ive just bought a new cassette and chain to replace the worn out bits on my bike .

I have just come to change this cassette and noticed the new one is a 11-34 as opposed to the 11-32 that im taking off??

will this make much difference to the gearing or not?

Also, as the cassette is slightly bigger will i need some extra links in the new chain im putting ?

sorry if it sounds a bit thick but i just wanted to check!!

The gearing is slightly wider as you go up from the 11t though you will very quickly become used to it (this is asuming it is a shimano one). Yes you normally need an extra link or 2 so th ebest way is to wrap the chain around the big ring and the largest sprocket and then add 2 links to this.
I tend to then check mine one it is all fitted by looking at the rear mech when in the big ring and smallest sprocket to see if it is sitting right.

also check your rear mech as well, as the short cage ones aren’t supposed to used with the 34T cassette I believe

34 is a waste of time IMHO if you find yourself in granny/34 you will need the balance of a cat stay upright as you will only be doing 2MPH flat out spinning.

Also you might find that your top jockey wheel now fouls the 34 cog ( especially if you have a rapid rise mech. if you have low normal mech you might not notice this until you shift into the 34 cog!

My advice is Ebay it and by a 32 – although to be honest 28 is plenty – I am running a 11-28 Ultegra on my Cdale Prophet – and I find 28 is plenty low enough for the brecons and afan and abergorlech.

I’ve jumped from a 32 to a 34 and back to a 32 on one bike and never had an issue (didn’t adjust the chain length either). 34 is a bit overkill though most places.

Keep the 34! As for the chain – well you’ll have to remove some links whatever – always do this by putting the chain around the biggest chainring and cassette sprocket outside of the rear mech and then overlapping by 1 link. This works for long cage mechs but with a short one probably won’t be able to do the overlap as the mech won’t be able to take up the slack all the time.

granny/34 you will need the balance of a cat stay upright as you will only be doing 2MPH flat out spinning.

3.8mph according to my computer – i switched to a 34t and find i can get over obstacles easier on steep ascents – always drop to 32 or lower if finding it too easy or spinning back wheel but i’ve cleaned some stuff that i’ve struggled on in past albeit very very very slowly

edit ps good video on chain length on sheldon brown site also on shimano site will tell you if mech can handle 34T – called total capacity i think but can’t remember how to calc is it smallest rear plus biggest front?

whoops meant is it biggest rear cog plus biggest front? = capacity which you can look up for any derailleur

IME a 34 makes one a bit lazy when twiddling and isn’t that useful really, since theres not enough torque to carry spped in technical ups.

It isn’t that you just get a 34t one though all of the rest are different.
11-34T (as-group)
Sprocket Sizes 11-13-15-17-20-23-26-30-34

11-32T (aq-group)
Sprocket Sizes 11-12-14-16-18-21-24-28-32

I find that i tend to use 2nd and 3rd much more with the 11-34 cassette than i used to.

YOu can never have too low a gear. Its no problem to balance the bike at 2.5 – 3.5 mph

buy a double and run a 34 ,i ride everything in my big ring appart from the steepest climbs.

thanks for the replys!!

the cassette and chain are both sram (970 and 971 i think)

my rear mech is a sram x9 long cage so hopefully i wont have any problems.

cheers

steve

I have gone to XT 34 from a XT32 on one bike and have an XT32 on the other.
The 32 is way, way smoother.
Unless you have a 29er, or are cycling up Snowdon daily, stay with a 32.
Tim

In my current state of unfitness, I’ve found the 34 very useful!

I use 1×9 so a 34T is very useful for me – 1:1 ratio on the steepest climbs.
If I had a double or a triple though, I probably wouldn’t bother.

Less smooth, most definately.
Why are you looking at a 34?
As in where are you riding etc?
For me: I’ve been riding Dalby, Afan, Cannock and local trails, I have no need of the 34 nor the granny ring.
I did this 32-34 as it went onto a 29er, but it’s not as smooth, but helps on the hills as it keeps me out of the Granny ring on my local trails.
Tim

one has 34 teeth, one 32…..sometimes me and a mate ride in different gears going up the same hill, I have stronger legs, he sits cos he’s on a full susser…..

its just a cassette, no right or wrong, no better….no worse.

