What is the biggest cassette i can fit?

tonewalk

Hi

I have a compact front ring (50/34) with a Campagnolo Record / Chorus set of gear components:
My question:
What is the largest size that I can have on the rear gear rings? e.g. 12-27?

I currently have a 25 as the largest rear, but wondered if I could go slightly higher
(I know i should be able to get up any hill with a compact (34) on the front - but some of teh hills in the Lake District are really tough

Many thanks

dru

I had a 13-28 rear cassette on my campag compact without any issues. Chain length was just about ok to not require a new one or extension.

Not sure about whether or not the rear mech you have would be compatible regarding short or long cages.

tonewalk

28 - great
Thanks a lot

gkerr4

the 'official' line is that anything bigger than the 13-26 cassettes should have a medium rear mech - the only one they make bigger than this is the 13-29 - however I have heard that even it can run OK if you avoid the extreme ratios - i.e. 50x29 or 34x13

tonewalk

ah.... a local (i'm in Lytham)

Can't see why you'd ever have it on 34/ 13 - if you were on 13 at the back -- you'd surely be on the 50 at front rather than on the 34

Most important (to me) is to have a high enough gear e.g. 34/ 27 (or higher) etc
so that the hills (not near Lytham I know) - are doable e.g. lakes / pennies

Did my 1st ever sportive last month - 03.10.09 Tour of Pennines and the hills and incredibly strong wind meant it was a tough tough day

Thanks

gkerr4

Hello! - not a lot of cyclists around here really - although I sold some wheels to a guy from cypress point the other day (I'm from singleton really too)

no - I can't see why you would use thr 34/13 either - although the 50/29 might get used occasionally. The alternative is to buy a new medium cage rear mech which will work fine.

well done on your first sportive! - any events planned for next year?

tonewalk

small world - I'm also from Cypress Point (but didn't buy the wheels)

I think i'd like to do 1 sportive per month - April to Sept (thats the plan)
Nothing booked though. May try the "Cheshire Cat" first
That Saddleworth .pennines event was really hard - although many 'seasoned' riders said it was the wind rather than the hills that created the difficulty (there were plenty of non-finishers)

And you? Plans for next year?

ColinJ

tonewalk wrote:

ah.... a local (i'm in Lytham)

Can't see why you'd ever have it on 34/ 13 - if you were on 13 at the back -- you'd surely be on the 50 at front rather than on the 34

Most important (to me) is to have a high enough gear e.g. 34/ 27 (or higher) etc
so that the hills (not near Lytham I know) - are doable e.g. lakes / pennies

Did my 1st ever sportive last month - 03.10.09 Tour of Pennines and the hills and incredibly strong wind meant it was a tough tough day

Thanks

The easy gears are the lower ones not the higher ones. It refers to the ratio of the number of teeth on the chainring to the number of teeth on the sprocket (cog on the cassette). E.g. 50/12 is a high ratio and a hard gear, 34/27 is a low ratio and an easy gear.

I've got a 13-29 cassette on my Cannondale but I only have a 39 little ring so I find the lowest gear still too high for some of the hills round here. I have a triple on my Basso and my lowest gear is 30/28 which is great for the hills.

markmanner

I have 2 bikes with a 50/34 front and 12-29 rear (I swapped out the 13 for the 12 in a regular campy 13-29). Although a medium cage rear derailleur is sometimes suggested for this setup, they work just fine with the standard cage rear derailleur. The standard cage rear derailleur shifts to the 29 tooth cassette with no problems. You do need to be a bit more careful in making sure the chain is the right length with the regular cage rear derailleur, since it doesn't have the same ability to take up slack as the medium cage derailleur, and balancing having enough chain to allow you to use the 50/29 without too much slack when it is in 34/12 is a bit tight (not that you want to use those combos, but when you are tired or distracted you might accidentally shift into them).

Mister W

My GF runs a Campag compact with a 13-29 cassette. You have to wind the adjustment screw a long way to ensure the mech clears the bottom two cogs but it works fine. She's got a longer cage mech so there's no issue with taking up the chain slack but, as Mark says, it is worth making sure the chain is exactly the right length.