Best ratios - buying new groupset

Mcreighton90

Hello,

I am going to buy a new groupset for a long distance tour - I don't have much knowledge about which ratios are best. I was thinking of going 8 speed rear and just need a double at the front, but I don't know about teeth sizes/numbers and chain lengths etc.

Hope someone can advise,

Cheers.

k-dog

8 speed would work - although 9 won't be a lot more expensive.

For a tour you probably want a triple on the front. Long climbs are a lot harder with a load.

dgunthor

i'd go 10 speed compact - 50-34 chainset and 12-28 cassette, you could even put a 30T sprocket on the cassette if you like - all the ratios of the triple but without the chainline issues

t4tomo

what's your budget and what have you got at the moment? If you can and want to reuse the shifters that will save you a chunk of money.

rhext

The traditional way to size a chain is to wind it round the largest cog at the back and the front (not through the rear mech), stretch it tight and then add two links (or one, if you're going to add a powerlink). There's lots of advice on the internet, including videos, and it works a treat.

Be careful making sure you get the right size rear mech....there are three options: short, medium and long cage. The difference between them is the number of teeth of slack that they can take up. so if (for example) you had a 50/34 on the front, that generates 16 teeth of slack, and a 25/12 on the back, that's a further 13. So you need a rear mech that's rated to take up at least 29 teeth. When your'e buying your mech, in the specification it will tell you what it's rated for.

If you're going on a long tour, you probably want to concentrate more on making sure you've got enough lower gears rather than worrying too much about spinning out on the descents.

drlodge

rhext wrote:

If you're going on a long tour, you probably want to concentrate more on making sure you've got enough lower gears rather than worrying too much about spinning out on the descents.

Pretty much this ---^ I would start with the lowest gear ratio you'll need and then work back from that e.g. do you need 34x25, 34x29 or even lower in whch case you're into triple chainring territory.

I've got 34/50 chainring and 12-27 cassette which gets me up short 20% hills, but if you have luggage and are travelling up longer climbs, then a lower gear is a godsend.

Mcreighton90

Thanks for the advice - thing is I'm a bit of a ski bum...so the budget is low! I was just thinking shimano sora complete groupset. At the minute it's an old campag 6 speed, with what I think are 6 speed shifts/brakes.

There are a few options for ratios of cassettes with the sora, I may just go for the one with the lowest for the climbs then.

cycleclinic

Why not stick to 6 speed and se a 14-28T caseette. Cahnge the chainset to a triple like a Shimano 2303 and fit a triple front mech and that will be a lot cheaper.

Nowt wrong with sora though. there is also the 2300 series. There is a fair bit of choice with 8 speed and replacement parts are cheap.

rhext

Oh, almost forgot, if it's a Campag 6-speed you should probably check freehub compatibility before you buy a Shimano groupset, or you might find the cassette doesn't fit your back wheel. Fairly sure an old Campag freehub won't fit a Shimano cassette.

southdownswolf

Changing the whole groupset from Campag to Shimano could be a pain in the backside, as rhext points out, you will probably need to change the rear hub/wheel.
Would you not be better of sourcing second hand Campag parts?
What cassette and chainrings do you currently have on the 6 speed?