If anyhting, more teeth spread the load, last longer, but may be heavier……zzzzzzzzzzzzzzzzz

I find it quite hard to keep the front wheel down if the hill’s steep enough to need a 32T, never mind a 34T.

Keep the 34 man! I just switched, it’s a revelation. Those two teeth can be the difference between being able to ride up it and getting off and pushing.

Also, you might find you can stick in the middle ring and change about on the front less.

Snake. You couldn’t be more wrong – your argument is self-defeating in what you say, namely it makes a whole heap of difference as your text points out and a 34 will last less time as the gaps are more spaced out and so it’s less smooth = a more agressive, abrasive action.
Only by trying these things will one become aware of them.
On my 26er a 32 is far better better, way, smoother transitions and I don’t feel a need for the granny ring.
On the 29er, it’s a more even playing field with the 26er and this is on the back of having swapped to a 34 about 3 weeks ago so your question is timely and topical.
A 34 is not as smooth to change gear, especially under load on the hills and that’s important. More chainsuck too.
Tim

It always suprises me that people can’t understand that not everyone has the same fitness, abilities or even just riding style.

I know people who could ride any trail in the big ring but that doesn’t mean that everyone else should ditch their other chainrings, does it?

a 34 will last less time as the gaps are more spaced out and so it’s less smooth = a more agressive, abrasive action.

Do you really think that wear from shifting is what wears out a drivetrain? Wear from simply riding is massively more critical. A 34 will wear out slower than a 32 because there are more teeth though it’s a very small difference (as is the actual difference in shift smoothness – do you honestly complain that your bike shifts better in the small sprockets (where the differences between sprockets are small – usally 1 or 2 teeth) than in the big ones? LOL

Larger sprockets will if anything also reduce the likelihood of chainsuck at the cassette though again, this isn’t a real issue since the chain is being pulled off the sprokets by the chain tension from pedalling while on the chainrings, the tension is only provided by the tensioner (ie mech) and is a lot less.

(FWIW, my geared bikes have largest sprockets of 28, 32 and 34. There’s absolutely no difference in shifting.

The point being that whilst you might have one experience, I have another.
And having changed cassettes 3 weeks ago, I can only relate my own experiences.
I’d have 2x 32T on both bikes (as it was originally) but the 29er demands a slightly different approach.
Chain such on the 26 is non-existance, but on the 29er it’s not uncommon now.
I’m sure you’re not at all concerned about the relative differences in cassette wear or weight as it’s going to be marginal at best.
Question is simple: do you have to have the extra 2 teeth?
I did one one bike but not the other.
And there is a difference.
Tim

Yeah, but I’ve backed mine up 🙂

Plenty of people can feel something that they think should happen but that doesn’t always make it right…

A 29er is fundamentally different anyway – the leverage is different because of the different sized wheel isn’t it. Besides experience of chainsuck is down to many factors like chain age, sprocket age and usage and chainring age and usage…

Question is simple: do you have to have the extra 2 teeth?

It really depends. In the past, when I was fit, no, not at all. Currently being unfit, I find that I spent a lot of time on a weekend away at Afan in 22×34 and was pretty glad for anything that made it easier even if only marginally… Horses for courses as I said. You can’t make a blanket statement about whether a 32 or 34 is better for everyone.

i got a 11-34 on right now and a dura-ace rear mech and it’s not keen on the top two cogs at all….. anyone got an 11-28 goin begging?

i’m with clubber on this one!

Sorry ti29er if you think that chainsuck is related to cog size then I can’t take anything you say seriously

11-34 is too big a tooth difference for a standard Dura-Ace (ie road) mech (and possibly even for one designed for a triple)

I know… but it came free and looks the shit hanging off the back of me little hardtail…. like i said, just need a 11-28,

im hoping that as im a bit of a fatty the extra two teeth will come in handy on the up hil;ls i normally get off and walk on!!!

