Gearing

I have no idea, but in general, I would personally opt for a larger cog. The reason is that if you don't need it, you don't have to use it, and if it isn't there, you can't use it.

I would also guess that unless you are a strong climber that if you don't have a triple, you should consider it... with the same reasoning.

I ride with a 27 as standard equipment:o & don't have that much steep stuff where I generally ride. It's just handy when the going get tough. I'm 52 years old.

If your talking shimano 10 speed? 12-25 & 12-27 the last 3 cogs are 21-23-25 & 21-24-27 respectively. Seeing that you are going to do some fairly steep climbing there probably isn't much point with the 25 as the derailleur can handle the 27.

A new cassette on an old chain may cause other issues like slipping, so if the chain rings are ok, shout your self a new chain 🙂

dgregory57 said:

I would also guess that unless you are a strong climber that if you don't have a triple, you should consider it...

or what about a compact crankset?? thats if you wnat to go down the path of changing cranksets

IMO (allbeit without having climbed anything like that in my life) a 27 cassette should kill it.

good luck - am very jealous!

amattinson said:

I normally ride my entry level roady in hilly territory with several 4km ascents of about 5% with a 23-11 cassette. While not the best climber I don't think the gearing is the problem. I am going to a quite mountainous region (Switzerland) for work and taking the bike so as not to miss the oportunity of riding some of those awesome cols.
Anyway.... what gearing does anyone with any idea recommend or even just general opinion. I am considering 27-12 but wondering whether I need to go to the 27 or whether 25 will be sufficient.

See the gearing and get the 12-27. Nothing worse than needing a lower gear and not having one.

Lama said:

or what about a compact crankset?? thats if you wnat to go down the path of changing cranksets

IMO (allbeit without having climbed anything like that in my life) a 27 cassette should kill it.

good luck - am very jealous!

I agree, a Compact is an option, but if it were me, I would go for a touring (or maybe even MTB) triple.

I only do small hills, and I run a 50/34 and an 11-28 cassette... Of course, I am 50 and overweight.

I agree with some of the other posters......look into getting a compact. That's what I would do.