Cassette sprocket

Pinball72

Advise please, quite newish to road cycling.

I'm in the process of upgrading my groupset to a Ultegra 6800 11 speed system. Ive shopped around and found a complete set for just over £500.

My question is please, Ive noticed that there are a few different sprocket sizes available to buy -
11/23T 50/34, 11/25T 50/34, 12/25T 50/34 and 11/28T 50/34 - could someone please tell me what the difference each size does.

Thanks

nicklouse

http://bike.shimano.com/publish/content ... _road.html

11 or 12 is the small cog size and 23 or 25 or 28 is the size of the big cog.

monkimark

50/34 is the number of teeth on the big & small chainrings at the front - bigger number = bigger ring = harder/faster (although all the ones you're looking at are the same size.

11/23, 11/25, 12/25 & 11/28 are the rear sprocket sizes for smallest & biggest - bigger number = bigger cog = easier. 11/28 gives you the widest range of gears but bigger jumps between gears.

t4tomo

the 50/34 is the number of teeth on the front chain rings - known as a compact - thats absolutley fine.

the x/y is the smallest and largest sprockets on the rear cassette. a 12-25 is as good a choice as any unless you live in a very hilly area or you are not very good at climbing in which case the 11-28 is a better bet (for the 28 end).

count what you have now and make a choice from there depending on whether you find your current gear range OK or not

Anonymous

Its purely down to personal preference and what gearing you need, as opposed to what each does.
What do you have at the moment and how do you find it?

Guessing you have 50/34 chainrings at the moment, so you need to find out what size cassette you have and decide if you are happy with current highest and lowest gears.

You could just get the 11-28 and have the biggest range, but if you never really need to use either the 11 or the 28 then a 12-25 will have closer ratios which I would personally find nicer to ride unless it was very hilly.

ForumNewbie

With 50/34 compact chainset you are best with 11-28t at the back as it should get you up most hills. If you have 34/23 or even 34/25 as your lowest gear it will be hard to get up really steep hills, especially if you are new to road cycling.

mattv

11 speed cassettes don't fit on most pre 11 speed wheels though, so factor that into your costs.....

Wirral_paul

North Wales - so plenty of hills at anything up to 33% - i'd definitely go for the 50/34 and 11-28 for starters. I'm pretty local so know plenty of the hills in the area

DiscoBoy

Pinball72 wrote:

Advise please, quite newish to road cycling.

I'm in the process of upgrading my groupset to a Ultegra 6800 11 speed system. Ive shopped around and found a complete set for just over £500.

I take it that you mean Ribble at £513?
http://www.ribblecycles.co.uk/gsd/road- ... SHR&bike=1

Don't forget to factor in fitting/ tools for fitting, and you may also need new, 11sp compatible, wheels.

Oh, and:
http://sheldonbrown.com/gears/

Wirral_Paul wrote:

North Wales - so plenty of hills at anything up to 33% - i'd definitely go for the 50/34 and 11-28 for starters. I'm pretty local so know plenty of the hills in the area

Advising someone on what gearing to use without knowing how fit they are is like advising someone on shirt size without knowing what they look like...

Pinball72

Yes, its very hilly wirral_paul.

Thanks for the advice guys. I just wasnt 100% sure as to what to buy as I wanted a gear that would give me some kind of chance to ride thru the mountains of snowdonia.

Wirral_paul

DiscoBoy wrote:

Wirral_Paul wrote:

North Wales - so plenty of hills at anything up to 33% - i'd definitely go for the 50/34 and 11-28 for starters. I'm pretty local so know plenty of the hills in the area

Advising someone on what gearing to use without knowing how fit they are is like advising someone on shirt size without knowing what they look like...

A "Beginner" who hasnt ridden enough to know the meaning of gear ratios yet and who lives in a hilly area like North Wales which i happen to know extremely well - safe to say i'll be right most of the time. I cant imagine Pinball72 is going to be 1st or 2nd cat - you think he's likely to be otherwise then Discoboy??

lc1981

ForumNewbie wrote:

With 50/34 compact chainset you are best with 11-28t at the back...

I don't really understand this. A 34-tooth chainring provides pretty low gearing, so why would a compact necessitate a 28t sprocket? The OP may well be best off with a 28 in a hilly area, but it doesn't follow from having a compact chainset. If they had a standard chainset, then a 28 might be more necessary.

rolf_f

lc1981 wrote:

ForumNewbie wrote:

With 50/34 compact chainset you are best with 11-28t at the back...

I don't really understand this. A 34-tooth chainring provides pretty low gearing, so why would a compact necessitate a 28t sprocket? The OP may well be best off with a 28 in a hilly area, but it doesn't follow from having a compact chainset. If they had a standard chainset, then a 28 might be more necessary.

You go and ride up a 25% gradient with a 39-28 and then do it a few more times and cycle 100 hilly miles in between and then say you can't see any point to 34-28.

If I was the OP I'd be going for the 50-34 and 11-28 without a moments hesitation.

lc1981

I'm not saying that there's no point in having a 34-28 bottom gear. I'm saying that having a compact isn't what necessitates a 28 - it's the hills that necessitate it! Perhaps it's just how ForumNewbie worded it that confused me.

