9 Speed Gear Ratios

Ridea10

I've just bought an entry level road bike which is equipped with 9 speed sora gearing on the rear (28-11) with a dual compact up front (50/34T). Whilst the bike is entry level and I'm certainly no powerhouse, I've been riding mountain bikes for about 13years so I'm no stranger to some pedalling. I've put in about 90miles on the bike now and find the shifts a little wide at times especially on long prolonged flats, I quite often felt like I was either having to power through or spin too fast. I also had a few climbs (nothing too mad) and whilst I did use the granny ring once when I ran out of juice, it did feel like more of a cop out than an actual need.

I was considering going to 26-12 or 25-11, thoughts & recomendations?

Riding wise it's fitness with an emphasis on I want to go as fast as possible (the very unfit racer in me) and generally 1-2hour rides or 30min blasts.

kj00

Can you estimate your cadence in that cases? Myself as a restarter not alwas can keep the optimal 90 rpm and think I must develop that. I am about to buy a new road bike, made some reserach and see that 50-34/11-28 is a rather common combination. Maybe not for top athletes but I have not checked that price range

flasher

I think I'd look at a 12-27, closer ratios where you need it.

Bobbinogs

Unfortunately, this is an "It depends" question/answer. One big factor will be the parcours on which you ride; rolling with just the odd hill coupled with a light weight but strong rider will mean you could get away with a small block on the back which will keep the ratios tight and help you keep an even cadence across the block. However, it could be that your cadence is relatively fast (so you naturally use more aero) or your cadence is slow (so you naturally use more strength)...it could be that your area is very varied...or not!

There is no magic science to cadence, but as posted above, many of us will aim for about 90-100 as an average. If you are hitting something around that and can get up the hills easy then pick smaller cogs at the back...simple as that.

I ride around the Cotswold escarpment which is a terrain that has a lot of variety from a nice rolling run around the floodplains below the hills to a lumpy route in the Wolds with plenty of 10%-20% brutes. I ride a 50/34 and 12-27...but that is what I have settled on after a little experimentation as a one size fits all. If I raced then I would choose a specific cassette for each race...but I don't, and running a compact setup would soon expose my feeble prowess and have me spat out the back on any parcours.

Why not have a go yourself and see what works, you might settle on an 11-23 or even a 14-25! Don't forget that you can fit a 6500, etc., so there are lots of options. Just work out the smallest combo you normally use (say 34/20), add one or two bigger cogs as bailout options (23 & 25) and then look at the ranges offered (so in the example, either 11-25 or 12-25 dependent on your cadence/strength). Remember that you cannot have a really big range without having bigger jumps so there is always a compromise to be had.

Alex99

Flasher wrote:

I think I'd look at a 12-27, closer ratios where you need it.

Agree, 12-27 is very useful. 13-25 if you want a tighter range. HG-50 cassettes can be had for under £10 if you hunt.

keef66

Yup, I'd say 13-25 would be a massive improvement given your description of what you want.

Ridea10

Ok perhaps I will go with my gut and drop to 26-12, I tend to use that on the rear of my downhill bike anyway so it can be a replacement if I don't get on with it.

I've never really thought about it in detail but how do the drops between sizes work?
For example: 28-11 is 28,24,21,18,16,14,13,12,11

So for a 26-12 does that mean 26,24,22,20,18,16,14,13,12?

In which case once you gain a bit closer spacing in the upto the middle of the block but mid to high is identical (other than the loss of the top gear)

And 25-12, 25,23,21,19,17,15,14,13,12?

Which if I'm correct gives much closer spacing all the way upto the final 3 gears but again losing top gear and almost losing an entire gear the other side for getting up those steeps...

N0bodyOfTheGoat

SJS list the sprocket sizes for different Shimano 9-speed options...

https://www.sjscycles.co.uk/cassettes/1 ... -cassette/

The steps between adjacent sprockets is more about percentage change than anything else. The 8-speed "megarange" 11-34 that came on my Wazoo meant a horrid jump from 26-34T, the change to that easiest gear is not exactly crisp! Much nicer on my 11-30, with just a 26-30T jump for my bailout, which I've not had to touch since installing.