Lower gear for Devon hills

[Ajax Bay]

I'll not add to the various gear lengthening suggestions above, but

I'm planning on doing it myself so I assume I just need a cassette tool?

you will need a chain whip as well, to 'secure' the cassette while undoing the lock ring.
And once sorted, go and test it on the climb out of Lynmouth and confirm that test through and beyond the Valley of the Rocks to Combe Martin.
North Devon coastal bit of @Ian H 's route here:
http://www.ukcyclist.co.uk/maps/VoR.gif

 

[si_c]

Just as an FYI wiggle have an 11-34 cassette on offer which would work, if you have a long cage derailleur.

http://www.wiggle.co.uk/

As mentioned above you will need a cassette tool and chain whip as well and possibly a longer chain.

 

[8mph]

I come from Devon and went for a 24t chainring and 32t large sprocket and found that I didn't need my lowest 5 gears after a couple of months. Still, the low gears will get you going and you won't miss the big high gears much as you're hardly ever on the flat.

 

[DCBassman]

Agreed, I'm mostly on the middle ring, use of the inner has diminished considerably. But I still want to go down a little on chainrings for the Scott, and quite a bit on the heavier Norco.

 

[8mph]

In retrospect, I'm glad to have the low gears. I've recently replaced my 400g tyres for 700g tyres and put on a few kilos so the steel bike feels heavy again. I need to spin till I'm thin!

 

[DCBassman]

Yup, still needing to go down 8-10 kg, ideally.