Wirral_paul

lc1981 wrote:

I'm not saying that there's no point in having a 34-28 bottom gear. I'm saying that having a compact isn't what necessitates a 28 - it's the hills that necessitate it! Perhaps it's just how ForumNewbie worded it that confused me.

I'd say its more the cut in the quote that is the slight confusion - the full quote of "With 50/34 compact chainset you are best with 11-28t at the back as it should get you up most hills." which i think is a pretty fair comment to make to someone living in the Snowdonia area (unless he goes to ride up Prenteg!! ). The bottom gear of 34-28 is pretty low and most will manage with that - although some no doubt would need lower, and some wouldnt. I have 34-27 on my summer bike and 30-25 (Athena triple) on my winter / touring bike which will give approx the same climbing gear ratio.

lc1981

Yes, but even the full sentence makes it sound like the need for a 28 stems from having a compact. Anyway, enough about grammar.

DiscoBoy

Wirral_Paul wrote:

DiscoBoy wrote:

Wirral_Paul wrote:

North Wales - so plenty of hills at anything up to 33% - i'd definitely go for the 50/34 and 11-28 for starters. I'm pretty local so know plenty of the hills in the area

Advising someone on what gearing to use without knowing how fit they are is like advising someone on shirt size without knowing what they look like...

A "Beginner" who hasnt ridden enough to know the meaning of gear ratios yet and who lives in a hilly area like North Wales which i happen to know extremely well - safe to say i'll be right most of the time. I cant imagine Pinball72 is going to be 1st or 2nd cat - you think he's likely to be otherwise then Discoboy??

As a beginner, I didn't know anything about gear ratios and managed just fine with 34-25 lowest, and that's including unsupported touring with a tent. Remember that people who are new to cycling come in all shapes and sizes, and that there is a lot of difference between a 90kg mamil who is new to cycling, and someone who is younger, fitter and lighter.

p.s. You aren't the only one from North Wales

Anonymous

Just get the damn 11-28.
Cassettes don't last forever and you can always get a closer ratio one next time when you better know what you need.

If you are such a newbie to not know wether you need an 11 and/or 28 sprocket then having a slight spread on sprocket sizes is not really going to matter.
Its 11 speed so one of them is an extra anyway lol.

mattv

Except, as I pointed out above, a 6800 11 speed group will NOT FIT a large proportion of wheels without a new freehub body and re dishing the wheel, if even possible.

simon_masterson

DiscoBoy wrote:

Wirral_Paul wrote:

DiscoBoy wrote:

Wirral_Paul wrote:

North Wales - so plenty of hills at anything up to 33% - i'd definitely go for the 50/34 and 11-28 for starters. I'm pretty local so know plenty of the hills in the area

Advising someone on what gearing to use without knowing how fit they are is like advising someone on shirt size without knowing what they look like...

A "Beginner" who hasnt ridden enough to know the meaning of gear ratios yet and who lives in a hilly area like North Wales which i happen to know extremely well - safe to say i'll be right most of the time. I cant imagine Pinball72 is going to be 1st or 2nd cat - you think he's likely to be otherwise then Discoboy??

As a beginner, I didn't know anything about gear ratios and managed just fine with 34-25 lowest, and that's including unsupported touring with a tent. Remember that people who are new to cycling come in all shapes and sizes, and that there is a lot of difference between a 90kg mamil who is new to cycling, and someone who is younger, fitter and lighter.

p.s. You aren't the only one from North Wales

Very much this. For about the first year I had no clue what chainrings or sprockets I had. Not suggesting that 34x28 is inappropriate, but we're all different, and not everyone is a nutter when it comes to hills.

But jumps can be coped with. I use 5 speed, and whilst it's annoying at times that I have a choice between 14, 16 and 20, I can't say it keeps me awake at night. People these days are just pampered because you actually can have a cassette with close ratios that starts at 12 and ends with a vaguely easy climbing gear.

ForumNewbie

lc1981 wrote:

Yes, but even the full sentence makes it sound like the need for a 28 stems from having a compact. Anyway, enough about grammar.

I don't think there was anything wrong with my grammar. The OP was asking which was best "11/23T 50/34, 11/25T 50/34, 12/25T 50/34 and 11/28T 50/34 - could someone please tell me what the difference each size does.".
As in each example he was specifically quoting a 50/34 compact chainset, I think it was reasonable for me to suggest that with that compact chainset that the 11-28 cassette would be best to get up most hills.

lc1981

I still don't really get it. Why does a compact require a 28? Surely having a compact makes it less likely for someone to need a cassette with a 28 sprocket? Unless you would recommend a 32 or something for a standard chainset? Anyway, doesn't matter.

ForumNewbie

lc1981 wrote:

I still don't really get it. Why does a compact require a 28? Surely having a compact makes it less likely for someone to need a cassette with a 28 sprocket? Unless you would recommend a 32 or something for a standard chainset? Anyway, doesn't matter.

A compact doesn't need a 28 sprocket. All I was saying that a 34-28 lowest gear would be better for hilly areas than a 34-25 or 34-23 lowest gear, as the original poster was asking about these gears. I wouldn't want a standard chainset as it would just make the hills a lot harder - probably why most bikes you see advertised these days have compact chainsets.

lc1981

Yes, that makes more sense.

Mikey23

My 34 28 is well worth it here in cornwall. Probably not so useful if I'd have moved to East Anglia when I had the chance!