gear ratios

magicbastarder

so i'm on a bike with probably 12 year old 105; 9 speed.
running 53/39 on the front, and 13-26 on the back; and the steepest hill i'd be up more than a couple of times is howth, from the village side, and i usually spend most of it in my granny gear.

is there much range of 9 speed cassettes which would allow a greater range than that? my concern would be that it might be too gappy in the gears i use most (generally 39-15 or 39-16 would be my go-to gears on the flat depending on how fresh i am/wind/etc.)
would cassettes with a greater range be a bit gappy in my sweet spot?
or would looking at chainrings be a better idea?

smacl

You can get up to 32t on rear handily enough but may need a new rear mech, and most likely need a new chain. Changing chain rings say to 50/34 would need a new crankset as the bolt pattern is different for standard and compact chain sets.

seamus

If you're managing the hills in the granny gear, then I don't see why you feel the need to give yourself more options?

As smacl says, larger cassette ranges bring some technical issues with them. Rear mechs have a maximum capacity, which is basically the amount of "spare" chain it can accommodate.
The mech's purpose is not only to shift the chain across the cassettes, but also to keep the chain tense by wrapping it up in the mech and altering the amount of chain available as it moves across the cassette. It's a wonderful piece of engineering really.

The consequence is that the larger the range of gears you have, the more chain is required to be kept tense by the mech. This is achieved by varying the length of the cage/arm on the rear mech. Short cages are typical on road bikes, medium on touring bikes and long on MTBs.

So if you want a big range (12-32 is big), you'll need a long cage rear mech. A short cage simply won't be able to keep your chain tense enough and in the lower gears, you'll find it flopping and skipping all over the place. The mech will work fine with your current shifters, but you'll likely find them more spongey and sluggish than you're used to. Short cages are stiff and snappy, whereas long cages are more flexible, and slower to change.

magicbastarder

seamus wrote: »

If you're managing the hills in the granny gear, then I don't see why you feel the need to give yourself more options?

it's enough to get me up howth from the village, not sure if i'd manage some of the tougher climbs around dublin on it.
the question was partly inspired by a GCN video:
https://www.youtube.com/watch?v=uwYCdNm7f0k

where they compare a compact to a standard chainset, and recommended 'appropriate gears for stupid climbs'. i.e. you end up less banjaxed at the top.

JMcL

I've a 12-27 9 speed with short-cage rear and don't find it too gappy (compact chainset though). That said, I've no aspirations for racing so don't care too much. I think a 11/12-28 will work with short cage, but wider than that you're looking at long cage (Shimano seem to refer to them as "medium" cage)

iwillhtfu

Get yourself a compact chainset if you want to take on a lot of hills your knees will thank you. I don't see a need for a standard unless you need a high top end speed i.e. racing.