Cassette Ratios

emty

I need to get a new 9 speed cassette but am unsure about the different sizes.I would like more help to get up the hills in wicklow,not too bothered about going down the other side.Can anybody throw some light on this for me,
thanks.

Stark

The higher the highest number on the cassette is, the more help you'll have going uphill. The lower the lowest number is, the faster you can go on the downhill.

Chips Lovell

What have you got at the moment on the front and back?

chris85

There is bigger cogs on the 10 speed version of the shimano groupsets (105, Ultegra, Dura ace). They have 27 tooth versions available which is probably as good as it goes i think.

I have more experience on MTBs but i think the 27 teeth is about the max at moment. Also looking at getting a smaller ring on the crankset. If you are running on a double then get the triple.

for getting up the hills the smaller the ring on the front and the bigger the cog possible on th cassette.

What setup you using in terms of components?

Edit: I am presuming you are talking about road bike here and not MTB but correct me if im wrong

rubadub

http://www.sheldonbrown.com/gears/

kenmc

wiggle have a 12-27 9 speed
and a 12-27 10 speed
FWIW, I'm on a 12-25, with a triple on the front of 30/42/52. I think you're on a compact 34/53? according to Sheldons calculator the 34/27 would be very close to my 30/25... if you want you can try my bike on a hill next time we're out to see how it feels

doozerie

I have seen a 30- or 32-tooth cog on a racer in the past (only a couple of times though - it's ridiculously large, like a dinner plate). That is probably overkill though, unless you are going up a wall. Apparently, large cogs disappear from the shops fast in the weeks before the Wicklow 200, as lots of people buy them for the day, or so I was told by one of the bike shops once.

What size you need will all depend on your fitness, and your riding style. I've had a 28-tooth on my mountain bike in the past, and needed it when off-road, whereas on-road I have found a 25-tooth more than enough (with a 39 tooth front ring). But that's just me. Some people could probably do the Wicklow 200 with a 21-tooth, but obviously that is not for everyone. So what works for one person might not work for you, and vice versa. The only way to really find out what you need is to try a few climbs and gauge whether what you currently have is anywhere close to adequate.

Be careful of the implications for your rear derailleur too - if it has a short cage/body it may not be able to cope with a cassette that ranges all the way up to 27 (or whatever you decide upon), in which case you may have to replace it too.

emty

Thanks a lot for your replies just home after getting soaked(again) and its not as much fun on your bike in your good clothes!!