Rear Cassette ratios- effect on pedalling

[Mortiroloboy]

I currently run Campag Centaur 10 spd , with a compact 50t 34t chain ring and a 11t 25t rear cassette. I don't use the 11t, the smallest I go to is the 12t. I was considering a change of rear cassette, campag do 12t 25t,
13t 26t,13t 29t.

My question is due to the loss of the 11 and 12t cogs would I notice a big difference suddenly starting at 13 rather than 12? I want the bigger gear for climbing so should I go for the 13t 26t, or the 13t 29t? Bearing in mind that I run a 50t 34t up front.

Your thoughts are appreciated.

 

[Will1985]

If you go for 13-29, you'll also need to change your rear derailleur to medium.
For flat riding, I use 11-23 which is fine for fairly flat Norfolk, but also have 13-26 for hills elsewhere. Sometimes in the UK I find myself wanting another gear on a steep hill. I think the difference between a 25 and 26 is about 4 gear inches. At the other end, I think I notice a difference between 11, 12 and 13. You can still manage 45kph+ at a cadence of 95 in the big ring.

 

[Mortiroloboy]

Hi Will, and thanks for the prompt reply, so If I go for the 13 26 I should be able to keep my exisiting Short RD? But will I miss the 12t? I'm no speed merchant, but can manage 27-30 mph on flats in the right conditions, albeit for short distances.

 

[Tim Bennet.]

A top gear of 50 x 13 is fine for most riding. You will 'spin out' when hammering hard down continental hills, for example, but it's still good for well over 40 mph. In places like the Dales and Lakes you'll probably never miss it.

It's been a very common combination for years, especially on Campag equipped bikes and round here I have 13-26 on everything.

 

[Smokin Joe]

I use a 13-26 here in Wales, also combined with a compact. Like Tim says, you will not really miss the 12 sprocket. Your existing rear mech will be ok with a 26 sprocket, in fact on my winter bike I run a 28 with a short cage.

 

[yenrod]

http://www.i1.net/~dwolfe/gerz/

Gear ratio chart...

 

[amrushton]

http://www.i1.net/~dwolfe/gerz/

Gear ratio chart...

Go on a favourite long ride and see how often you use those top 3 gears. i almost guarantee that you will use them less than 10% of the ride. if you race i can see you might use them, but for just riding about,a 13 tooth is as big as you need imo

 

[Mortiroloboy]

http://www.i1.net/~dwolfe/gerz/

Gear ratio chart...

Go on a favourite long ride and see how often you use those top 3 gears. i almost guarantee that you will use them less than 10% of the ride. if you race i can see you might use them, but for just riding about,a 13 tooth is as big as you need imo[/QUOTE]

I have just returned from AW Cycles in Caversham Reading, from where I purchased my Wilier , I had a chat with the mechanic and Jeff on the subject, in order to get the 13t 29t rear cassette I would have to buy a new RD at £70 plus £50 for the cassette, in their opinion there wasn't much point in just replacing the 11t 25 t for a 13 26, their advice was to stick with the set up as it is and just concentrate on improving my climbing, as I don't like parting with money unecessarily, I'll take that advice and try a bit harder.