single chain ring (tiny)

[jonny jeez]

Sorry for the ignorance but I noticed a big selection of MTBs in my lbs. today that had a single chain ring, which was tiny along with some massive sprockets in the cassette.

Is this the next new"thing" in the MTB world ? And what are the benefits?

Just very curious.

 

[KneesUp]

The single chainwheel 'thing' appears to have the following arguments:

1) Setting up a front derallieur is 'fiddly' - with 1 chainwheel you don't have to do it (I believe this is because with more and more cogs in the cassette, it's harder to index the front across the whole cassette than ever, and your modern changers don't allow for trimming)

2) Now you can get a gazillion speed cassettes, you can get a wide gearing range with only one chainwheel

3) It's lighter, innit? No FD or changer

4) It's 'fashionable' so the manufacturers can charge the same for the bike but don't have to pay for one gear changer, a front derallieur or one or two chainrings

No idea why it's small and large though - maybe it's because your modern kids are unfit?

 

[Yellow Saddle]

It is the latest craze and called 10 x 1 or 11 x 1 by those on the know. You can make up your own reasons but I think the list above does the trick. If you take a closer look at the chainring you'll notice that it is different. It has fat and thin teeth which fit perfectly into the chain's fat-thin square holes. This tight fit prevents the chain from coming off even in extreme cross-chain positions. But if you think about it a bit, you'll see that the differential teeth cannot work on a double or triple, only on a single where the perfect synchronization between fat and thin can be guaranteed.
The 11-speed cassette fits onto a new freehub standard but which is just as wide as standard MTB OLDs. This places the large sprocket well inboard, so far inboard that it needs a large central cut-out so that the spoke cone profile can actually sit inside it.
From a single shifter the rider can now make shifts all exactly the same incremental size from each other for ....you guessed it..."a smoother pedal strike under all conditions" and you guessed it again...for "better performance and more podium finishes" blah blah blah.
Coupled with Shimano's XTR electronic shifting the rider now just has one button (two actually but on the same side) to keep on pressing to make those podium finishes.
11 x 1 doesn't give you all the options a 3 x 10 or 2 x 10 gives you but then again, you are a super athlete that doesn't require all the options. If you are a slightly lesser athlete you can still go for 2 x 10 and set your XTR electronic shifting up to automatically change front and rear for perfect sequential shifting from one button.
There you go, and you didn't even know you needed electronic 1 x 11.

 

[Deleted member 23692]

All of the above, plus...

With a clutched rear mech chain retention is so good you only need a chain device if you're on very very rough ground.
The smaller chainwheel gives you a bit more clearance over rocks, and roots etc.
The lack of a shift lever on the LHS handlebar frees up space for lock outs, shape shifters and dropper post controls.

I run a 1x10 with a 32 oval chain ring on the front and 11-42 cassette. I've got a great spread of gears for off road use, but it lacks a bit when on tarmac.

 

[Funkweasel]

It's just better. I love mine.

 

[Dogtrousers]

What does a "clutched rear mech" do? I've seen them mentioned in print, normally with reference to very wide range cassettes.

Just curious. I'm not wanting to rush out and buy one.

 

[Deleted member 23692]

It adds tension to the pivot on the cage, so it's harder to move forwards and creating play in the chain when bouncing about over rough ground. Rearwards movement isn't affected tho, so slack is taken up just as quick. I've not dropped a chain since fitting one. It does make shifting up the cassette a wee bit harder, and my thumb does start to notice it on a long ride.

You can use a normal mech on a 1x, but you'd be wise to run a chain device if you're going near rough stuff.

 

[jonny jeez]

Thanks guys, interesting.

I know nothing about this, other than what you fine people have just told me. So now I am happy to make a few comments without fear of looking totally daft. From a position of ignorance, it's seems there are a couple of extra benifits to me. First, there is no longer any need to feel embarrassed to use the small chain ring (not sure that embarrassment exists in the muddy side of cycling, I've been away from The MTB world too long to know).

Also and perhaps more relevant, I find on my bikes (MTB and road) that there are a few gears on each chain ring that seem a little duplicated and as such are a bit of a waste. I rather like the idea of no front mech, no left lever and less wear on the chain (especially when I forget to swap rings under pressure on a steep hill.)

Lastly, with the size of brake discs on MTBs these days, the mahooosive block looks kinda right, sat on the opposite side of the spokes, offering some symmetry.

Could this be something that will filter into road bikes, or do you think that are there technical reasons why it can't...dishing and such like?

 

[jonny jeez]

@Ffoeg , @Funkweasel @Yellow Saddle @KneesUp .

While I'm in the asking mode. What's the thinking behind the different sized tyres these days. I get what fat bikes are for but why do some trail or cross country bikes now come with fatter rims and tyres.

Is this just a bleed in tech from fat bikes, or is there some science here?

 

[Motozulu]

All of the above, plus...

With a clutched rear mech chain retention is so good you only need a chain device if you're on very very rough ground.
The smaller chainwheel gives you a bit more clearance over rocks, and roots etc.
The lack of a shift lever on the LHS handlebar frees up space for lock outs, shape shifters and dropper post controls.

I run a 1x10 with a 32 oval chain ring on the front and 11-42 cassette. I've got a great spread of gears for off road use, but it lacks a bit when on tarmac.

This - exactly. I'll never run a front mech and multiple chain rings again - unnecessary clutter, weight and just another bit of kit to go wrong and more importantly - get clogged up with mud and cack.

Now my dropper button has lots of space, the bike is easier to maintain and clean, the guesswork is taken out of gear selection and I've not lost any noticeable range.

32 oval front, clutch rear mech, Sunrace 10 speed 11-42 cassette. Jobs a good un.

 

[Motozulu]

Tyres - it is a bleed down from fat bikes - those who have the + size tyres say the grip is stupendous - me, I haven't dabbled because I don't fancy the extra drag you will inevitably get.

 

[Yellow Saddle]

@Ffoeg , @Funkweasel @Yellow Saddle @KneesUp .

While I'm in the asking mode. What's the thinking behind the different sized tyres these days. I get what fat bikes are for but why do some trail or cross country bikes now come with fatter rims and tyres.

Is this just a bleed in tech from fat bikes, or is there some science here?

Sorry, I only saw this now. The debate about different sized wheels is as strewn with acrimony as a hot political or religious debate because at the end of it all, there's no science to argue this way or that way, just belief. The move to 29" wheels from 26" in MTBs has fuelled the industry with fresh sales. Go figure why it is promoted. The very fact that there is even a new size for fence-sitters tells me that even that market can be exploited. Hence the 650b re-introduction, this time to MTBs.

I don't think any come with fatter rims and tyres (other than fatbikes), it is more a question of new diameters.

 

[Motozulu]

But now you can actually - you are getting 650b+ wheels - where you can get 3inch tyres on a 27.5 rim.

Again, it's a halfway house between standard MTB rims and fatbike rims.

It's right in that it's all just another way to make you spend for the latest 'must have'. I won't do it myself as there is nothing wrong with the 27.5 2.35 tyres I am currently on - I don't need any more drag off fatter tyres for little gain.

 

[Nibor]

You can also run a narrow wide ring further enhancing chain retention.

 

[Motozulu]

Think someone else mentioned that earlier in the thread and yes, it's what I run - 32t narrow/wide oval (or thick/thin depending on manufacturer).

TBH with that set up, unless you are doing actual DH with big jumps - no need for a chain device. I've done Snowdon, Bowderdale, Peaks, BPW and all sorts of stuff and never dropped a chain once.