Changing a cassette and chain - First time

Omega28

Instead of going to the bike shop I'm changing my cassette and chain on my road bike, which I know is an easy enough job.

However, I'm a bit confused when it comes to the actual cassette and gearing ratios.

The current cassette on my bike is a Shimano CS6800 Ultegra 11 Speed. When I look online for a replacement cassette I can find the same one but with many different gearing ratio cassettes such as 11-23, 12-25, 14-28 etc and it has me a little confused to which one I purchase for my own bike.

And I'll also be changing the chain, which I believe is good practice while replacing the cassette. Will any 11 Speed chain work?

Thanks

magicbastarder

how much wear is on your chain? you'd usually go through two or three chains before replacing a cassette, unless the chain is excessively worn.
your best bet re replacing the cassette is to replace like with like, unless you specifically want easier gears in the hills, etc.

regarding chain wear, you can buy chain checkers for around a tenner usually which will tell you how worn the chain is. decathlon or halfords stock them if your LBS don't.

Omega28

magicbastarder wrote: »

how much wear is on your chain? you'd usually go through two or three chains before replacing a cassette, unless the chain is excessively worn.
your best bet re replacing the cassette is to replace like with like, unless you specifically want easier gears in the hills, etc.

regarding chain wear, you can buy chain checkers for around a tenner usually which will tell you how worn the chain is. decathlon or halfords stock them if your LBS don't.

I've attached the image of the cassette. Also, the chain keeps slipping off and making a loud noise.

Omega28

magicbastarder wrote: »

how much wear is on your chain? you'd usually go through two or three chains before replacing a cassette, unless the chain is excessively worn.
your best bet re replacing the cassette is to replace like with like, unless you specifically want easier gears in the hills, etc.

regarding chain wear, you can buy chain checkers for around a tenner usually which will tell you how worn the chain is. decathlon or halfords stock them if your LBS don't.

Well, I don't know for sure how much wear is on the chain but my LBS said the chain needs replacing. They also said the cassette is done with the chain.

I uploaded a picture of the cassette. I don't know for sure if you can tell if there's much wear on it?

magicbastarder

it's very hard to tell how worn a cassette is, but a chain checker can easily check the chain. if the chain is more than 1% worn, i'd replace both, but if it's under 1%, you might get away with just replacing the chain (i usually replace mine just before they get to 0.75% usually)

magicbastarder

Omega28 wrote: »

They also said the cassette is done with the chain.

if you replace your chain before it's *too* worn, it's throwing good money after bad to replace chain and cassette together. if they're saying it's standard practice to replace both together, i'd be looking for another LBS.

however, as above - if the chain is badly worn, it's likely to have excessively worn the cassette too. have you any idea how many km are on the chain and cassette?

Omega28

magicbastarder wrote: »

if you replace your chain before it's *too* worn, it's throwing good money after bad to replace chain and cassette together. if they're saying it's standard practice to replace both together, i'd be looking for another LBS.

however, as above - if the chain is badly worn, it's likely to have excessively worn the cassette too. have you any idea how many km are on the chain and cassette?

Well, I've had the bike over 2 years now. It's a Cervelo S2. This will be the first time the chain and cassette will be replaced. The only other thing I've changed are the gear/brake cables and pads front /rear. Tyres.

During the lockdown (March onwards) I was cycling 500-650km per week until end of July. Prior to lockdown, I may have only been cycling 100km every week or so. I would guess around 5,000 - 6000km in total so far on the chain and cassette

07Lapierre

Omega28 wrote: »

Instead of going to the bike shop I'm changing my cassette and chain on my road bike, which I know is an easy enough job.

However, I'm a bit confused when it comes to the actual cassette and gearing ratios.

The current cassette on my bike is a Shimano CS6800 Ultegra 11 Speed. When I look online for a replacement cassette I can find the same one but with many different gearing ratio cassettes such as 11-23, 12-25, 14-28 etc and it has me a little confused to which one I purchase for my own bike.

And I'll also be changing the chain, which I believe is good practice while replacing the cassette. Will any 11 Speed chain work?

Thanks

count the teeth on the largest sprocket of your cassette.. from your photo, id say its a 25-11

lissard

Just make sure you have the right tools. For cassette removal you need a chain whip and a cassette removal tool. I picked up a cheap set on wiggle. There's a bit of knack to using the chain whip and I'd recommend looking at youtube before you give it a try.
https://youtu.be/7-MYHOpzT5A

lissard

On the chain, any 11 speed chain will work. What you buy will be longer than the one currently on the bike, you will need to trim it to the length of the current chain. To do this you need a chain breaker, most multi-tools have them built-in. On the chain, I have a preference for KMC as their 'missing link' chain connectors are really easy to fit. Shimano one's are a pain in the ass.

coddlesangers

You don't need to count the teeth, the no of teeth are etched into each cog in the cassette, so simply read what the largest cog is, given your spacing it looks like either a 25 or a 28...

Macy0161

My LBS, through a couple of mechanics, has changed just the chain, but warned you may need a new cassette but to try it fwiw.

Tony04

This is a very easy job once you put cassette spacers on correctly and put the chain the right way.
You can check cassette wear by inspecting the tooth profiles if the tooth profiles appear burred you need to replaced it. Although you best googling images of a worn cassette to see how it would look.
In your case id advise replacing both if you say its skipping. Generally i would say if your chain snapped is skipping or looks really manky, not mantained properly, than i would say replace both. Its not worth skimping it here as youll hust keep wearing out new chains.
The thing ive found with cassettes is once chains reach a certain wear point, wear accelerates very quickly. Thats why if you keep on top of you maintenance you can get through a couple of chains on your cassettes where as neglect it and you will only get through one.

In terms of gearing the bigger the sprocket the less the wheel rotates every turn of the crank so therefore youre going slower at the same cadence but also making less effort. Vice versa for the smallest.

Cassettes offer a good opportunity to customise your bike. If your racing an 11 23 cassette offers good shifting, as theres not gaps between shifting, and allows you to fine tune your cadence as the small difference in sprocket size lets you find your sweet spot. Where as an 11 32 cassette will be more jumpy but if youre heading to wicklow every weekend will make your rides alot more enjoyable. Be careful though all derailleurs are limited to cog size.

Buy a chain with a quick link and after that its up to you.

You can get cheaper tools, just read reviews, and theyll probably last. Also chain whips and cassette removers with longer handles are easier to assemble/disassemble

If i was to reccoment you a tool however Id reccomend this cassette wrench over a chain whip as its much easier to use believe me, pricier though. https://www.bikeinn.com/bike/unior-cassette-wrench/137499870/p