Fixed SS Gear Ratios

ROK ON

Some advice reqd please.
I am hoping to buy a fixie shortly which I will probably run as a SS.
My present commute is flattish with only one bump so to speak. Usually I commute on either 50 / 12 thru 15.

The fixie that I am hoping to buy is geared with 42/16.
I have worked for over a year at changing towards spinning as opposed to mashing so I am not worried about easier gear ratios. However a 42/16 seems excessive.

Questions
1 what gear ratios do folks here use on a fixie.
2 I presume it is pretty easy to throw say an 11 or 12 cassette on the rear wheel?

Lumen

I ran a 42/16 and 42/15 for a while. It was fine.

Knee issues and hills aside, if you run a massive gear you'll have problems pulling away from lights.

Vélo

I run 42/16. It came with the Langster when I got it. I find it fine but I know from previous threads a lot of people run higher.

I was thinking of changing it to a higher gearing but I might leave it until after the winter.

Highway_To_Hell

my Charge Plug came with a 42/16 flip/flop which I used as fixed for a year of so. Due to spinning out on the flat I decided to change the fixed cog to a 14 which is great for my flat commute but I am not too sure if it is doing my knees any favours and I might flip the wheel to the 16 SS for the winter months.

doozerie

I use 42/16 fixed and 42/17 single-speed. I initially used 42/17 fixed and it was okay except that I spun out on some of the gentle downhill slopes on my commute - I found that I could maintain up to about 44kph on a 42/16 before I spun out, if that is any guide (possibly not as there are so many variables involved).

I've been on single-speed for quite a while now, rather than fixed. Sometimes I'd like to have something a bit higher than 42/17 but that is actually quite rare and for the most part I find it ideal for me (it's about what I mainly used on my commute bike before changing it to fixed/single-speed). My commute has drags rather than climbs and a higher gear would be manageable but the commute is also riddled with traffic lights which means I'm stopping and starting a lot so a lower gear wins hands down. Anything higher than 42/16 fixed would probably have made my knees suffer more than was good for them, but that's just me.

niceonetom

48:17 is my gear of choice for getting around but I use 48:15 on occasion for a change (and for making lance maps a little more interesting).

13 is about as small a cog as you can get without getting into weird bmx stuff - no one really needs gears that tall anyway, it would just make every green light a chore to accelerate off from. ROK, part of the rationale for denying yourself gears is to expand the range of cadences you can produce power at. You have no problem grinding it out, so forcing yourself to go the other way makes sense. Get a 15t cog and see how you feel with it, 14t if you still honestly spin out, but no lower.

Stay away from those "freewheel" yokes too. They're a fad anyway.

ROK ON

Thanks for quick replies. If I go ahead with the purchase I will give the 42/16 set up a go before deciding. It is equivalent to 50/19 on my compact chainset.
To get to 50/15 I would have to change rear cassette to a 13.

I like spinning and mashing so try to accommodate both.

Btw what is this stopping at lights ye speak of :-)

Greyspoke

For a long time I had been using 42-15 (75") on one bike and 46-16 (77") on another and found that size gear to be a reasonable compromise in that I could get up hills and wouldn't generally spin out too often. Recently though I've changed the gearing on one bike to 42-18 which gives a lower 63" gear. The reason was to try and get my legs spinning significantly faster as I was always a low cadence type of rider. Now I'm actually quite enjoying it even though, while my legs are going faster, my average speed is lower.
I was finding that with the higher gearing (and I know 75/77" gears are only middling gears) I often still felt it was a case of push-push rather than pedalling with a smooth cadence. Now though, with the 63" gear it really feels like I'm turning smooth circles.
Although I don't have a cadence sensor, with the fixed wheel you can work out your average cadence from your average speed, so a 27-28kph average equates to average cadences of 90-94rpm. Hope that's of some use!
...and don't forget you can use a larger chainring rather than a smaller sprocket to get a higher gear.