Gear Ratios

Hi everyone,

I know its all personal preference but I’m just curious about what gear ratios everyone is riding with.

I’ve changed mine a couple of times and I’m not sure if I’m happy with it or not.

My steamroller came with 48/19, which I then changed to 48/17. I upgraded my chain ring, chain & rear cog to 130bcd - 46/15.

dasffs ?



Yeah, do a search… this topic has been done a few times. But like you said it is personal preference. It’s based on where you live, how many hills/downhills there are and how manly your legs are.

Do some experimenting and you will find your sweet spot

Do A Search FFS.

edit. didn’t read whole post

No worries. will search for previous topics

Mods please delete thread. cheers

don’t worry that much, it’s not such a big deal, but there’s lots of good info in the older threads so they’re worth looking for.

You will also find people will be talking about gear inches.

Use this to work out what you have and what you need to get the inches you want. Currently you are running 80" which is pretty big but it might suit the kind of riding your doing.

Or rabbit.

49/19 with 28c tyres.

exactly 69 gear inches and 38 skid spots :smiley:

this chart helps.

^ about that denny trimble chart - it’s for 27" wheels.

for 700c, subtract 2 gear inches from what the chart says.

i used that chart for ages, thought i had stronger legs than i really did…

i have a question

whats the difference between having 42:15 and 48:17

the gear ratio for both is around 2.8
but apparently having a larger chainring and larger cog is different to having a smaller chainring and smaller cog

or have i heard wrong?

48:17 is slightly higher (by ~0.6gi)

but the main difference would be the skid patches. 42:15 has 5, whereas 48:17 will have 17.

there are also other factors such as drivetrain life, weight, efficiency etc.

oh ok
because i heard that its harder to skid if your chainring is higher
i guess its not true?

nah, its dependant on your gear ratio.

fuck yes

so ah, jonno, you think that ratio might be a good one?

about the ease-of-skid factor, i think an ok rule of thumb is to go below 70 gear inches if you’re going to use your legs as a brake all the time. unless you’ve got big man legs.

47/17 is my favourite ‘city’ ratio, a bit over 74". i’d rather go faster on the flat and use a brake occasionally. brake pads are cheaper than new tyres.

but yeah, there’s sooo many other threads on this topic.

There’s a blog entry on the surly site talking about the issue of same gear ratio, different chainring and cog sizes.

Eg. a 39/13 combo and a 45/15 combo will both feel the same and have the same number of gear inches, but you have different components.

Worth reading…