1,488 Posts
Among all the other problems, 12 speed requires a long-cage derailleur and can be fiddly as hell traversing 12 cogs from little to dinner plate. They require pretty fine adjustment and the long der is perfectly adapted to catch on stuff and mess up your fine tuning.

If you really want/need that range, it may be worth it to you. If you are just trying to get the latest and greatest, fugeddaboutit.

I'd probably stick with 1x11 and see if Shimano does a "better" job with 12 speed and how that all shakes out. Some of those limitations are kind of inherent and I suspect that 12spd derailleurs are just going to be pretty finicky.

This in reference to your next bike, as I think 1x12 is really a stretch for your current bike.
 

·
Guest
Joined
·
1,040 Posts
My kid got a Canyon mtn bike with SRAM 12 speed GX Eagle. After a world of hurt with two dead derailleurs, we are migrating it over to Shimano XT (so far we have the derailleur and shifter). The XT derailleur works ok with the SRAM shifter, but the XT shifter was a major improvement. I think he will buy a SLX cassette and new frehub body when the Eagle cassette is worn out; the replacement cost for the Eagle cassette is greater than the SLX plus new freehub (DT Swiss).

So, based on this, admittedly anecdotal, experience, I would recommend Shimano XT (or SLX) over the SRAM option, but if it were up to me, I would either stick with what I have and run it into the ground, or upgrade to Shimano 11-speed (more bang for the buck).
 

·
Registered
Joined
·
2,634 Posts
The XT 2x10 derailleur on my 29er is 6.5" clear distance to the ground.

The NX 1x12 derailleur on my 27.5+ is 5.25" clear distance to the ground.

The axle centerline is 1/2" higher on the 29er, so take that into consideration based on your wheel size. This could potentially net near 6" clear.

Both the NX 12 speed derailleur and XT 2x10 speed derailleur have a 4" distance between jockey wheels therefore making the cages nearly equal size (slight differences in casting, etc.

The XT body is childish in comparison to the monster NX body. Not to mention the XT (shadow) is tucked inside of my non-boost 2x10 chainstay. The NX on the boost bike sticks out a good 1/2" from the chainstay. Not only is there less ground clearance, but the thing also sticks out quite a ways.

Just things to consider if this is the path you decide on.

If it matters -NX cassette, 11-50 (I think it weights in around 800 grams) and 30t front ring. It's rare to spin out unless I'm standing and pedaling 25+ mph down a hill to maintain speed after a corner, etc.

Asking for a 38/10 is quite a high gear (you probably know that which is why you asked). If you want that high of a gear I'd suggest a 2x10 drivetrain.
 

·
since 4/10/2009
Joined
·
34,601 Posts
12 speed requires a long-cage derailleur
Just to clarify, not 100% true.

Shimano M9100 XTR has a medium cage derailleur option that's meant to be run as 1x on the 10-45 cassette. But only XTR. XT and SLX have 2 different long cage derailleur options. 1 is meant for 1x systems and the other is meant for 2x.

FWIW, after a few hundred miles on it, I don't think it's terribly finicky. It's been quite solid and reliable for me.

But for OP, that's beyond the scope. For his current bike, I don't think I'd go past 10spd if the drivetrain needed replacing anyway. And if the rear wheel does require a freewheel...screw that. I'd keep it as a 3x7 and just save for a new bike.
 

·
Registered
Joined
·
1,488 Posts
Just to clarify, not 100% true.

Shimano M9100 XTR has a medium cage derailleur option that's meant to be run as 1x on the 10-45 cassette. But only XTR. XT and SLX have 2 different long cage derailleur options. 1 is meant for 1x systems and the other is meant for 2x.

FWIW, after a few hundred miles on it, I don't think it's terribly finicky. It's been quite solid and reliable for me.

But for OP, that's beyond the scope. For his current bike, I don't think I'd go past 10spd if the drivetrain needed replacing anyway. And if the rear wheel does require a freewheel...screw that. I'd keep it as a 3x7 and just save for a new bike.
Yeah I should have said "entry level." Which is kind of what I meant by seeing what filters down the Shimano line over the next few years.

I just really meant to point out that 1x12 may not be the be-all, end-all for a newer rider.
 

·
since 4/10/2009
Joined
·
34,601 Posts
Yeah I should have said "entry level." Which is kind of what I meant by seeing what filters down the Shimano line over the next few years.

I just really meant to point out that 1x12 may not be the be-all, end-all for a newer rider.
oh, no, definitely not.

I'd rather be using an older 1x10 that's high end and cheap than a similarly priced bottom of the barrel 1x12.
 
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top