There is a lot of arguing going on on this forum lately isnt there!!!!

cheers for the info dudes

I said that moving from a 32 to a 34 has resulted in chain suck on one bike & that it’s noticably not as smooth.
This is a simple statement of fact. I’m not asking anything from you or stretching your imagination.
It’s a new-ish chain (6 weeks) so as previously stated, it’s an experience I share with you & fact.
If you then choose to then disbelive everything I might post is your business.
And yes, I have noticed a difference in smoothness and have stated this several times as otherwise I’d not have contributed to this thread.
This is after all what he wants to learn, so I share my recent experiences with you, collevtively, if you then think I’m lying or have a hidden agenda, again, that’s your issue, and should not detract from the experiences I have taken the time to share with you here.

Only trying a new cassette out on your bike on your trails with your fitness, power, ride-style etc will you better know if 34T are for you.
Perhaps you’d be good enough to let us know how you get on?

Tim

12-34 for me, I love the extra 2T at the back, it means I can ride pretty much anything. Also means less shifting at the front since I can stay in the middle ring for most normal “trail” riding.

No difference in shifting on any of my cassettes cos I knows how to set gears up… 😉

It’s a new-ish chain (6 weeks) so as previously stated, it’s an experience I share with you & fact.

Well a new chain on used sprockets/chainrings is one of the main causes of chainsuck…

34 for me as I use a 38 up front.

You simple can’t get chain suck from a cassette as you are pulling the chian off under high tension. You get chain suck on the chainset as the chian comes off under very low tension as it is only the spring in the rear mech that is applying it.
If your chain was being grabed by the cassette then it would snap. When a cassette wears you get rounded off teeth due to the way the power is applied to it reather than the hooked teath of a chainring.
I would just stick with it as it would be costly to sell it then buy anything else unless you are well off or really care about it like i said i prefer it as i tend to use 2nd/3rd a lot more as well as sticking in the middle ring.

I run both 32T and 34T cassettes on my bikes, I can’t say that I’ve noticed any difference in shifting performance between the two, nor any chain suck issues. Like several guys here I find the extra low gear useful, especially on the the heavier bike, as I’m not as fit as I was in the past. Can’t see how anyone can say it’s rubbish – it just comes down to whether it suits your bike and riding style.

sam42

can’t think of an easy fix though i’m sure someone will be along in a minute – a quick google says max teeth for an older Dura Ace rear mech is maybe only 27! its a high end road mech! – the shimano site will give totally correct up to date info as i thought it was 28 but i think it is a pain to use

also as mentioned above capacity can be an issue – stolen from a post on another forum is this excellent explanation had problems with this issue on my CX fugly thing and because don’t go fast fast i kept the 34 but switched the 12 to a 13 as this comes off on its own

“Take for example a bike with a front gear ratio of 42/32/22 teeth and a cassette ratio of 11 – 28
teeth. To calculate the front difference you have to take the number of teeth of the biggest
chainring minus the number of teeth of the smallest chainring. So calculation for front difference
will be 42 minus 22 is 20 teeth.

To calculate the rear difference you basically do the same: You take the number of teeth of the
biggest sprocket of the cassette minus the number of teeth of the smallest sprocket. So calculation
for rear difference will be 28 minus 11 is 17 teeth .

To calculate the total capacity of the system we take above values: Front difference (20) plus rear
difference (17) is 37 teeth.” thanks to some guy called max for making it simple

Durace capacity is 38 ?

goin from that… i should be able to get away with it just maybe…. I run double and bash up front 34-24 so that’s 10 plus the 17 from the 11-28 if i can coax it into running ok makes 27…. i’ll update when i get an 11-28 and have two useable top cogs… for now i’ll just man up and stay in 3rd.

I run 11-32 and was wondering about going to 11-34, however, to really see the benefit does anyone do an 17t chainring? 😉